DDR4 - Allow SPD writes

    -DDR4 has 512-byte EEPROM with 2 256-byte pages.
     This commit contains the necessary page switching
     logic to support this.

Change-Id: Iaa8e3e344def98b71d6a9e9387c5e0d9137a0397
RTC:137707
ForwardPort: yes
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/797
Tested-by: Jenkins Server
Reviewed-by: Daniel M. Crowell <dcrowell@us.ibm.com>
Tested-by: Jenkins OP Build CI
Reviewed-by: William G. Hoffa <wghoffa@us.ibm.com>
Tested-by: Jenkins OP HW
Tested-by: FSP CI Jenkins
Reviewed-by: Matthew A. Ploetz <maploetz@us.ibm.com>
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/871

13 files changed, 1548 insertions, 372 deletions

diff --git a/src/include/usr/devicefw/driverif.H b/src/include/usr/devicefw/driverif.H
index 0842f734d..a148725b5 100644
--- a/src/include/usr/devicefw/driverif.H
+++ b/src/include/usr/devicefw/driverif.H
@@ -5,7 +5,7 @@
 /*                                                                        */
 /* OpenPOWER HostBoot Project                                             */
 /*                                                                        */
-/* Contributors Listed Below - COPYRIGHT 2011,2014                        */
+/* Contributors Listed Below - COPYRIGHT 2011,2016                        */
 /* [+] International Business Machines Corp.                              */
 /*                                                                        */
 /*                                                                        */
@@ -132,6 +132,31 @@ namespace DeviceFW
     #define DEVICE_I2C_ADDRESS_OFFSET( i_port, i_engine, i_devAddr, i_offset_len, i_offset)\
         DeviceFW::I2C,  DEVICE_I2C_PARMS(i_port, i_engine, i_devAddr, i_offset_len, i_offset)
 
+
+    /**
+     * Construct the device addressing parameters for locking the page
+     * attribute of an I2C master target
+     *
+     * @param[in] i_port - Which port to use from the I2C master.
+     * @param[in] i_engine - Which I2C master engine to use.
+     * @param[in] i_shouldLock - bool to determine whether we are
+     *                           attempting to lock or unlock the page.
+     * @param[in] i_desired_page - The EEPROM page we want to switch to
+     *                             iff a page switch is needed.
+     * @param[in] i_lockMutex - bool to determine whether we actually
+     *             want to lock the page mutex or not. This bool allows
+     *             us to switch pages mid read without hitting a deadlock.
+     */
+#define DEVICE_I2C_CONTROL_PAGE_OP( i_port, i_engine, i_shouldLock, i_desired_page, i_lockMutex )\
+            DeviceFW::I2C,\
+            static_cast<uint64_t>(i_port),\
+            static_cast<uint64_t>(i_engine),\
+            0xffffffff,\
+            static_cast<uint64_t>(i_shouldLock),\
+            static_cast<uint64_t>(i_desiredPage),\
+            static_cast<uint64_t>(i_lockMutex)
+
+
     /**
      * Construct the device addressing parameters for the Host I2C device ops.
      * @param[in] i_port - Which port to use from the I2C master.
diff --git a/src/include/usr/i2c/i2creasoncodes.H b/src/include/usr/i2c/i2creasoncodes.H
index fda1c142c..d46546ca2 100644
--- a/src/include/usr/i2c/i2creasoncodes.H
+++ b/src/include/usr/i2c/i2creasoncodes.H
@@ -5,7 +5,7 @@
 /*                                                                        */
 /* OpenPOWER HostBoot Project                                             */
 /*                                                                        */
-/* Contributors Listed Below - COPYRIGHT 2011,2015                        */
+/* Contributors Listed Below - COPYRIGHT 2011,2016                        */
 /* [+] International Business Machines Corp.                              */
 /*                                                                        */
 /*                                                                        */
@@ -59,6 +59,8 @@ enum i2cModuleId
     I2C_SEND_SLAVE_STOP                 = 0x09,
     I2C_PROCESS_ACTIVE_MASTERS          = 0x0A,
     I2C_FORCE_RESET_AND_UNLOCK          = 0x0B,
+    I2C_PAGE_LOCK_OP                    = 0x0C,
+    I2C_PAGE_UNLOCK_OP                  = 0x0D,
 };
 
 
@@ -86,6 +88,9 @@ enum i2cReasonCode
     I2C_RUNTIME_INTERFACE_ERR           = I2C_COMP_ID | 0x0D,   // Read/write unavailable at runtime
     I2C_RUNTIME_ERR                     = I2C_COMP_ID | 0x0E,   // Failed run-time operation
     I2C_RUNTIME_INVALID_OFFSET_LENGTH   = I2C_COMP_ID | 0x0F,   // Offset length of invalid size
+    I2C_INVALID_EEPROM_PAGE_MUTEX       = I2C_COMP_ID | 0x10,   // Error getting page mutex for i2c engine.
+    I2C_INVALID_EEPROM_PAGE_REQUEST     = I2C_COMP_ID | 0x11,   // Invalid EEPROM page request
+    I2C_FAILURE_UNLOCKING_EEPROM_PAGE   = I2C_COMP_ID | 0x12    // Error while attempting to unlock the eeprom page
 };
 
 
diff --git a/src/include/usr/vpd/spdenums.H b/src/include/usr/vpd/spdenums.H
index b728e3fbf..9decbe862 100644
--- a/src/include/usr/vpd/spdenums.H
+++ b/src/include/usr/vpd/spdenums.H
@@ -5,7 +5,7 @@
 /*                                                                        */
 /* OpenPOWER HostBoot Project                                             */
 /*                                                                        */
-/* Contributors Listed Below - COPYRIGHT 2013,2015                        */
+/* Contributors Listed Below - COPYRIGHT 2013,2016                        */
 /* [+] International Business Machines Corp.                              */
 /*                                                                        */
 /*                                                                        */
@@ -139,7 +139,7 @@ enum
     TRRDS_FINE_OFFSET                = SPD_FIRST_NORM_KEYWORD | 0x53,
     TCKMAX_FINE_OFFSET               = SPD_FIRST_NORM_KEYWORD | 0x54,
     BASE_CONFIG_CRC                  = SPD_FIRST_NORM_KEYWORD | 0x55,
-    MODULE_REVISION_CODE_DDR4        = SPD_FIRST_NORM_KEYWORD | 0x56,
+    MODULE_REVISION_CODE_DDR4        = MODULE_REVISION_CODE,
     DRAM_STEPPING                    = SPD_FIRST_NORM_KEYWORD | 0x57,
     MANUFACTURING_SECTION_CRC        = SPD_FIRST_NORM_KEYWORD | 0x58,
     SPD_LAST_NORM_KEYWORD            = SPD_FIRST_NORM_KEYWORD | 0x58,
diff --git a/src/usr/i2c/eepromdd.C b/src/usr/i2c/eepromdd.C
index 55b136cc1..dc3eaa9cc 100755
--- a/src/usr/i2c/eepromdd.C
+++ b/src/usr/i2c/eepromdd.C
@@ -5,7 +5,7 @@
 /*                                                                        */
 /* OpenPOWER HostBoot Project                                             */
 /*                                                                        */
-/* Contributors Listed Below - COPYRIGHT 2011,2015                        */
+/* Contributors Listed Below - COPYRIGHT 2011,2016                        */
 /* [+] International Business Machines Corp.                              */
 /*                                                                        */
 /*                                                                        */
@@ -114,7 +114,7 @@ errlHndl_t eepromPerformOp( DeviceFW::OperationType i_opType,
                             va_list i_args )
 {
     errlHndl_t err = NULL;
-    TARGETING::Target * theTarget = NULL;
+    TARGETING::Target * i2cMasterTarget = NULL;
     eeprom_addr_t i2cInfo;
 
     i2cInfo.chip = va_arg( i_args, uint64_t );
@@ -124,7 +124,7 @@ errlHndl_t eepromPerformOp( DeviceFW::OperationType i_opType,
                ENTER_MRK"eepromPerformOp()" );
 
     TRACUCOMP (g_trac_eeprom, ENTER_MRK"eepromPerformOp(): "
-               "i_opType=%d, chip=%d, offset=%d, len=%d",
+               "i_opType=%d, chip=%d, offset=%x, len=%d",
                (uint64_t) i_opType, i2cInfo.chip, i2cInfo.offset, io_buflen);
 
 #ifdef __HOSTBOOT_RUNTIME
@@ -149,7 +149,7 @@ errlHndl_t eepromPerformOp( DeviceFW::OperationType i_opType,
         // the I2C Master
         err = eepromGetI2CMasterTarget( i_target,
                                         i2cInfo,
-                                        theTarget );
+                                        i2cMasterTarget );
 
         if( err )
         {
@@ -196,10 +196,10 @@ errlHndl_t eepromPerformOp( DeviceFW::OperationType i_opType,
 
 #ifdef __HOSTBOOT_RUNTIME
         // Disable Sensor Cache if the I2C master target is MEMBUF
-        if( theTarget->getAttr<TARGETING::ATTR_TYPE>() ==
+        if( i2cMasterTarget->getAttr<TARGETING::ATTR_TYPE>() ==
                                                     TARGETING::TYPE_MEMBUF )
         {
-            err = I2C::i2cDisableSensorCache(theTarget,scacDisabled);
+            err = I2C::i2cDisableSensorCache(i2cMasterTarget,scacDisabled);
             if ( err )
             {
                 break;
@@ -210,7 +210,7 @@ errlHndl_t eepromPerformOp( DeviceFW::OperationType i_opType,
         // Do the read or write
         if( i_opType == DeviceFW::READ )
         {
-            err = eepromRead( theTarget,
+            err = eepromRead( i2cMasterTarget,
                               io_buffer,
                               io_buflen,
                               i2cInfo );
@@ -223,7 +223,7 @@ errlHndl_t eepromPerformOp( DeviceFW::OperationType i_opType,
         }
         else if( i_opType == DeviceFW::WRITE )
         {
-            err = eepromWrite( theTarget,
+            err = eepromWrite( i2cMasterTarget,
                                io_buffer,
                                io_buflen,
                                i2cInfo );
@@ -265,18 +265,18 @@ errlHndl_t eepromPerformOp( DeviceFW::OperationType i_opType,
     // Re-enable sensor cache if it was disabled before the eeprom op and
     // the I2C master target is MEMBUF
     if( scacDisabled &&
-       (theTarget->getAttr<TARGETING::ATTR_TYPE>() == TARGETING::TYPE_MEMBUF) )
+       (i2cMasterTarget->getAttr<TARGETING::ATTR_TYPE>() == TARGETING::TYPE_MEMBUF) )
     {
         errlHndl_t tmp_err = NULL;
 
-        tmp_err = I2C::i2cEnableSensorCache(theTarget);
+        tmp_err = I2C::i2cEnableSensorCache(i2cMasterTarget);
 
         if( err && tmp_err)
         {
             delete tmp_err;
             TRACFCOMP(g_trac_eeprom,
                 ERR_MRK" Enable Sensor Cache failed for HUID=0x%.8X",
-                TARGETING::get_huid(theTarget));
+                TARGETING::get_huid(i2cMasterTarget));
         }
         else if(tmp_err)
         {
@@ -308,12 +308,11 @@ errlHndl_t eepromPerformOp( DeviceFW::OperationType i_opType,
 //-------------------------------------------------------------------
 bool eepromPresence ( TARGETING::Target * i_target )
 {
-
-    TRACDCOMP(g_trac_eeprom, ENTER_MRK"eepromPresence()");
+    TRACUCOMP(g_trac_eeprom, ENTER_MRK"eepromPresence()");
 
     errlHndl_t err = NULL;
     bool l_present = false;
-    TARGETING::Target * theTarget = NULL;
+    TARGETING::Target * i2cMasterTarget = NULL;
 
     eeprom_addr_t i2cInfo;
 
@@ -337,7 +336,7 @@ bool eepromPresence ( TARGETING::Target * i_target )
         // the I2C Master
         err = eepromGetI2CMasterTarget( i_target,
                                         i2cInfo,
-                                        theTarget );
+                                        i2cMasterTarget );
 
         if( err )
         {
@@ -347,7 +346,7 @@ bool eepromPresence ( TARGETING::Target * i_target )
         }
 
         //Check for the target at the I2C level
-        l_present = I2C::i2cPresence(theTarget,
+        l_present = I2C::i2cPresence(i2cMasterTarget,
                           i2cInfo.port,
                           i2cInfo.engine,
                           i2cInfo.devAddr );
@@ -367,6 +366,126 @@ bool eepromPresence ( TARGETING::Target * i_target )
 #endif
 
 
+
+// ------------------------------------------------------------------
+// eepromPageOp
+// ------------------------------------------------------------------
+errlHndl_t eepromPageOp( TARGETING::Target * i_target,
+                         bool i_switchPage,
+                         bool i_lockMutex,
+                         bool & io_pageLocked,
+                         uint8_t i_desiredPage,
+                         eeprom_addr_t i_i2cInfo )
+{
+    TRACUCOMP(g_trac_eeprom,
+            ENTER_MRK"eepromPageOp()");
+
+    errlHndl_t l_err = NULL;
+    size_t l_placeHolderZero = 0;
+
+    do
+    {
+        // DDR4 requires EEPROM page to be selected before read/write operation.
+        // The following operation locks the EEPROM_PAGE attribute behind a
+        // mutex and switches all DIMMs on the I2C bus to the appropriate
+        // page.
+        if( i_i2cInfo.addrSize == ONE_BYTE_ADDR_PAGESELECT )
+        {
+
+            bool l_lockPage;
+            if( i_switchPage )
+            {
+                // we want to switch to the desired page
+                l_lockPage = true;
+                l_err = deviceOp( DeviceFW::WRITE,
+                                i_target,
+                                NULL,
+                                l_placeHolderZero,
+                                DEVICE_I2C_CONTROL_PAGE_OP(
+                                    i_i2cInfo.port,
+                                    i_i2cInfo.engine,
+                                    l_lockPage,
+                                    i_desiredPage,
+                                    i_lockMutex ));
+
+                if( l_err )
+                {
+                    TRACFCOMP(g_trac_eeprom,
+                            "eepromPageOp::Failed locking EEPROM page");
+                    break;
+                }
+                // if we make it this far, we successfully locked the page mutex
+                io_pageLocked = true;
+            }
+            else
+            {
+                // we only want to unlock the page
+                l_lockPage = false;
+                l_err = deviceOp( DeviceFW::WRITE,
+                                i_target,
+                                NULL,
+                                l_placeHolderZero,
+                                DEVICE_I2C_CONTROL_PAGE_OP(
+                                    i_i2cInfo.port,
+                                    i_i2cInfo.engine,
+                                    l_lockPage,
+                                    l_placeHolderZero,
+                                    i_lockMutex ));
+
+                if( l_err )
+                {
+                    TRACFCOMP( g_trac_eeprom,
+                            "eepromPageOp()::failed unlocking EEPROM page");
+                    break;
+                }
+                // if we make it this far, we successfully unlocked the page
+                io_pageLocked = false;
+            }
+        }
+    }while(0);
+    TRACUCOMP(g_trac_eeprom,
+            EXIT_MRK"eepromPageOp()");
+    return l_err;
+}
+
+
+// ------------------------------------------------------------------
+// crossesEepromPageBoundary
+// ------------------------------------------------------------------
+bool crossesEepromPageBoundary( uint64_t i_originalOffset,
+                                size_t i_originalLen,
+                                size_t & io_newLen,
+                                size_t & o_pageTwoBuflen,
+                                eeprom_addr_t i_i2cInfo )
+{
+    bool l_boundaryCrossed = false;
+    size_t l_higherBound = i_originalOffset + i_originalLen;
+
+    if( ( i_i2cInfo.addrSize == ONE_BYTE_ADDR_PAGESELECT ) &&
+      ( ( i_originalOffset < EEPROM_PAGE_SIZE ) &&
+        ( l_higherBound > EEPROM_PAGE_SIZE) ) )
+    {
+        // The read/write request crosses the boundary
+        l_boundaryCrossed = true;
+
+        // Calculate the new length of the page 0 buffer and the
+        // length of the page 1 buffer
+        o_pageTwoBuflen = l_higherBound - EEPROM_PAGE_SIZE;
+        io_newLen = i_originalLen - o_pageTwoBuflen;
+    }
+    else
+    {
+        // The read/write request does not cross the boundary.
+        // Update new length to be used by subsequent operations
+        io_newLen = i_originalLen;
+        o_pageTwoBuflen = 0;
+    }
+
+    return l_boundaryCrossed;
+}
+
+
+
 // ------------------------------------------------------------------
 // eepromRead
 // ------------------------------------------------------------------
@@ -376,33 +495,194 @@ errlHndl_t eepromRead ( TARGETING::Target * i_target,
                         eeprom_addr_t i_i2cInfo )
 {
     errlHndl_t err = NULL;
-    errlHndl_t err_NACK = NULL;
     uint8_t byteAddr[MAX_BYTE_ADDR];
     size_t byteAddrSize = 0;
-    bool unlock = false;
+    bool l_pageLocked = false;
+    uint8_t l_desiredPage = 0;
+    bool l_boundaryCrossed = false;
+    size_t l_readBuflen = 0;
+    size_t l_pageTwoBuflen = 0;
 
-    TRACDCOMP( g_trac_eeprom,
+    TRACUCOMP( g_trac_eeprom,
                ENTER_MRK"eepromRead()" );
 
     do
     {
-        TRACSCOMP( g_trac_eepromr,
+        TRACUCOMP( g_trac_eepromr,
                    "EEPROM READ  START : Chip: %02d : Offset %.2X : Len %d",
                    i_i2cInfo.chip, i_i2cInfo.offset, i_buflen );
 
-        err = eepromPrepareAddress( &byteAddr,
+
+        // Check to see if the Read operation straddles the EEPROM page
+        //boundary
+        l_boundaryCrossed = crossesEepromPageBoundary( i_i2cInfo.offset,
+                                                       i_buflen,
+                                                       l_readBuflen,
+                                                       l_pageTwoBuflen,
+                                                       i_i2cInfo );
+
+        // Set addressing parameters
+        err = eepromPrepareAddress( i_target,
+                                    &byteAddr,
                                     byteAddrSize,
-                                    i_i2cInfo );
+                                    l_desiredPage,
+                                    i_i2cInfo);
 
         if( err )
         {
+            TRACFCOMP(g_trac_eeprom,
+                    ERR_MRK"eepromRead()::eepromPrepareAddress()");
+            break;
+        }
+
+
+        // Attempt to lock page mutex
+        bool l_switchPage = true;
+        bool l_lockMutex = true;
+        err = eepromPageOp( i_target,
+                            l_switchPage,
+                            l_lockMutex,
+                            l_pageLocked,
+                            l_desiredPage,
+                            i_i2cInfo );
+
+        if( err )
+        {
+            TRACFCOMP(g_trac_eeprom,
+                    "eepromRead()::eepromPageOp()::failed locking page");
             break;
         }
 
         // Lock to sequence operations
         mutex_lock( &g_eepromMutex );
-        unlock = true;
 
+        // First Read. If Second read is necessary, this call will read
+        // everything from the original offset up to the 256th byte
+        err = eepromReadData( i_target,
+                              o_buffer,
+                              l_readBuflen,
+                              &byteAddr,
+                              byteAddrSize,
+                              i_i2cInfo );
+        if( err )
+        {
+            TRACFCOMP(g_trac_eeprom,
+                    "Failed reading data: original read");
+            break;
+        }
+
+
+        // Perform the second Read if necessary. Read starts at
+        // begining of EEPROM page 1 (offset=0x100) and reads the
+        // rest of the required data.
+        if( l_boundaryCrossed )
+        {
+            //Prepare the address to read at the start of EEPROM page one
+            i_i2cInfo.offset = EEPROM_PAGE_SIZE; // 0x100
+            err = eepromPrepareAddress( i_target,
+                                        &byteAddr,
+                                        byteAddrSize,
+                                        l_desiredPage,
+                                        i_i2cInfo );
+            if( err )
+            {
+                TRACFCOMP(g_trac_eeprom,
+                        "Error preparing address: second eeprom read");
+                break;
+            }
+
+            // Switch to the second EEPROM page
+            l_switchPage = true;
+            l_lockMutex = false;
+            err = eepromPageOp( i_target,
+                                l_switchPage,
+                                l_lockMutex,
+                                l_pageLocked,
+                                l_desiredPage,
+                                i_i2cInfo );
+
+            if( err )
+            {
+                TRACFCOMP( g_trac_eeprom,
+                        "Failed switching to EEPROM page 1 for second read op");
+                break;
+            }
+
+            // Perform the second read operation
+            err = eepromReadData(
+                           i_target,
+                           &(reinterpret_cast<uint8_t*>(o_buffer)[l_readBuflen]),
+                           l_pageTwoBuflen,
+                           &byteAddr,
+                           byteAddrSize,
+                           i_i2cInfo );
+
+            if( err )
+            {
+                TRACFCOMP( g_trac_eeprom,
+                         "Failed reading data: second read");
+                break;
+            }
+        }
+
+
+
+
+        TRACUCOMP( g_trac_eepromr,
+                   "EEPROM READ  END   : Chip: %02d : Offset %.2X : Len %d : %016llx",
+                   i_i2cInfo.chip, l_originalOffset, i_buflen,
+                   *((uint64_t*)o_buffer) );
+
+    } while( 0 );
+
+    // Unlock eeprom mutex no matter what
+    mutex_unlock( & g_eepromMutex );
+
+    // Whether we failed in the main routine or not, unlock page iff the page is locked
+    if( l_pageLocked )
+    {
+        errlHndl_t l_pageOpErrl = NULL;
+        bool l_switchPage = false;
+        bool l_lockMutex = false;
+        l_pageOpErrl = eepromPageOp( i_target,
+                                     l_switchPage,
+                                     l_lockMutex,
+                                     l_pageLocked,
+                                     l_desiredPage,
+                                     i_i2cInfo );
+        if( l_pageOpErrl )
+        {
+            TRACFCOMP(g_trac_eeprom,
+                    "eepromRead()::Failed unlocking page");
+            errlCommit(l_pageOpErrl, I2C_COMP_ID);
+        }
+
+    }
+
+    TRACUCOMP( g_trac_eeprom,
+               EXIT_MRK"eepromRead()" );
+
+    return err;
+} // end eepromRead
+
+
+// ------------------------------------------------------------------
+// eepromReadData
+// ------------------------------------------------------------------
+errlHndl_t eepromReadData( TARGETING::Target * i_target,
+                           void * o_buffer,
+                           size_t i_buflen,
+                           void * i_byteAddress,
+                           size_t i_byteAddressSize,
+                           eeprom_addr_t i_i2cInfo )
+{
+    errlHndl_t l_err = NULL;
+    errlHndl_t err_NACK = NULL;
+
+    TRACUCOMP(g_trac_eeprom,
+            ENTER_MRK"eepromReadData()");
+    do
+    {
         /***********************************************************/
         /* Attempt read multiple times ONLY on NACK fails         */
         /***********************************************************/
@@ -412,10 +692,10 @@ errlHndl_t eepromRead ( TARGETING::Target * i_target,
         {
 
             // Only write the byte address if we have data to write
-            if( 0 != byteAddrSize )
+            if( 0 != i_byteAddressSize )
             {
                 // Use the I2C OFFSET Interface for the READ
-                err = deviceOp( DeviceFW::READ,
+                l_err = deviceOp( DeviceFW::READ,
                                 i_target,
                                 o_buffer,
                                 i_buflen,
@@ -423,18 +703,18 @@ errlHndl_t eepromRead ( TARGETING::Target * i_target,
                                        i_i2cInfo.port,
                                        i_i2cInfo.engine,
                                        i_i2cInfo.devAddr,
-                                       byteAddrSize,
-                                       reinterpret_cast<uint8_t*>(&byteAddr)));
+                                       i_byteAddressSize,
+                                       reinterpret_cast<uint8_t*>(i_byteAddress)));
 
-                if( err )
+                if( l_err )
                 {
                     TRACFCOMP(g_trac_eeprom,
-                              ERR_MRK"eepromRead(): I2C Read-Offset failed on "
+                              ERR_MRK"eepromReadData(): I2C Read-Offset failed on "
                               "%d/%d/0x%X aS=%d",
                               i_i2cInfo.port, i_i2cInfo.engine,
-                              i_i2cInfo.devAddr, byteAddrSize);
-                    TRACFBIN(g_trac_eeprom, "byteAddr[]",
-                             &byteAddr, byteAddrSize);
+                              i_i2cInfo.devAddr, i_byteAddressSize);
+                    TRACFBIN(g_trac_eeprom, "i_byteAddress[]",
+                             i_byteAddress, i_byteAddressSize);
 
                     // Don't break here -- error handled below
                 }
@@ -442,7 +722,7 @@ errlHndl_t eepromRead ( TARGETING::Target * i_target,
             else
             {
                 // Do the actual read via I2C
-                err = deviceOp( DeviceFW::READ,
+                l_err = deviceOp( DeviceFW::READ,
                                 i_target,
                                 o_buffer,
                                 i_buflen,
@@ -450,10 +730,10 @@ errlHndl_t eepromRead ( TARGETING::Target * i_target,
                                                     i_i2cInfo.engine,
                                                     i_i2cInfo.devAddr ) );
 
-                if( err )
+                if( l_err )
                 {
                     TRACFCOMP(g_trac_eeprom,
-                              ERR_MRK"eepromRead(): I2C Read failed on "
+                              ERR_MRK"eepromReadData(): I2C Read failed on "
                               "%d/%d/0x%0X", i_i2cInfo.port, i_i2cInfo.engine,
                               i_i2cInfo.devAddr);
 
@@ -461,21 +741,21 @@ errlHndl_t eepromRead ( TARGETING::Target * i_target,
                 }
             }
 
-            if ( err == NULL )
+            if ( l_err == NULL )
             {
                 // Operation completed successfully
                 // break from retry loop
                 break;
             }
-            else if ( err->reasonCode() != I2C::I2C_NACK_ONLY_FOUND )
+            else if ( l_err->reasonCode() != I2C::I2C_NACK_ONLY_FOUND )
             {
                 // Only retry on NACK failures: break from retry loop
-                TRACFCOMP( g_trac_eeprom, ERR_MRK"eepromRead(): Non-Nack "
+                TRACFCOMP( g_trac_eeprom, ERR_MRK"eepromReadData(): Non-Nack "
                            "Error: rc=0x%X, tgt=0x%X, No Retry (retry=%d)",
-                            err->reasonCode(),
+                            l_err->reasonCode(),
                             TARGETING::get_huid(i_target), retry);
 
-                err->collectTrace(EEPROM_COMP_NAME);
+                l_err->collectTrace(EEPROM_COMP_NAME);
 
                 // break from retry loop
                 break;
@@ -489,9 +769,9 @@ errlHndl_t eepromRead ( TARGETING::Target * i_target,
                     if ( err_NACK == NULL )
                     {
                         // Save original NACK error
-                        err_NACK = err;
+                        err_NACK = l_err;
 
-                        TRACFCOMP( g_trac_eeprom, ERR_MRK"eepromRead(): "
+                        TRACFCOMP( g_trac_eeprom, ERR_MRK"eepromReadData(): "
                                    "NACK Error rc=0x%X, eid=0x%X, tgt=0x%X, "
                                    "retry/MAX=%d/%d. Save error and retry",
                                    err_NACK->reasonCode(),
@@ -504,11 +784,11 @@ errlHndl_t eepromRead ( TARGETING::Target * i_target,
                     else
                     {
                         // Add data to original NACK error
-                        TRACFCOMP( g_trac_eeprom, ERR_MRK"eepromRead(): "
+                        TRACFCOMP( g_trac_eeprom, ERR_MRK"eepromReadData(): "
                                    "Another NACK Error rc=0x%X, eid=0x%X "
                                    "plid=0x%X, tgt=0x%X, retry/MAX=%d/%d. "
                                    "Delete error and retry",
-                                   err->reasonCode(), err->eid(), err->plid(),
+                                   l_err->reasonCode(), l_err->eid(), l_err->plid(),
                                    TARGETING::get_huid(i_target),
                                    retry, EEPROM_MAX_NACK_RETRIES);
 
@@ -517,8 +797,8 @@ errlHndl_t eepromRead ( TARGETING::Target * i_target,
                                   .addToLog(err_NACK);
 
                         // Delete this new NACK error
-                        delete err;
-                        err = NULL;
+                        delete l_err;
+                        l_err = NULL;
                     }
 
                     // continue to retry
@@ -526,14 +806,14 @@ errlHndl_t eepromRead ( TARGETING::Target * i_target,
                 }
                 else // no more retries: trace and break
                 {
-                    TRACFCOMP( g_trac_eeprom, ERR_MRK"eepromRead(): "
+                    TRACFCOMP( g_trac_eeprom, ERR_MRK"eepromReadData(): "
                                "Error rc=0x%X, eid=%d, tgt=0x%X. No More "
                                "Retries (retry/MAX=%d/%d). Returning Error",
-                               err->reasonCode(), err->eid(),
+                               l_err->reasonCode(), l_err->eid(),
                                TARGETING::get_huid(i_target),
                                retry, EEPROM_MAX_NACK_RETRIES);
 
-                    err->collectTrace(EEPROM_COMP_NAME);
+                    l_err->collectTrace(EEPROM_COMP_NAME);
 
                     // break from retry loop
                     break;
@@ -545,12 +825,12 @@ errlHndl_t eepromRead ( TARGETING::Target * i_target,
         // Handle saved NACK error, if any
         if (err_NACK)
         {
-            if (err)
+            if (l_err)
             {
                 // commit original NACK error with new err PLID
-                err_NACK->plid(err->plid());
-                TRACFCOMP(g_trac_eeprom, "eepromRead(): Committing saved NACK "
-                          "err eid=0x%X with plid of returned err: 0x%X",
+                err_NACK->plid(l_err->plid());
+                TRACFCOMP(g_trac_eeprom, "eepromReadData(): Committing saved NACK "
+                          "l_err eid=0x%X with plid of returned err: 0x%X",
                           err_NACK->eid(), err_NACK->plid());
 
                 ERRORLOG::ErrlUserDetailsTarget(i_target)
@@ -561,7 +841,7 @@ errlHndl_t eepromRead ( TARGETING::Target * i_target,
             else
             {
                 // Since we eventually succeeded, delete original NACK error
-                TRACFCOMP(g_trac_eeprom, "eepromRead(): Op successful, "
+                TRACFCOMP(g_trac_eeprom, "eepromReadData(): Op successful, "
                           "deleting saved NACK err eid=0x%X, plid=0x%X",
                           err_NACK->eid(), err_NACK->plid());
 
@@ -570,28 +850,13 @@ errlHndl_t eepromRead ( TARGETING::Target * i_target,
             }
         }
 
+    }while( 0 );
 
-        mutex_unlock( &g_eepromMutex );
-        unlock = false;
-
-        TRACSCOMP( g_trac_eepromr,
-                   "EEPROM READ  END   : Chip: %02d : Offset %.2X : Len %d : %016llx",
-                   i_i2cInfo.chip, i_i2cInfo.offset, i_buflen,
-                   *((uint64_t*)o_buffer) );
-
-    } while( 0 );
+    TRACUCOMP(g_trac_eeprom,
+            EXIT_MRK"eepromReadData");
+    return l_err;
+}
 
-    // Catch it if we break out early.
-    if( unlock )
-    {
-        mutex_unlock( & g_eepromMutex );
-    }
-
-    TRACDCOMP( g_trac_eeprom,
-               EXIT_MRK"eepromRead()" );
-
-    return err;
-} // end eepromRead
 
 
 // ------------------------------------------------------------------
@@ -603,31 +868,62 @@ errlHndl_t eepromWrite ( TARGETING::Target * i_target,
                          eeprom_addr_t i_i2cInfo )
 {
     errlHndl_t err = NULL;
-    errlHndl_t err_NACK = NULL;
+    uint8_t l_desiredPage = 0;
+    uint8_t l_originalPage = 0;
     uint8_t byteAddr[MAX_BYTE_ADDR];
     size_t byteAddrSize = 0;
     uint8_t * newBuffer = NULL;
     bool needFree = false;
     bool unlock = false;
+    bool l_pageLocked = false;
     uint32_t data_left = 0;
     uint32_t diff_wps = 0;
+    size_t l_writeBuflen = 0;
+    size_t l_bytesIntoSecondPage = 0;
 
     TRACDCOMP( g_trac_eeprom,
                ENTER_MRK"eepromWrite()" );
 
     do
     {
-        TRACSCOMP( g_trac_eepromr,
+        TRACUCOMP( g_trac_eeprom,
                    "EEPROM WRITE START : Chip: %02d : Offset %.2X : Len %d : %016llx",
                    i_i2cInfo.chip, i_i2cInfo.offset, io_buflen,
                    *((uint64_t*)io_buffer) );
 
-        err = eepromPrepareAddress( &byteAddr,
+
+        // Prepare address parameters
+        err = eepromPrepareAddress( i_target,
+                                    &byteAddr,
                                     byteAddrSize,
-                                    i_i2cInfo );
+                                    l_desiredPage,
+                                    i_i2cInfo);
 
         if( err )
         {
+            TRACFCOMP(g_trac_eeprom,
+                    ERR_MRK"eepromWrite()::eepromPrepareAddress()");
+            break;
+        }
+
+        // Save original Page
+        l_originalPage = l_desiredPage;
+        // Attempt to lock page mutex
+        bool l_switchPage = true; // true: Lock and switch page
+                                  // false: Just unlock page
+        bool l_lockMutex = true;  // true: Lock mutex
+                                  // false: Skip locking mutex step
+        err = eepromPageOp( i_target,
+                            l_switchPage,
+                            l_lockMutex,
+                            l_pageLocked,
+                            l_desiredPage,
+                            i_i2cInfo );
+
+        if( err )
+        {
+            TRACFCOMP(g_trac_eeprom,
+                    "eepromWrite()::Failed locking EEPROM page");
             break;
         }
 
@@ -677,10 +973,7 @@ errlHndl_t eepromWrite ( TARGETING::Target * i_target,
         size_t loop_data_length = 0;
         size_t total_bytes_written = 0;
 
-
-        for ( uint64_t i = 0 ;
-              total_bytes_written < io_buflen ;
-              i++ )
+        while( total_bytes_written < io_buflen )
         {
             // Determine how much data can be written in this loop
             // Can't go over a writePageSize boundary
@@ -701,187 +994,91 @@ errlHndl_t eepromWrite ( TARGETING::Target * i_target,
                     loop_data_length );
 
 
+
+            // Check if loop_data_length crosses the EEPROM page boundary
+            crossesEepromPageBoundary( i_i2cInfo.offset,
+                                       loop_data_length,
+                                       l_writeBuflen,
+                                       l_bytesIntoSecondPage,
+                                       i_i2cInfo );
+
             // Setup offset/address parms
-            err = eepromPrepareAddress(  &byteAddr,
-                                         byteAddrSize,
-                                         i_i2cInfo );
+            err = eepromPrepareAddress( i_target,
+                                        &byteAddr,
+                                        byteAddrSize,
+                                        l_desiredPage,
+                                        i_i2cInfo );
+
 
             if( err )
             {
+                TRACFCOMP(g_trac_eeprom,
+                         ERR_MRK"eepromWrite::eepromPrepareAddress()::loop version");
                 break;
             }
 
-            TRACUCOMP(g_trac_eeprom,"eepromWrite() Loop: %d/%d/0x%X "
-                "loop=%d, l_d_l=%d, offset=0x%X, bAS=%d, diffs=%d/%d",
-                i_i2cInfo.port, i_i2cInfo.engine, i_i2cInfo.devAddr,
-                i, loop_data_length, i_i2cInfo.offset, byteAddrSize,
-                data_left, diff_wps);
-
-            /***********************************************************/
-            /* Attempt write multiple times ONLY on NACK fails         */
-            /***********************************************************/
-            for (uint8_t retry = 0;
-                 retry <= EEPROM_MAX_NACK_RETRIES;
-                 retry++)
-            {
-                // Do the actual data write
-                err = deviceOp( DeviceFW::WRITE,
-                                i_target,
-                                newBuffer,
-                                loop_data_length,
-                                DEVICE_I2C_ADDRESS_OFFSET(
-                                               i_i2cInfo.port,
-                                               i_i2cInfo.engine,
-                                               i_i2cInfo.devAddr,
-                                               byteAddrSize,
-                                               reinterpret_cast<uint8_t*>(
-                                               &byteAddr)));
 
 
-                if ( err == NULL )
-                {
-                    // Operation completed successfully
-                    // break from retry loop
-                    break;
-                }
-                else if ( err->reasonCode() != I2C::I2C_NACK_ONLY_FOUND )
+            // if desired page has changed mid-request, switch to correct page
+            if( l_desiredPage != l_originalPage )
+            {
+                l_switchPage = true;
+                l_lockMutex = false;
+                err = eepromPageOp( i_target,
+                                    l_switchPage,
+                                    l_lockMutex,
+                                    l_pageLocked,
+                                    l_desiredPage,
+                                    i_i2cInfo );
+                if( err )
                 {
-                    // Only retry on NACK failures: break from retry loop
-                    TRACFCOMP(g_trac_eeprom, ERR_MRK"eepromWrite(): I2C "
-                              "Write Non-NACK fail %d/%d/0x%X loop=%d, "
-                              "ldl=%d, offset=0x%X, aS=%d, retry=%d",
-                              i_i2cInfo.port, i_i2cInfo.engine,
-                              i_i2cInfo.devAddr, i, loop_data_length,
-                              i_i2cInfo.offset, i_i2cInfo.addrSize, retry);
-
-                    err->collectTrace(EEPROM_COMP_NAME);
-
-                    // break from retry loop
+                    TRACFCOMP( g_trac_eeprom,
+                            "Failed switching to new EEPROM page!");
                     break;
                 }
-                else // Handle NACK error
-                {
-                    TRACFCOMP(g_trac_eeprom, ERR_MRK"eepromWrite(): I2C "
-                              "Write NACK fail %d/%d/0x%X loop=%d, "
-                              "ldl=%d, offset=0x%X, aS=%d",
-                              i_i2cInfo.port, i_i2cInfo.engine,
-                              i_i2cInfo.devAddr, i, loop_data_length,
-                              i_i2cInfo.offset, i_i2cInfo.addrSize);
-
-                    // If op will be attempted again: save error and continue
-                    if ( retry < EEPROM_MAX_NACK_RETRIES )
-                    {
-                        // Only save original NACK error
-                        if ( err_NACK == NULL )
-                        {
-                            // Save original NACK error
-                            err_NACK = err;
-
-                            TRACFCOMP( g_trac_eeprom, ERR_MRK"eepromWrite(): "
-                                       "Error rc=0x%X, eid=0x%X plid=0x%X, "
-                                       "tgt=0x%X, retry/MAX=%d/%d. Save error "
-                                       "and retry",
-                                       err_NACK->reasonCode(),
-                                       err_NACK->eid(),
-                                       err_NACK->plid(),
-                                       TARGETING::get_huid(i_target),
-                                       retry, EEPROM_MAX_NACK_RETRIES);
-
-                            err_NACK->collectTrace(EEPROM_COMP_NAME);
-                        }
-                        else
-                        {
-                            // Add data to original NACK error
-                            TRACFCOMP( g_trac_eeprom, ERR_MRK"eepromWrite(): "
-                                       "Another NACK Error rc=0x%X, eid=0x%X "
-                                       "plid=0x%X, tgt=0x%X, retry/MAX=%d/%d. "
-                                       "Delete error and retry",
-                                       err->reasonCode(), err->eid(),
-                                       err->plid(),
-                                       TARGETING::get_huid(i_target),
-                                       retry, EEPROM_MAX_NACK_RETRIES);
-
-                            ERRORLOG::ErrlUserDetailsString(
-                                      "Another NACK ERROR found")
-                                      .addToLog(err_NACK);
-
-                            // Delete this new NACK error
-                            delete err;
-                            err = NULL;
-                        }
-
-                        // continue to retry
-                        continue;
-                    }
-                    else // no more retries: trace and break
-                    {
-                        TRACFCOMP( g_trac_eeprom, ERR_MRK"eepromWrite(): "
-                                   "Error rc=0x%X, tgt=0x%X. No More Retries "
-                                   "(retry/MAX=%d/%d). Returning Error",
-                                   err->reasonCode(),
-                                   TARGETING::get_huid(i_target),
-                                   retry, EEPROM_MAX_NACK_RETRIES);
-
-                        err->collectTrace(EEPROM_COMP_NAME);
-
-                        // break from retry loop
-                        break;
-                    }
-                }
+                l_originalPage = l_desiredPage;
+            }
 
-            } // end of retry loop
-            /***********************************************************/
 
-            // Handle saved NACK errors, if any
-            if (err_NACK)
-            {
-                if (err)
-                {
-                    // commit original NACK error with new err PLID
-                    err_NACK->plid(err->plid());
-                    TRACFCOMP(g_trac_eeprom, "eepromWrite(): Committing saved "
-                              "NACK err eid=0x%X with plid of returned err: "
-                              "0x%X",
-                              err_NACK->eid(), err_NACK->plid());
 
-                    ERRORLOG::ErrlUserDetailsTarget(i_target)
-                                                    .addToLog(err_NACK);
+            TRACUCOMP(g_trac_eeprom,"eepromWrite() Loop: %d/%d/0x%X "
+                "loop=%d, writeBuflen=%d, offset=0x%X, bAS=%d, diffs=%d/%d",
+                i_i2cInfo.port, i_i2cInfo.engine, i_i2cInfo.devAddr,
+                i, l_writeBuflen, i_i2cInfo.offset, byteAddrSize,
+                data_left, diff_wps);
 
-                    errlCommit(err_NACK, EEPROM_COMP_ID);
-                }
-                else
-                {
-                    // Since we eventually succeeded, delete original NACK error
-                    TRACFCOMP(g_trac_eeprom, "eepromWrite(): Op successful, "
-                              "deleting saved NACK err eid=0x%X, plid=0x%X",
-                              err_NACK->eid(), err_NACK->plid());
 
-                    delete err_NACK;
-                    err_NACK = NULL;
-                }
-            }
+            // Perform the requested write operation
+            err = eepromWriteData( i_target,
+                                   newBuffer,
+                                   l_writeBuflen,
+                                   &byteAddr,
+                                   byteAddrSize,
+                                   i_i2cInfo );
 
             if ( err )
             {
                 // Can't assume that anything was written if
                 // there was an error, so no update to total_bytes_written
                 // for this loop
+                TRACFCOMP(g_trac_eeprom,
+                        "Failed writing data: original eeprom write");
                 break;
             }
 
             // Wait for EEPROM to write data to its internal memory
             // i_i2cInfo.writeCycleTime value in milliseconds
-            nanosleep(0, i_i2cInfo.writeCycleTime * NS_PER_MSEC);
+            nanosleep( 0, i_i2cInfo.writeCycleTime * NS_PER_MSEC );
 
             // Update how much data was written
-            total_bytes_written += loop_data_length;
+            total_bytes_written += l_writeBuflen;
 
             // Update offset
-            i_i2cInfo.offset += loop_data_length;
+            i_i2cInfo.offset += l_writeBuflen;
 
             TRACUCOMP(g_trac_eeprom,"eepromWrite() Loop %d End: "
-                      "l_d_l=%d, offset=0x%X, t_b_w=%d, io_buflen=%d",
-                      i, loop_data_length, i_i2cInfo.offset,
+                      "writeBuflen=%d, offset=0x%X, t_b_w=%d, io_buflen=%d",
+                      i, l_writeBuflen, i_i2cInfo.offset,
                       total_bytes_written, io_buflen);
 
         } // end of write for-loop
@@ -890,14 +1087,10 @@ errlHndl_t eepromWrite ( TARGETING::Target * i_target,
         mutex_unlock( &g_eepromMutex );
         unlock = false;
 
+
         // Set how much data was actually written
         io_buflen = total_bytes_written;
 
-        if( err )
-        {
-            // Leave do-while loop
-            break;
-        }
 
         TRACSCOMP( g_trac_eepromr,
                    "EEPROM WRITE END   : Chip: %02d : Offset %.2X : Len %d",
@@ -916,6 +1109,30 @@ errlHndl_t eepromWrite ( TARGETING::Target * i_target,
         mutex_unlock( & g_eepromMutex );
     }
 
+
+    // Whether we failed in the main routine or not, unlock the page iff it is already
+    // locked
+    if( l_pageLocked )
+    {
+        errlHndl_t l_pageOpErrl = NULL;
+
+        bool l_switchPage = false;
+        bool l_lockMutex = false;
+        l_pageOpErrl = eepromPageOp( i_target,
+                                     l_switchPage,
+                                     l_lockMutex,
+                                     l_pageLocked,
+                                     l_desiredPage,
+                                     i_i2cInfo );
+        if( l_pageOpErrl )
+        {
+            TRACFCOMP(g_trac_eeprom,
+                    "eepromWrite()::Failed unlocking page");
+            errlCommit(l_pageOpErrl, I2C_COMP_ID);
+        }
+
+    }
+
     TRACDCOMP( g_trac_eeprom,
                EXIT_MRK"eepromWrite()" );
 
@@ -924,15 +1141,185 @@ errlHndl_t eepromWrite ( TARGETING::Target * i_target,
 } // end eepromWrite
 
 
+
+// ------------------------------------------------------------------
+// eepromWriteData
+// ------------------------------------------------------------------
+errlHndl_t eepromWriteData( TARGETING::Target * i_target,
+                            void * i_dataToWrite,
+                            size_t i_dataLen,
+                            void * i_byteAddress,
+                            size_t i_byteAddressSize,
+                            eeprom_addr_t i_i2cInfo )
+{
+    TRACDCOMP( g_trac_eeprom,
+               ENTER_MRK"eepromWriteData()");
+    errlHndl_t err = NULL;
+    errlHndl_t err_NACK = NULL;
+    do
+    {
+         /***********************************************************/
+         /* Attempt write multiple times ONLY on NACK fails         */
+         /***********************************************************/
+        for (uint8_t retry = 0;
+              retry <= EEPROM_MAX_NACK_RETRIES;
+              retry++)
+         {
+             // Do the actual data write
+             err = deviceOp( DeviceFW::WRITE,
+                             i_target,
+                             i_dataToWrite,
+                             i_dataLen,
+                             DEVICE_I2C_ADDRESS_OFFSET(
+                                            i_i2cInfo.port,
+                                            i_i2cInfo.engine,
+                                            i_i2cInfo.devAddr,
+                                            i_byteAddressSize,
+                                            reinterpret_cast<uint8_t*>(
+                                            i_byteAddress)));
+
+
+             if ( err == NULL )
+             {
+                 // Operation completed successfully
+                 // break from retry loop
+                 break;
+             }
+             else if ( err->reasonCode() != I2C::I2C_NACK_ONLY_FOUND )
+             {
+                 // Only retry on NACK failures: break from retry loop
+                 TRACFCOMP(g_trac_eeprom, ERR_MRK"eepromWriteData(): I2C "
+                           "Write Non-NACK fail %d/%d/0x%X, "
+                           "ldl=%d, offset=0x%X, aS=%d, retry=%d",
+                           i_i2cInfo.port, i_i2cInfo.engine,
+                           i_i2cInfo.devAddr, i_dataLen,
+                           i_i2cInfo.offset, i_i2cInfo.addrSize, retry);
+
+                 err->collectTrace(EEPROM_COMP_NAME);
+
+                 // break from retry loop
+                 break;
+             }
+             else // Handle NACK error
+             {
+                 TRACFCOMP(g_trac_eeprom, ERR_MRK"eepromWriteData(): I2C "
+                           "Write NACK fail %d/%d/0x%X, "
+                           "ldl=%d, offset=0x%X, aS=%d, writePageSize = %x",
+                           i_i2cInfo.port, i_i2cInfo.engine,
+                           i_i2cInfo.devAddr, i_dataLen,
+                           i_i2cInfo.offset, i_i2cInfo.addrSize,
+                           i_i2cInfo.writePageSize);
+
+                 // If op will be attempted again: save error and continue
+                 if ( retry < EEPROM_MAX_NACK_RETRIES )
+                 {
+                     // Only save original NACK error
+                     if ( err_NACK == NULL )
+                     {
+                         // Save original NACK error
+                         err_NACK = err;
+
+                         TRACFCOMP( g_trac_eeprom, ERR_MRK"eepromWriteData(): "
+                                    "Error rc=0x%X, eid=0x%X plid=0x%X, "
+                                    "tgt=0x%X, retry/MAX=%d/%d. Save error "
+                                    "and retry",
+                                    err_NACK->reasonCode(),
+                                    err_NACK->eid(),
+                                    err_NACK->plid(),
+                                    TARGETING::get_huid(i_target),
+                                    retry, EEPROM_MAX_NACK_RETRIES);
+
+                         err_NACK->collectTrace(EEPROM_COMP_NAME);
+                     }
+                     else
+                     {
+                         // Add data to original NACK error
+                         TRACFCOMP( g_trac_eeprom, ERR_MRK"eepromWriteData(): "
+                                    "Another NACK Error rc=0x%X, eid=0x%X "
+                                    "plid=0x%X, tgt=0x%X, retry/MAX=%d/%d. "
+                                    "Delete error and retry",
+                                    err->reasonCode(), err->eid(),
+                                    err->plid(),
+                                    TARGETING::get_huid(i_target),
+                                    retry, EEPROM_MAX_NACK_RETRIES);
+
+                         ERRORLOG::ErrlUserDetailsString(
+                                   "Another NACK ERROR found")
+                                   .addToLog(err_NACK);
+
+                         // Delete this new NACK error
+                         delete err;
+                         err = NULL;
+                     }
+
+                     // continue to retry
+                     continue;
+                 }
+                 else // no more retries: trace and break
+                 {
+                     TRACFCOMP( g_trac_eeprom, ERR_MRK"eepromWriteData(): "
+                                "Error rc=0x%X, tgt=0x%X. No More Retries "
+                                "(retry/MAX=%d/%d). Returning Error",
+                                err->reasonCode(),
+                                TARGETING::get_huid(i_target),
+                                retry, EEPROM_MAX_NACK_RETRIES);
+
+                     err->collectTrace(EEPROM_COMP_NAME);
+
+                     // break from retry loop
+                     break;
+                 }
+             }
+
+         } // end of retry loop
+         /***********************************************************/
+
+         // Handle saved NACK errors, if any
+         if (err_NACK)
+         {
+             if (err)
+             {
+                 // commit original NACK error with new err PLID
+                 err_NACK->plid(err->plid());
+                 TRACFCOMP(g_trac_eeprom, "eepromWriteData(): Committing saved "
+                           "NACK err eid=0x%X with plid of returned err: "
+                           "0x%X",
+                           err_NACK->eid(), err_NACK->plid());
+
+                 ERRORLOG::ErrlUserDetailsTarget(i_target)
+                                                 .addToLog(err_NACK);
+
+                 errlCommit(err_NACK, EEPROM_COMP_ID);
+             }
+             else
+             {
+                 // Since we eventually succeeded, delete original NACK error
+                 TRACFCOMP(g_trac_eeprom, "eepromWriteData(): Op successful, "
+                           "deleting saved NACK err eid=0x%X, plid=0x%X",
+                           err_NACK->eid(), err_NACK->plid());
+
+                 delete err_NACK;
+                 err_NACK = NULL;
+             }
+         }
+    }while( 0 );
+    TRACDCOMP( g_trac_eeprom,
+            EXIT_MRK"eepromWriteData()");
+    return err;
+}
+
+
+
 // ------------------------------------------------------------------
 // eepromPrepareAddress
 // ------------------------------------------------------------------
-errlHndl_t eepromPrepareAddress ( void * io_buffer,
+errlHndl_t eepromPrepareAddress ( TARGETING::Target * i_target,
+                                  void * io_buffer,
                                   size_t & o_bufSize,
+                                  uint8_t & o_desiredPage,
                                   eeprom_addr_t i_i2cInfo )
 {
     errlHndl_t err = NULL;
-
     o_bufSize = 0;
 
     TRACDCOMP( g_trac_eeprom,
@@ -954,6 +1341,21 @@ errlHndl_t eepromPrepareAddress ( void * io_buffer,
                 *((uint8_t*)io_buffer+1) = (i_i2cInfo.offset & 0x00FFull);
                 break;
 
+            case ONE_BYTE_ADDR_PAGESELECT:
+                // If the offset is less than 256 bytes, report page zero, else page 1
+                if( i_i2cInfo.offset >= EEPROM_PAGE_SIZE )
+                {
+                    o_desiredPage = 1;
+                }
+                else
+                {
+                    o_desiredPage = 0;
+                }
+                o_bufSize = 1;
+                memset( io_buffer, 0x0, o_bufSize );
+                *((uint8_t*)io_buffer) = (i_i2cInfo.offset & 0xFFull);
+                break;
+
             case ONE_BYTE_ADDR:
                 o_bufSize = 1;
                 memset( io_buffer, 0x0, o_bufSize );
@@ -1058,7 +1460,6 @@ errlHndl_t eepromReadAttributes ( TARGETING::Target * i_target,
                 break;
 
             case SBE_BACKUP:
-
                 if( (!i_target->
                         tryGetAttr<TARGETING::ATTR_EEPROM_SBE_BACKUP_INFO>
                         ( reinterpret_cast<
@@ -1132,22 +1533,26 @@ errlHndl_t eepromReadAttributes ( TARGETING::Target * i_target,
         }
 
         // Successful reading of Attribute, so extract the data
-        o_i2cInfo.port          = eepromData.port;
-        o_i2cInfo.devAddr       = eepromData.devAddr;
-        o_i2cInfo.engine        = eepromData.engine;
-        o_i2cInfo.i2cMasterPath = eepromData.i2cMasterPath;
-        o_i2cInfo.writePageSize = eepromData.writePageSize;
-        o_i2cInfo.devSize_KB    = eepromData.maxMemorySizeKB;
+        o_i2cInfo.port           = eepromData.port;
+        o_i2cInfo.devAddr        = eepromData.devAddr;
+        o_i2cInfo.engine         = eepromData.engine;
+        o_i2cInfo.i2cMasterPath  = eepromData.i2cMasterPath;
+        o_i2cInfo.writePageSize  = eepromData.writePageSize;
+        o_i2cInfo.devSize_KB     = eepromData.maxMemorySizeKB;
         o_i2cInfo.writeCycleTime = eepromData.writeCycleTime;
 
         // Convert attribute info to eeprom_addr_size_t enum
-        if ( eepromData.byteAddrOffset == 0x2 )
+        if ( eepromData.byteAddrOffset == 0x3 )
+        {
+            o_i2cInfo.addrSize = ONE_BYTE_ADDR;
+        }
+        else if ( eepromData.byteAddrOffset == 0x2 )
         {
             o_i2cInfo.addrSize = TWO_BYTE_ADDR;
         }
         else if ( eepromData.byteAddrOffset == 0x1 )
         {
-            o_i2cInfo.addrSize = ONE_BYTE_ADDR;
+            o_i2cInfo.addrSize = ONE_BYTE_ADDR_PAGESELECT;
         }
         else if ( eepromData.byteAddrOffset == 0x0 )
         {
diff --git a/src/usr/i2c/eepromdd.H b/src/usr/i2c/eepromdd.H
index 234be5eb1..19eb0a7e3 100755
--- a/src/usr/i2c/eepromdd.H
+++ b/src/usr/i2c/eepromdd.H
@@ -5,7 +5,7 @@
 /*                                                                        */
 /* OpenPOWER HostBoot Project                                             */
 /*                                                                        */
-/* Contributors Listed Below - COPYRIGHT 2011,2015                        */
+/* Contributors Listed Below - COPYRIGHT 2011,2016                        */
 /* [+] International Business Machines Corp.                              */
 /*                                                                        */
 /*                                                                        */
@@ -46,9 +46,10 @@ namespace EEPROM
 */
 typedef enum
 {
-    ZERO_BYTE_ADDR  = 0,
-    ONE_BYTE_ADDR   = 1,
-    TWO_BYTE_ADDR   = 2,
+    ZERO_BYTE_ADDR             = 0,
+    ONE_BYTE_ADDR_PAGESELECT   = 1,  // page select
+    TWO_BYTE_ADDR              = 2,
+    ONE_BYTE_ADDR              = 3,
     LAST_DEVICE_TYPE
 } eeprom_addr_size_t;
 
@@ -70,6 +71,14 @@ typedef struct
     uint64_t writeCycleTime;  // in milliseconds
 } eeprom_addr_t;
 
+/*
+ * @brief Miscellaneous enums for EEPROM
+ */
+enum
+{
+    EEPROM_PAGE_SIZE = 0x100
+};
+
 /**
 *
 * @brief Perform an EEPROM access operation.
@@ -109,6 +118,60 @@ errlHndl_t eepromPerformOp( DeviceFW::OperationType i_opType,
                             va_list i_args );
 
 /**
+ *
+ * @brief Perform operations to lock and unlock the page mutex
+ *
+ * @param[in] i_target - the target to lock the page for
+ * @param[in] i_switchPage - bool to tell the function whether we are
+ *      trying to switch pages/locking vs unlocking the page
+ * @param[in] i_lockMutex - bool to inform call chain whether we want
+ *              to actually lock the page mutex or not. When false,
+ *              the function assumes the appropriate mutex has already
+ *              been locked and skips the call to mutex_lock
+ * @param[in/out] i_pageLocked - bool to tell the caller if the page
+ *      was successfully locked.
+ * @param[in] i_desiredPage - The page we want to switch to
+ * @param[in] i_args - This is an argument list for the device driver
+ *      framework.  This argument list consists of the chip number of
+ *      the EEPROM to access from the given I2C Master target and the
+ *      internal offset to use on the slave I2C device.
+ *
+ * @return errlHndl_t - NULL if successful, otherwise a pointer to the
+ *      error log.
+ */
+errlHndl_t eepromPageOp( TARGETING::Target * i_target,
+                         bool i_switchPage,
+                         bool i_lockMutex,
+                         bool & io_pageLocked,
+                         uint8_t i_desiredPage,
+                         eeprom_addr_t i_i2cInfo );
+
+
+/*
+ * @brief This utility function determines if a read/write straddles
+ *        the boundary between EEPROM pages and if so, returns the
+ *        parameters to perform 2 operations, one for each page.
+ *
+ * @param[in] i_originalOffset - The requested read/write offset into
+ *          the EEPROM.
+ * @param[in] i_originalLen - The requested length of the data.
+ * @param[in/out] io_newLen - The length of the data to retrieve
+ * @param[out] o_pageTwoBuflen - The length of data requested that
+ *          crossed over into the second EEPROM page.
+ * @param[in] i_i2cInfo - Structure of I2C parameters needed to determine
+ *             if we run the body of this function.
+
+ * @return bool - True if the requested data straddles the EEPROM page
+ *          boundary, False otherwise. If False, io_newLen == i_originalLen.
+ */
+bool crossesEepromPageBoundary( uint64_t i_originalOffset,
+                                 size_t i_originalLen,
+                                 size_t & io_newLen,
+                                 size_t & o_pageTwoBuflen,
+                                 eeprom_addr_t i_i2cInfo );
+
+
+/**
  * @brief This function peforms the sequencing to do a read of the
  *      EEPROM that is identified.
  *
@@ -130,6 +193,37 @@ errlHndl_t eepromRead ( TARGETING::Target * i_target,
                         size_t i_buflen,
                         eeprom_addr_t i_i2cInfo );
 
+
+/**
+ * @brief This function actually performs the i2c operations to read data from
+ *        the EEPROM
+ *
+ * @param[in] i_target - Target device
+ *
+ * @param[out] o_buffer - the buffer that will return the data read from
+ *                    the eeprom device
+ *
+ * @param[in] i_buflen - Number of bytes read from the EEPROM device
+ *
+ * @param[in] i_byteAddress - the offset into the EEPROM device
+ *
+ * @param[in] i_byteAddressSize - the size of the byte address (1 or 2 bytes)
+ *
+ * @param[in] i_i2cInfo - Structure of I2C parameters needed to execute the
+ *      command to the I2C device driver
+ *
+ * @return errlHndl_t - NULL if successful, otherwise a pointer to the
+ *       error log.
+ */
+errlHndl_t eepromReadData( TARGETING::Target * i_target,
+                           void * o_buffer,
+                           size_t i_buflen,
+                           void * i_byteAddress,
+                           size_t i_byteAddressSize,
+                           eeprom_addr_t i_i2cInfo );
+
+
+
 /**
  * @brief This function peforms the sequencing to do a write of the
  *      EEPROM that is identified.
@@ -155,25 +249,52 @@ errlHndl_t eepromWrite ( TARGETING::Target * i_target,
                          size_t & io_buflen,
                          eeprom_addr_t i_i2cInfo );
 
+
+
+/**
+ * @brief This function actually writes data into the devices EEPROM
+ *
+ * @param[in] i_target - Target device.
+ * @param[in] i_dataToWrite - The data to be written into the device.
+ * @param[in] i_dataLen - The length of the data to be written.
+ * @param[in] i_byteAddress - the offset into the devices EEPROM.
+ * @param[in] i_byteAddressSize - the size of byte address varable.
+ * @param[in] i_i2cInfo - Structure of I2C parameters needed to execute
+ *      the command to the I2C device driver.
+ */
+errlHndl_t eepromWriteData( TARGETING::Target * i_target,
+                            void * i_dataToWrite,
+                            size_t i_dataLen,
+                            void * i_byteAddress,
+                            size_t i_byteAddressSize,
+                            eeprom_addr_t i_i2cInfo );
+
+
 /**
  * @brief This function prepares the I2C byte address for adding to the
  *      existing buffer (for Writes), or as a separate write operation
  *      (for Reads).
  *
+ * @param[in] i_target - the target to prepare the addressing for.
+ *
  * @param[in/out] io_buffer - The buffer to be written as a byte address to
  *      the EEPROM device.  Must be pre-allocated to MAX_BYTE_ADDR size.
  *
  * @param[out] o_bufSize - The size of the buffer to be written.
  *
+ * @param[out] o_desiredPage - The page we want to switch to.
+ *
  * @param[in] i_i2cInfo - Structure of I2C parameters needed to execute
  *      the command to the I2C device driver.
  *
  * @return errlHndl_t - NULL if successful, otherwise a pointer to the
  *      error log.
  */
-errlHndl_t eepromPrepareAddress ( void * io_buffer,
+errlHndl_t eepromPrepareAddress ( TARGETING::Target * i_target,
+                                  void * io_buffer,
                                   size_t & o_bufSize,
-                                  eeprom_addr_t i_i2cInfo );
+                                  uint8_t & o_desiredPage,
+                                  eeprom_addr_t i_i2cInfo);
 
 /**
  * @brief this function will read all of the associated attributes needed
diff --git a/src/usr/i2c/i2c.C b/src/usr/i2c/i2c.C
index 62a8f15d0..5b9415eb5 100755
--- a/src/usr/i2c/i2c.C
+++ b/src/usr/i2c/i2c.C
@@ -73,9 +73,11 @@ TRAC_INIT( & g_trac_i2cr, "I2CR", KILOBYTE );
 // Defines
 // ----------------------------------------------
 #define I2C_RESET_DELAY_NS (5 * NS_PER_MSEC)  // Sleep for 5 ms after reset
-#define P8_MASTER_ENGINES 2         // Number of Engines used in P8
-#define P8_MASTER_PORTS 3           // Number of Ports used in P8
-#define CENTAUR_MASTER_ENGINES 1    // Number of Engines in a Centaur
+#define P8_MASTER_ENGINES 2        // Number of Engines used in P8
+#define P8_MASTER_PORTS 3          // Number of Ports used in P8
+#define CENTAUR_MASTER_ENGINES 1   // Number of Engines in a Centaur
+#define MAX_NACK_RETRIES 3
+#define PAGE_OPERATION 0xffffffff  // Special value use to determine type of op
 
 // Derived from ATTR_I2C_BUS_SPEED_ARRAY[engine][port] attribute
 const TARGETING::ATTR_I2C_BUS_SPEED_ARRAY_type g_var = {{NULL}};
@@ -123,13 +125,6 @@ errlHndl_t i2cPerformOp( DeviceFW::OperationType i_opType,
     // These are additional parms in the case an offset is passed in
     // via va_list, as well
 
-    args.offset_length = va_arg( i_args, uint64_t);
-
-    if ( args.offset_length != 0 )
-    {
-        args.offset_buffer = reinterpret_cast<uint8_t*>
-                                             (va_arg(i_args, uint64_t));
-    }
 
     // Set both Host and FSI switches to 0 so that they get set later by
     // attribute in i2cCommonOp()
@@ -137,16 +132,90 @@ errlHndl_t i2cPerformOp( DeviceFW::OperationType i_opType,
     args.switches.useFsiI2C  = 0;
 
 
-    // Call common function
-    err = i2cCommonOp( i_opType,
-                       i_target,
-                       io_buffer,
-                       io_buflen,
-                       i_accessType,
-                       args );
+    // Decide if page select was requested (denoted with special device address)
+    if( args.devAddr == PAGE_OPERATION )
+    {
 
+        // since this was a page operation, next arg will be whether we want to
+        // lock the page, or unlock
+        bool l_lockOp = static_cast<bool>(va_arg(i_args, int));
+        if(l_lockOp)
+        {
+            //If page select requested, desired page would be passed in va_list
+            uint8_t l_desiredPage = static_cast<uint8_t>(va_arg(i_args, int ));
 
-    TRACDCOMP( g_trac_i2c,
+            bool l_lockMutex = static_cast<bool>(va_arg(i_args, int));
+            err = i2cPageSwitchOp( i_opType,
+                                    i_target,
+                                    i_accessType,
+                                    l_desiredPage,
+                                    l_lockMutex,
+                                    args );
+
+
+            if( err )
+            {
+                TRACFCOMP(g_trac_i2c, "Locking the page FAILED");
+                bool l_pageUnlockSuccess = false;
+                l_pageUnlockSuccess = i2cPageUnlockOp( i_target,
+                                                    args );
+                if( !l_pageUnlockSuccess )
+                {
+                    TRACFCOMP(g_trac_i2c,
+                        "An Error occurred when unlocking page after"
+                        " failure to lock the page!");
+                }
+            }
+        }
+        else
+        {
+            bool l_pageUnlockSuccess;
+            l_pageUnlockSuccess = i2cPageUnlockOp( i_target,
+                                                   args );
+            if( !l_pageUnlockSuccess )
+            {
+                TRACFCOMP(g_trac_i2c,"i2cPerformOp::i2cPageUnlockOp - Failure unlocking the page");
+                /*@
+                 * @errortype
+                 * @reasoncode      I2C_FAILURE_UNLOCKING_EEPROM_PAGE
+                 * @severity        ERRORLOG_SEV_UNRECOVERABLE
+                 * @moduleid        I2C_PERFORM_OP
+                 * @userdata1       Target Huid
+                 * @userdata2       <UNUSED>
+                 * @devdesc         I2C master encountered an error while
+                 *                  trying to unlock the eepromPage
+                 */
+                err = new ERRORLOG::ErrlEntry( ERRORLOG::ERRL_SEV_UNRECOVERABLE,
+                                               I2C_PERFORM_OP,
+                                               I2C_FAILURE_UNLOCKING_EEPROM_PAGE,
+                                               TARGETING::get_huid(i_target),
+                                               0x0,
+                                               true /*Add HB SW Callout*/ );
+                // TODO RTC 148705: Callout downstream DIMMs
+                err->collectTrace(I2C_COMP_NAME, 256 );
+            }
+        }
+
+    }
+    else
+    {
+        args.offset_length = va_arg( i_args, uint64_t);
+        if ( args.offset_length != 0 )
+        {
+            args.offset_buffer = reinterpret_cast<uint8_t*>
+                                                 (va_arg(i_args, uint64_t));
+        }
+            // Else, call the normal common function
+            err = i2cCommonOp( i_opType,
+                               i_target,
+                               io_buffer,
+                               io_buflen,
+                               i_accessType,
+                               args );
+    }
+
+
+    TRACUCOMP( g_trac_i2c,
                EXIT_MRK"i2cPerformOp() - %s",
                ((NULL == err) ? "No Error" : "With Error") );
 
@@ -283,6 +352,365 @@ errlHndl_t fsi_i2cPerformOp( DeviceFW::OperationType i_opType,
     return err;
 } // end fsi_i2cPerformOp
 
+
+// ------------------------------------------------------------------
+// i2cHandleError
+// ------------------------------------------------------------------
+void i2cHandleError( TARGETING::Target * i_target,
+                     errlHndl_t & i_err,
+                     misc_args_t & i_args )
+{
+    errlHndl_t err_reset = NULL;
+    TRACUCOMP(g_trac_i2c, ENTER_MRK"i2cHandlError()");
+    if( i_err )
+    {
+        // if it was a bus arbitration lost error set the
+        // the reset level so a force unlock reset can be performed
+        i2c_reset_level l_reset_level = BASIC_RESET;
+
+        if ( i_err->reasonCode() == I2C_ARBITRATION_LOST_ONLY_FOUND )
+        {
+
+            l_reset_level = FORCE_UNLOCK_RESET;
+        }
+
+        // Reset the I2C Master
+        err_reset = i2cReset( i_target,
+                              i_args,
+                              l_reset_level);
+
+        if( err_reset )
+        {
+            // 2 error logs, so commit the reset log here
+            TRACFCOMP( g_trac_i2c, ERR_MRK"i2cCommonOp() - "
+                    "Previous error (rc=0x%X, eid=0x%X) before "
+                    "i2cReset() failed.  Committing reset error "
+                    "(rc=0x%X, eid=0x%X) and returning original error",
+                    i_err->reasonCode(), i_err->eid(),
+                    err_reset->reasonCode(), err_reset->eid() );
+
+            errlCommit( err_reset, I2C_COMP_ID );
+
+       }
+
+        // Sleep to allow devices to recover from reset
+        nanosleep( 0, I2C_RESET_DELAY_NS );
+
+    }
+    TRACUCOMP(g_trac_i2c, EXIT_MRK"i2cHandlError()");
+}
+
+// ------------------------------------------------------------------
+// i2cPageSwitchOp
+// ------------------------------------------------------------------
+errlHndl_t i2cPageSwitchOp( DeviceFW::OperationType i_opType,
+                             TARGETING::Target * i_target,
+                             int64_t i_accessType,
+                             uint8_t i_desiredPage,
+                             bool i_lockMutex,
+                             misc_args_t & i_args )
+{
+    TRACUCOMP(g_trac_i2c, ENTER_MRK"i2cPageSwitchOp");
+
+    errlHndl_t l_err = NULL;
+    errlHndl_t l_err_NACK = NULL;
+    bool l_mutexSuccess = false;
+    bool l_pageSwitchNeeded = false;
+    bool l_mutex_needs_unlock = false;
+
+    bool l_error = false;
+    mutex_t * l_pageLock = NULL;
+
+    do
+    {
+
+        // Check for Master Sentinel chip
+        if( TARGETING::MASTER_PROCESSOR_CHIP_TARGET_SENTINEL == i_target )
+        {
+            TRACFCOMP( g_trac_i2c,
+                       ERR_MRK"i2cPageSwitchOp() - Cannot target Master Sentinel "
+                       "Chip for an I2C Operation!" );
+
+            /*@
+             * @errortype
+             * @reasoncode     I2C_MASTER_SENTINEL_TARGET
+             * @severity       ERRORLOG_SEV_UNRECOVERABLE
+             * @moduleid       I2C_PAGE_LOCK_OP
+             * @userdata1      Operation Type requested
+             * @userdata2      <UNUSED>
+             * @devdesc        Master Sentinel chip was used as a target for an
+             *                 I2C operation.  This is not permitted.
+             */
+            l_err = new ERRORLOG::ErrlEntry( ERRORLOG::ERRL_SEV_UNRECOVERABLE,
+                                           I2C_PERFORM_OP,
+                                           I2C_MASTER_SENTINEL_TARGET,
+                                           i_opType,
+                                           0x0,
+                                           true /*Add HB SW Callout*/ );
+
+            l_err->collectTrace( I2C_COMP_NAME, 256);
+
+            break;
+        }
+
+        //Set Host vs Fsi switches if not done already
+        i2cSetSwitches(i_target, i_args);
+
+
+
+        if(i_lockMutex)
+        {
+            //get page mutex
+            l_mutexSuccess = i2cGetPageMutex(i_target,
+                                           i_args,
+                                           l_pageLock );
+            if(!l_mutexSuccess)
+            {
+                TRACUCOMP(g_trac_i2c,
+                          ERR_MRK"Error in i2cPageSwitchOp::i2cGetPageMutex()");
+                /*@
+                 * @errortype
+                 * @reasoncode     I2C_INVALID_EEPROM_PAGE_MUTEX
+                 * @severity       ERRORLOG_SEV_UNRECOVERABLE
+                 * @moduleid       I2C_PAGE_LOCK_OP
+                 * @userdata1      Target Huid
+                 * @userdata2      <UNUSED>
+                 * @devdesc        There was an error retrieving the EEPROM page
+                 *                 mutex for this i2c master engine
+                 */
+                l_err = new ERRORLOG::ErrlEntry( ERRORLOG::ERRL_SEV_UNRECOVERABLE,
+                                                 I2C_PERFORM_OP,
+                                                 I2C_INVALID_EEPROM_PAGE_MUTEX,
+                                                 TARGETING::get_huid(i_target),
+                                                 0x0,
+                                                 true /*Add HB SW Callout*/ );
+
+                l_err->collectTrace( I2C_COMP_NAME, 256 );
+                break;
+            }
+
+            (void)mutex_lock( l_pageLock );
+        }
+        // Calculate variables related to I2C Bus speed in 'args' struct
+        l_err = i2cSetBusVariables( i_target, I2C_BUS_SPEED_FROM_MRW, i_args);
+
+        if( l_err )
+        {
+            TRACFCOMP(g_trac_i2c,
+                    "Error in i2cPageSwitchOp::i2cSetBusVariables()");
+
+            // Error means we need to unlock the page mutex prematurely
+            l_mutex_needs_unlock = true;
+            // Skip performing actual I2C Operation
+            break;
+        }
+
+
+        // Set device address to switch to appropriate page
+        if( i_desiredPage == PAGE_ONE )
+        {
+            i_args.devAddr = PAGE_ONE_ADDR;
+        }
+        else if( i_desiredPage == PAGE_ZERO )
+        {
+            i_args.devAddr = PAGE_ZERO_ADDR;
+        }
+        l_pageSwitchNeeded = true;
+
+        //TODO: RTC 147385
+        //optimize to remember current page of i2c master device
+
+        if( l_pageSwitchNeeded )
+        {
+            // Perform the actual write operation to switch pages.
+            i_args.read_not_write  = false;
+            i_args.with_stop       = true;
+            i_args.skip_mode_setup = false;
+
+
+            //going to write 2 bytes of zeros to special device address
+            size_t l_zeroBuflen = 2;
+            uint8_t * l_zeroBuffer = static_cast<uint8_t*>(malloc(l_zeroBuflen));
+            memset(l_zeroBuffer, 0, l_zeroBuflen);
+
+
+            TRACUCOMP(g_trac_i2c,"i2cPageSwitchOp args! \n"
+                    "misc_args_t: port:%d / engine: %d: devAddr: %x: skip_mode_step(%d):\n"
+                    "with_stop(%d): read_not_write(%d): bus_speed: %d: bit_rate_divisor: %d:\n"
+                    "polling_interval_ns: %d: timeout_count: %d: offset_length: %d",
+                    i_args.port, i_args.engine, i_args.devAddr, i_args.skip_mode_setup,
+                    i_args.with_stop, i_args.read_not_write, i_args.bus_speed,
+                    i_args.bit_rate_divisor, i_args.polling_interval_ns, i_args.timeout_count,
+                    i_args.offset_length );
+
+
+            // Retry MAX_NACK_RETRIES so we can bypass nacks caused by a busy bus.
+            // Other Nack errors are expected and caused by the empty write
+            // associated with the page switch operation.
+            for(uint8_t retry = 0;
+                retry <= MAX_NACK_RETRIES;
+                retry++)
+            {
+                l_err = i2cWrite(i_target,
+                                 l_zeroBuffer,
+                                 l_zeroBuflen,
+                                 i_args);
+
+                if(l_err == NULL)
+                {
+                    // Operation completed successfully
+                    // set attribute, free memory and break from retry loop
+                    // TODO Set EEPROM_PAGE attribute to save page for
+                    // optimization
+                    TRACUCOMP(g_trac_i2c,"Set EEPROM_PAGE to %d", i_desiredPage);
+                    // i_target->setAttr<TARGETING::ATTR_EEPROM_PAGE>(l_newPage);
+                    free(l_zeroBuffer);
+                    break;
+                }
+                else if( l_err->reasonCode() != I2C_NACK_ONLY_FOUND)
+                {
+                    // Only retry on NACK failures. Break form retry loop
+                    TRACFCOMP(g_trac_i2c,
+                            ERR_MRK"i2cPageSwitchOp(): I2C Write "
+                            "Non-NACK fail %x", i_args.devAddr );
+                    l_err->collectTrace(I2C_COMP_NAME);
+                    l_mutex_needs_unlock = true;
+                    l_error = true;
+                    break;
+                }
+                else // Handle NACK error
+                {
+                    TRACFCOMP(g_trac_i2c,
+                       "i2cPageSwitchOp::Expected Nack error. Retrying in case "
+                       "this nack was caused by bus being busy "
+                       "loop = %d", retry);
+
+                    nanosleep( 0, i_args.polling_interval_ns );
+
+                    // Retry on NACKs just in case the cause was a busy i2c bus.
+                    if( retry < MAX_NACK_RETRIES )
+                    {
+                        if(l_err_NACK == NULL)
+                        {
+                            l_err_NACK = l_err;
+                          //  TRACFCOMP(g_trac_i2c,
+                            //        "Saving first Nack error and retry");
+                            nanosleep(0, i_args.polling_interval_ns);
+                            l_err_NACK->collectTrace(I2C_COMP_NAME);
+
+                        }
+                        else
+                        {
+                            // Delete this new NACK error
+                            delete l_err;
+                            nanosleep(0 ,i_args.polling_interval_ns);
+                            l_err = NULL;
+                        }
+                        // continue to retry
+                        continue;
+                    }
+                    else // no more retries: trace and break;
+                    {
+                        TRACFCOMP(g_trac_i2c,
+                                "Exiting Nack retry loop");
+                        break;
+                    }
+                }
+
+            } // end of retry loop
+
+            if(l_err_NACK)
+            {
+                if( l_err )
+                {
+                    i2cHandleError( i_target,
+                                    l_err,
+                                    i_args );
+                    delete l_err;
+                    l_err = NULL;
+
+                }
+                delete l_err_NACK;
+                l_err_NACK = NULL;
+            }
+        }
+
+        if( l_error )
+        {
+           //call i2cHandleError
+           i2cHandleError( i_target,
+                           l_err,
+                           i_args );
+           break;
+        }
+    }while( 0 );
+    if( l_mutex_needs_unlock )
+    {
+        TRACFCOMP(g_trac_i2c,
+                "Prematurely unlocking page mutex");
+        (void)mutex_unlock(l_pageLock);
+    }
+
+    TRACUCOMP(g_trac_i2c, EXIT_MRK"i2cPageSwitchOp()");
+
+    return l_err;
+}
+
+
+
+// ------------------------------------------------------------------
+// i2cPageUnlockOp
+// ------------------------------------------------------------------
+bool i2cPageUnlockOp( TARGETING::Target * i_target,
+                            misc_args_t & i_args )
+{
+    TRACUCOMP(g_trac_i2c, ENTER_MRK"i2cPageUnlockOp()");
+    bool l_mutexSuccess = false;
+    mutex_t * l_pageLock = NULL;
+    errlHndl_t l_err = NULL;
+
+    do
+    {
+        // Get the mutex for this target
+        l_mutexSuccess = i2cGetPageMutex( i_target,
+                                          i_args,
+                                          l_pageLock );
+
+        if( !l_mutexSuccess )
+        {
+            TRACUCOMP( g_trac_i2c,
+                   ERR_MRK"Error in i2cPageUnlockOp::i2cGetPageMutex()");
+            /*@
+             * @errortype
+             * @reasoncode     I2C_INVALID_EEPROM_PAGE_MUTEX
+             * @severity       ERRORLOG_SEV_UNRECOVERABLE
+             * @moduleid       I2C_PAGE_UNLOCK_OP
+             * @userdata1      Target Huid
+             * @userdata2      <UNUSED>
+             * @devdesc        There was an error retrieving the EEPROM page
+             *                 mutex for this i2c master engine
+             */
+            l_err = new ERRORLOG::ErrlEntry( ERRORLOG::ERRL_SEV_UNRECOVERABLE,
+                                             I2C_PERFORM_OP,
+                                             I2C_INVALID_EEPROM_PAGE_MUTEX,
+                                             TARGETING::get_huid(i_target),
+                                             0x0,
+                                             true /*Add HB SW Callout*/ );
+
+            l_err->collectTrace( I2C_COMP_NAME, 256 );
+            errlCommit(l_err, I2C_COMP_ID);
+            break;
+        }
+        //Unlock the page mutex
+        (void)mutex_unlock(l_pageLock);
+    }while( 0 );
+
+    TRACUCOMP(g_trac_i2c, EXIT_MRK"i2cPageUnlockOp()");
+    return l_mutexSuccess;
+}
+
+
+
 // ------------------------------------------------------------------
 // i2cSetSwitches
 // ------------------------------------------------------------------
@@ -316,22 +744,14 @@ errlHndl_t i2cCommonOp( DeviceFW::OperationType i_opType,
                         misc_args_t & i_args )
 {
     errlHndl_t err = NULL;
-    errlHndl_t err_reset = NULL;
     bool mutex_success = false;
 
     mutex_t * engineLock = NULL;
     bool mutex_needs_unlock = false;
 
-    TRACDCOMP( g_trac_i2c,
-               ENTER_MRK"i2cCommonOp(): i_opType=%d, aType=%d, "
-               "p/e/devAddr= %d/%d/0x%X, len=%d, offset=%d/%p",
-               (uint64_t) i_opType, i_accessType, i_args.port, i_args.engine,
-               i_args.devAddr, io_buflen, i_args.offset_length,
-               i_args.offset_buffer);
-
     TRACUCOMP( g_trac_i2c,
                ENTER_MRK"i2cCommonOp(): i_opType=%d, aType=%d, "
-               "p/e/devAddr= %d/%d/0x%x, len=%d, offset=%d/%p",
+               "p/e/devAddr= %d/%d/0x%x, len=%d, offset=%x/%p",
                (uint64_t) i_opType, i_accessType, i_args.port, i_args.engine,
                i_args.devAddr, io_buflen, i_args.offset_length,
                i_args.offset_buffer);
@@ -370,6 +790,7 @@ errlHndl_t i2cCommonOp( DeviceFW::OperationType i_opType,
         //Set Host vs Fsi switches if not done already
         i2cSetSwitches(i_target, i_args);
 
+
         // Get the mutex for the requested engine
         mutex_success = i2cGetEngineMutex( i_target,
                                        i_args,
@@ -383,14 +804,8 @@ errlHndl_t i2cCommonOp( DeviceFW::OperationType i_opType,
         }
 
         // Lock on this engine
-        TRACUCOMP( g_trac_i2c,
-                   INFO_MRK"Obtaining lock for engine: %d",
-                   i_args.engine );
         (void)mutex_lock( engineLock );
         mutex_needs_unlock = true;
-        TRACUCOMP( g_trac_i2c,
-                   INFO_MRK"Locked on engine: %d",
-                   i_args.engine );
 
 
         // Calculate variables related to I2C Bus Speed in 'args' struct
@@ -413,7 +828,6 @@ errlHndl_t i2cCommonOp( DeviceFW::OperationType i_opType,
         if( i_opType        == DeviceFW::READ &&
             i_args.offset_length != 0 )
         {
-
             // First WRITE offset to device without a stop
             i_args.read_not_write  = false;
             i_args.with_stop       = false;
@@ -447,7 +861,6 @@ errlHndl_t i2cCommonOp( DeviceFW::OperationType i_opType,
         else if( i_opType        == DeviceFW::WRITE &&
                  i_args.offset_length != 0 )
         {
-
             // Add the Offset Information to the start of the data and
             // then send as a single write operation
 
@@ -552,37 +965,9 @@ errlHndl_t i2cCommonOp( DeviceFW::OperationType i_opType,
         // Handle Error from I2C Operation
         if( err )
         {
-
-            // if it was a bus arbition lost error set the
-            // the reset level so a force unlock reset can be performed
-            i2c_reset_level l_reset_level = BASIC_RESET;
-
-            if ( err->reasonCode() == I2C_ARBITRATION_LOST_ONLY_FOUND )
-            {
-                l_reset_level = FORCE_UNLOCK_RESET;
-            }
-
-            // Reset the I2C Master
-            err_reset = i2cReset( i_target,
-                                  i_args,
-                                  l_reset_level);
-
-            if( err_reset )
-            {
-                // 2 error logs, so commit the reset log here
-                TRACFCOMP( g_trac_i2c, ERR_MRK"i2cCommonOp() - "
-                           "Previous error (rc=0x%X, eid=0x%X) before "
-                           "i2cReset() failed.  Committing reset error "
-                           "(rc=0x%X, eid=0x%X) and returning original error",
-                           err->reasonCode(), err->eid(),
-                           err_reset->reasonCode(), err_reset->eid() );
-
-                errlCommit( err_reset, I2C_COMP_ID );
-            }
-
-            // Sleep to allow devices to recover from reset
-            nanosleep( 0, I2C_RESET_DELAY_NS );
-
+            i2cHandleError( i_target,
+                            err,
+                            i_args );
             break;
         }
 
@@ -1066,7 +1451,7 @@ errlHndl_t i2cWrite ( TARGETING::Target * i_target,
     // Define regs we'll be using
     fifo_reg_t fifo;
 
-    TRACDCOMP( g_trac_i2c,
+    TRACUCOMP( g_trac_i2c,
                ENTER_MRK"i2cWrite()" );
 
     TRACSCOMP( g_trac_i2cr,
@@ -1113,7 +1498,7 @@ errlHndl_t i2cWrite ( TARGETING::Target * i_target,
                 break;
             }
 
-            TRACUCOMP( g_trac_i2cr,
+            TRACSCOMP( g_trac_i2cr,
                        "I2C WRITE DATA  : engine %.2X : port %.2X : "
                        "devAddr %.2X : byte %d : %.2X (0x%lx)",
                        i_args.engine, i_args.port, i_args.devAddr,
@@ -1142,7 +1527,7 @@ errlHndl_t i2cWrite ( TARGETING::Target * i_target,
                "I2C WRITE END   : engine %.2X: port %.2X : devAddr %.2X : len %d",
                i_args.engine, i_args.port, i_args.devAddr, io_buflen );
 
-    TRACDCOMP( g_trac_i2c,
+    TRACUCOMP( g_trac_i2c,
                EXIT_MRK"i2cWrite()" );
 
     return err;
@@ -1276,7 +1661,7 @@ bool i2cGetEngineMutex( TARGETING::Target * i_target,
 
             default:
                 TRACFCOMP( g_trac_i2c,
-                           ERR_MRK"Invalid engine for getting Mutex! "
+                           ERR_MRK"i2cGetEngineMutex: Invalid engine for getting Mutex! "
                            "i_args.engine=%d", i_args.engine );
                 success = false;
                 assert(false, "i2c.C: Invalid engine for getting Mutex!"
@@ -1290,6 +1675,47 @@ bool i2cGetEngineMutex( TARGETING::Target * i_target,
     return success;
 }
 
+// ------------------------------------------------------------------
+// i2cGetPageMutex
+// ------------------------------------------------------------------
+bool i2cGetPageMutex( TARGETING::Target * i_target,
+                      misc_args_t & i_args,
+                      mutex_t *& i_pageLock )
+{
+    bool success = true;
+    do
+    {
+        switch( i_args.engine )
+        {
+            case 0:
+                i_pageLock = i_target->
+                    getHbMutexAttr<TARGETING::ATTR_I2C_PAGE_MUTEX_0>();
+                break;
+
+            case 1:
+                i_pageLock = i_target->
+                    getHbMutexAttr<TARGETING::ATTR_I2C_PAGE_MUTEX_1>();
+                break;
+
+            case 2:
+                i_pageLock = i_target->
+                    getHbMutexAttr<TARGETING::ATTR_I2C_PAGE_MUTEX_2>();
+                break;
+
+            default:
+                TRACFCOMP( g_trac_i2c,
+                        ERR_MRK"i2cGetPageMutex: Invalid engine for getting mutex!");
+                success = false;
+                assert(false, "i2c.C: Invalid engine for getting Mutex!"
+                        "i_args.engine=%d", i_args.engine );
+                break;
+
+        };
+
+    }while( 0 );
+    return success;
+}
+
 
 // ------------------------------------------------------------------
 // i2cWaitForCmdComp
@@ -1326,6 +1752,7 @@ errlHndl_t i2cWaitForCmdComp ( TARGETING::Target * i_target,
 
             if( err )
             {
+                TRACFCOMP(g_trac_i2c, "Errored at i2cWaitForCmdComplete::i2cReadStatusReg");
                 break;
             }
 
@@ -1720,6 +2147,9 @@ errlHndl_t i2cWaitForFifoSpace ( TARGETING::Target * i_target,
 
         if( err )
         {
+            TRACFCOMP( g_trac_i2c,
+                    "Errored out at i2cReadStatusReg: statusreg = %016llx",
+                    status.value);
             break;
         }
 
diff --git a/src/usr/i2c/i2c.H b/src/usr/i2c/i2c.H
index f4be4b8fb..05f11d551 100755
--- a/src/usr/i2c/i2c.H
+++ b/src/usr/i2c/i2c.H
@@ -5,7 +5,7 @@
 /*                                                                        */
 /* OpenPOWER HostBoot Project                                             */
 /*                                                                        */
-/* Contributors Listed Below - COPYRIGHT 2011,2015                        */
+/* Contributors Listed Below - COPYRIGHT 2011,2016                        */
 /* [+] International Business Machines Corp.                              */
 /*                                                                        */
 /*                                                                        */
@@ -51,6 +51,18 @@ enum i2c_reset_level
     FORCE_UNLOCK_RESET,
 };
 
+/**
+ * @brief Miscellaneous enums for I2C
+ */
+enum
+{
+    PAGE_ZERO = 0x0,
+    PAGE_ONE = 0x1,
+    PAGE_UNKNOWN = 0x2,
+    PAGE_ZERO_ADDR = 0x6C,
+    PAGE_ONE_ADDR  = 0x6E,
+};
+
 
 /**
  * @brief FIFO size (width) in bytes.  This dictates how many bytes
@@ -520,8 +532,61 @@ errlHndl_t fsi_i2cPerformOp( DeviceFW::OperationType i_opType,
                          int64_t i_accessType,
                          va_list i_args );
 
+
+/**
+ * @brief Analyzes an error handle object and
+ *        performs an i2c reset if necessary
+ *
+ * @param[in] i_target - The target
+ * @param[in] i_err - There error to analyze
+ * @param[in] i_args - miscellaneous arguments
+ *
+ * @return void
+ */
+void i2cHandleError( TARGETING::Target * i_target,
+                     errlHndl_t & i_err,
+                     misc_args_t & i_args );
+
+
+
+/**
+ * @brief Performs the necessary operations and comparisons
+ *        needed to decide what EEPROM page we are on and locks the appropriate
+ *        page control mutexes
+ * @param[in] i_opType - Operation Type - See DeviceFW::OperationType in
+ *                        driverif.H
+ * @param[in] i_target - The target to lock the page for.
+ * @param[in] i_accessType - Access Type - See DeviceFW::AccessType in
+ *                            userif.H
+ * @param[in] i_desiredPage - The EEPROM page that will be switched to.
+ * @param[in] i_lockMutex - True if we want to actually lock the mutex,
+ *            False if we do not want to lock it.
+ * @param[in] i_args - miscellaneous arguments
+ *
+ * @return errlHndl_t - NULL if successful, otherwise a pointer to an error log
+ *
+ */
+errlHndl_t i2cPageSwitchOp( DeviceFW::OperationType i_opType,
+                             TARGETING::Target * i_target,
+                             int64_t i_accessType,
+                             uint8_t i_desiredPage,
+                             bool i_lockMutex,
+                             misc_args_t & i_args );
+/**
+ * @brief Unlocks the page mutex for targets given page attribute
+ *
+ * @param[in] i_target - target to unlock the page for.
+ * @param[in] i_args - miscellaneous arguments
+ *
+ * @return - True on success, False on failure.
+ */
+bool i2cPageUnlockOp( TARGETING::Target * i_target,
+                            misc_args_t & i_args );
+
+
+
 /**
- * @brief This function sets the Host vs FSI switches if the user has not
+ * @brief Sets the Host vs FSI switches if the user has not
  *  already.
  *
  * param[in] i_target - The target device
@@ -536,7 +601,7 @@ void i2cSetSwitches( TARGETING::Target * i_target,
 /**
 *
 * @brief Performs the actual I2C operation.
-*        NOTE:  This function handles the MUTEX used to avoid deadlocks.
+*        NOTE: Handles the MUTEX used to avoid deadlocks.
 *
 * @param[in] i_opType - Operation Type - See DeviceFW::OperationType in
 *       driverif.H
@@ -572,8 +637,7 @@ errlHndl_t i2cCommonOp( DeviceFW::OperationType i_opType,
 
 
 /**
- * @brief This function will do the real work of reading from the I2C
- *      device.
+ * @brief Does the real work of reading from the I2C device.
  *
  * @param[in] i_target - The I2C master to source the read to the slave.
  *
@@ -594,7 +658,7 @@ errlHndl_t i2cRead ( TARGETING::Target * i_target,
                      misc_args_t & i_args);
 
 /**
- * @brief This function will do the real work of writinging to the I2C
+ * @brief Does the real work of writing to the I2C
  *      device.
  *
  * @param[in] i_target - The I2C master to source the write to the slave.
@@ -618,7 +682,7 @@ errlHndl_t i2cWrite ( TARGETING::Target * i_target,
                       misc_args_t & i_args);
 
 /**
- * @brief This function will do the I2C setup of the Address/Command registers
+ * @brief does the I2C setup of the Address/Command registers
  *      before issuing the 'go' on the I2C bus.
  *
  * @param[in] i_target - The I2C master.
@@ -637,14 +701,15 @@ errlHndl_t i2cSetup ( TARGETING::Target * i_target,
 
 
 /**
- * @brief This function gets the appropriate engine mutex for a given target.
+ * @brief Gets the appropriate engine
+ * mutex for a given target.
  *
  * @param[in] i_target - The target to get the mutex for.
  *
  * @param[in] i_args - Structure containing arguments needed to determine
  *                     the correct engine mutex.
  *
- * @param[in/out] i_engineLock - The mutex.
+ * @param[in/out] i_engineLock - The engine mutex.
  *
  * @return bool - True if valid mutex is found, False otherwise.
  */
@@ -652,8 +717,26 @@ bool i2cGetEngineMutex( TARGETING::Target * i_target,
                         misc_args_t & i_args,
                         mutex_t *& i_engineLock );
 
+
+/**
+ * @brief Gets the appropriate page mutex for the given i2c engine
+ *
+ * @param[in] i_target - The target to get the mutex for.
+ * @param[in] i_args - Structure containing arguments needed to determine
+ *                     the correct page mutex.
+ * @param[in/out] i_pageLock - The page mutex.
+ *
+ * @return bool - True if valid mutex is found, False otherwise.
+ */
+bool i2cGetPageMutex( TARGETING::Target * i_target,
+                      misc_args_t & i_args,
+                      mutex_t *& i_pageLock );
+
+
+
+
 /**
- * @brief This function will wait for the command to be complete or
+ * @brief Wait for the command to be complete or
  *      timeout waiting before returning.
  *
  * @param[in] i_target - The I2C master target.
diff --git a/src/usr/ipmi/ipmifruinv.C b/src/usr/ipmi/ipmifruinv.C
index 720b979a1..ab25c8c50 100644
--- a/src/usr/ipmi/ipmifruinv.C
+++ b/src/usr/ipmi/ipmifruinv.C
@@ -473,7 +473,8 @@ errlHndl_t isdimmIpmiFruInv::addVpdData(std::vector<uint8_t> &io_data,
         if (l_errl)
         {
             TRACFCOMP(g_trac_ipmi,"isdimmIpmiFruInv::addVpdData - "
-                      "Error while reading SPD keyword size");
+                      "Error while reading SPD keyword size for keyword 0x%x",
+                      i_keyword);
             break;
         }
 
diff --git a/src/usr/targeting/common/xmltohb/attribute_types.xml b/src/usr/targeting/common/xmltohb/attribute_types.xml
index eae11b5fc..18b068528 100644
--- a/src/usr/targeting/common/xmltohb/attribute_types.xml
+++ b/src/usr/targeting/common/xmltohb/attribute_types.xml
@@ -1547,8 +1547,15 @@
         </field>
         <field>
             <name>byteAddrOffset</name>
-            <description>The number of bytes a device requires to set its
-                         internal address/offset.</description>
+            <description>
+                The number of bytes a device requires to set its
+                internal address/offset. DDR4 DIMMs require a special EEPROM
+                page switching mechanic denoted here by a value of 1
+                0 = Zero Byte Addressing
+                1 = One Byte Addressing with page select
+                2 = Two Byte Addressing
+                3 = OneByte Addressing with no page select
+            </description>
             <type>uint8_t</type>
             <default>0x02</default>
         </field>
diff --git a/src/usr/targeting/common/xmltohb/attribute_types_hb.xml b/src/usr/targeting/common/xmltohb/attribute_types_hb.xml
index df81d962c..22966e518 100644
--- a/src/usr/targeting/common/xmltohb/attribute_types_hb.xml
+++ b/src/usr/targeting/common/xmltohb/attribute_types_hb.xml
@@ -115,6 +115,7 @@
     <hbOnly/>
 </attribute>
 
+
 <!-- For POD Testing -->
 <attribute>
     <id>HB_MUTEX_TEST_LOCK</id>
@@ -130,6 +131,48 @@
 </attribute>
 
 <attribute>
+    <id>I2C_PAGE_MUTEX_0</id>
+    <description>
+        Mutex to protect page select operations for I2C Master engine 0
+    </description>
+    <simpleType>
+        <hbmutex></hbmutex>
+    </simpleType>
+    <persistency>volatile-zeroed</persistency>
+    <readable/>
+    <writeable/>
+    <hbOnly/>
+</attribute>
+
+<attribute>
+    <id>I2C_PAGE_MUTEX_1</id>
+    <description>
+        Mutex to protect page select operations for I2C Master engine 1
+    </description>
+    <simpleType>
+        <hbmutex></hbmutex>
+    </simpleType>
+    <persistency>volatile-zeroed</persistency>
+    <readable/>
+    <writeable/>
+    <hbOnly/>
+</attribute>
+
+<attribute>
+    <id>I2C_PAGE_MUTEX_2</id>
+    <description>
+        Mutex to protect page select operations for I2C Master engine 2
+    </description>
+    <simpleType>
+        <hbmutex></hbmutex>
+    </simpleType>
+    <persistency>volatile-zeroed</persistency>
+    <readable/>
+    <writeable/>
+    <hbOnly/>
+</attribute>
+
+<attribute>
     <id>I2C_ENGINE_MUTEX_0</id>
     <description>Mutex for I2C Master engine 0</description>
     <simpleType>
diff --git a/src/usr/targeting/common/xmltohb/target_types_hb.xml b/src/usr/targeting/common/xmltohb/target_types_hb.xml
index 05a5cdedf..867f290bc 100755
--- a/src/usr/targeting/common/xmltohb/target_types_hb.xml
+++ b/src/usr/targeting/common/xmltohb/target_types_hb.xml
@@ -171,6 +171,14 @@
         <default>0</default>
     </attribute>
     <attribute>
+        <id>I2C_PAGE_MUTEX_0</id>
+        <default>0</default>
+    </attribute>
+    <attribute>
+        <id>I2C_PAGE_MUTEX_1</id>
+        <default>0</default>
+    </attribute>
+    <attribute>
         <id>GPIO_INFO</id>
     </attribute>
     <attribute><id>VPD_SWITCHES</id></attribute>
diff --git a/src/usr/vpd/spd.C b/src/usr/vpd/spd.C
index 6833e94df..b9b5890b7 100644
--- a/src/usr/vpd/spd.C
+++ b/src/usr/vpd/spd.C
@@ -5,7 +5,7 @@
 /*                                                                        */
 /* OpenPOWER HostBoot Project                                             */
 /*                                                                        */
-/* Contributors Listed Below - COPYRIGHT 2013,2015                        */
+/* Contributors Listed Below - COPYRIGHT 2013,2016                        */
 /* [+] Google Inc.                                                        */
 /* [+] International Business Machines Corp.                              */
 /*                                                                        */
@@ -258,8 +258,10 @@ errlHndl_t spdGetKeywordValue ( DeviceFW::OperationType i_opType,
         else
         {
             TRACFCOMP( g_trac_spd,
-                       ERR_MRK"Invalid Basic Memory Type (0x%04x)",
-                       memType );
+                       ERR_MRK"Invalid Basic Memory Type (0x%04x), "
+                       "target huid = 0x%x",
+                       memType,
+                       TARGETING::get_huid(i_target));
 
             /*@
              * @errortype
@@ -481,11 +483,14 @@ errlHndl_t spdFetchData ( uint64_t i_byteAddr,
                                           i_byteAddr ) );
             if( err )
             {
+                TRACFCOMP(g_trac_spd,
+                        "ERROR: failing out of deviceOp in spd.C");
                 break;
             }
         }
         else
         {
+            TRACFCOMP(g_trac_spd, "spdFetchData: vpd source incorrect!: %x", vpdSource);
             configError = true;
         }
 
@@ -2039,18 +2044,29 @@ void setPartAndSerialNumberAttributes( TARGETING::Target * i_target )
         }
 
         // Get the keyword sizes
-        size_t l_partDataSize = 0;
-        size_t l_serialDataSize = 0;
-        if( SPD_DDR3 == l_memType )
+        const KeywordData* entry = NULL;
+        l_err = getKeywordEntry( l_partKeyword,
+                                 l_memType,
+                                 i_target,
+                                 entry );
+        if( l_err )
         {
-            l_partDataSize = ddr3Data[l_partKeyword].length;
-            l_serialDataSize = ddr3Data[l_serialKeyword].length;
+            break;
         }
-        else
+        size_t l_partDataSize = entry->length;
+
+        entry = NULL;
+        l_err = getKeywordEntry( l_serialKeyword,
+                                 l_memType,
+                                 i_target,
+                                 entry );
+        if( l_err )
         {
-            l_partDataSize = ddr4Data[l_partKeyword].length;
-            l_serialDataSize = ddr4Data[l_serialKeyword].length;
+            break;
         }
+        size_t l_serialDataSize = entry->length;
+        TRACDCOMP(g_trac_spd,"l_partDataSize=%d,l_serialDataSize=%d\n",
+                l_partDataSize,l_serialDataSize);
 
         //read the keywords from SEEPROM since PNOR may not be loaded yet
         uint8_t l_partNumberData[l_partDataSize];
@@ -2079,7 +2095,7 @@ void setPartAndSerialNumberAttributes( TARGETING::Target * i_target )
 
         if( l_err )
         {
-            TRACDCOMP(g_trac_spd, ERR_MRK"spd.C::setPartAndSerialNumberAttributes(): Error after spdGetValue-> SERIAL_NUMBER");
+            TRACFCOMP(g_trac_spd, ERR_MRK"spd.C::setPartAndSerialNumberAttributes(): Error after spdGetValue-> SERIAL_NUMBER");
             errlCommit(l_err, VPD_COMP_ID);
             l_err = NULL;
             break;
@@ -2091,8 +2107,9 @@ void setPartAndSerialNumberAttributes( TARGETING::Target * i_target )
         size_t expectedSNSize = sizeof(l_SN);
         if(expectedPNSize < l_partDataSize)
         {
-            TRACFCOMP(g_trac_spd, "Part data size too large for attribute. Expected: %d Actual: %d",
-                        expectedPNSize, l_partDataSize);
+            TRACFCOMP(g_trac_spd, "Part data size too large for attribute. Expected: %d Actual: %d"
+                    "Keyword: %X",
+                    expectedPNSize, l_partDataSize, l_partKeyword);
         }
         else
         {
@@ -2143,16 +2160,18 @@ errlHndl_t cmpPnorToSeeprom ( TARGETING::Target * i_target,
             break;
         }
 
-        // Get the keyword size
-        size_t dataSize = 0;
-        if( SPD_DDR3 == memType )
-        {
-            dataSize = ddr3Data[i_keyword].length;
-        }
-        else
+         // Get the keyword size
+        const KeywordData* entry = NULL;
+        err = getKeywordEntry( i_keyword,
+                                 memType,
+                                 i_target,
+                                 entry );
+        if( err )
         {
-            dataSize = ddr4Data[i_keyword].length;
+            break;
         }
+        size_t dataSize = entry->length;
+
 
         // Read the keyword from PNOR
         size_t sizePnor = dataSize;
@@ -2211,8 +2230,9 @@ errlHndl_t cmpPnorToSeeprom ( TARGETING::Target * i_target,
 errlHndl_t loadPnor ( TARGETING::Target * i_target )
 {
     errlHndl_t err = NULL;
-
-    TRACSSCOMP( g_trac_spd, ENTER_MRK"loadPnorCache()" );
+    size_t writeDataSize = 0;
+    uint8_t spdEepromData[DIMM_SPD_SECTION_SIZE];
+    TRACSSCOMP( g_trac_spd, ENTER_MRK"loadPnor()" );
 
     do
     {
@@ -2225,13 +2245,40 @@ errlHndl_t loadPnor ( TARGETING::Target * i_target )
             break;
         }
 
+        // Determine the memory type so we know if we need to read 256 or
+        // 512 from the eeprom
+        uint8_t memType = 0x0;
+        err = getMemType( memType,
+                          i_target,
+                          VPD::SEEPROM );
+
+        if( err )
+        {
+            TRACFCOMP(g_trac_spd,
+                    "spd.C::loadPnor - Error getting memtype(0x%x) "
+                    "for target = 0x%x",
+                    memType,
+                    TARGETING::get_huid(i_target));
+            break;
+        }
+
         // Load PNOR cache from SEEPROM
+        // Read entire EEPROM at one time
+        if( memType == SPD_DDR3 )
+        {
+            // EEPROM is only 256 bytes
+            writeDataSize = DIMM_SPD_SECTION_SIZE/2;
+        }
+        else if( memType == SPD_DDR4 )
+        {
+            // EEPROM is 512 bytes
+            writeDataSize = DIMM_SPD_SECTION_SIZE;
+        }
 
-        // Read the entire SPD section from SEEPROM
-        uint8_t writeData[DIMM_SPD_SECTION_SIZE];
+        // Fetch the EEPROM daa
         err = spdFetchData ( 0x0,
-                             DIMM_SPD_SECTION_SIZE,
-                             writeData,
+                             writeDataSize,
+                             spdEepromData,
                              i_target,
                              VPD::SEEPROM );
         if( err )
@@ -2240,19 +2287,20 @@ errlHndl_t loadPnor ( TARGETING::Target * i_target )
                 ERR_MRK"loadPnorCache: Error reading SEEPROM SPD data" );
             break;
         }
-
         // Write the entire SPD section to PNOR
+        TRACDBIN(g_trac_spd, "ENTIRE EEPROM", spdEepromData, writeDataSize);
         err = spdWriteData( 0x0,
-                            DIMM_SPD_SECTION_SIZE,
-                            writeData,
+                            writeDataSize,
+                            spdEepromData,
                             i_target,
                             VPD::PNOR );
         if( err )
         {
-            TRACFCOMP( g_trac_spd,ERR_MRK"loadPnorCache: Error writing PNOR SPD data" );
+            TRACFCOMP( g_trac_spd,ERR_MRK"loadPnorCache: Error writing PNOR SPD data 2" );
             break;
         }
 
+
     } while(0);
 
     TRACSSCOMP( g_trac_spd, EXIT_MRK"loadPnorCache()" );
diff --git a/src/usr/vpd/spdDDR4.H b/src/usr/vpd/spdDDR4.H
index a3df6f3f7..d263f9cd4 100755
--- a/src/usr/vpd/spdDDR4.H
+++ b/src/usr/vpd/spdDDR4.H
@@ -5,7 +5,7 @@
 /*                                                                        */
 /* OpenPOWER HostBoot Project                                             */
 /*                                                                        */
-/* Contributors Listed Below - COPYRIGHT 2013,2015                        */
+/* Contributors Listed Below - COPYRIGHT 2013,2016                        */
 /* [+] International Business Machines Corp.                              */
 /*                                                                        */
 /*                                                                        */
@@ -112,6 +112,7 @@ const KeywordData ddr4Data[] =
     { DRAM_MANUFACTURER_ID,             0x15f,  0x02,   0x00,   0x00, true,  false, NA },
     { MANUFACTURER_SPECIFIC_DATA,       0x161,  0x1d,   0x00,   0x00, false, false, NA },
     { DIMM_BAD_DQ_DATA,                 0x180,  0x50,   0x00,   0x00, false, true,  NA },
+    { MODULE_REVISION_CODE,             0x15d,  0x01,   0x00,   0x00, false, false, NA },
     // Normal fields supported on DDR4 only
     { BANK_GROUP_BITS,                  0x04,   0x01,   0xC0,   0x06, false, false, NA },
     { BANK_ADDRESS_BITS_DDR4,           0x04,   0x01,   0x30,   0x04, false, false, NA },
@@ -132,7 +133,6 @@ const KeywordData ddr4Data[] =
     { TRRDS_FINE_OFFSET,                0x77,   0x01,   0x00,   0x00, false, false, NA },
     { TCKMAX_FINE_OFFSET,               0x7c,   0x01,   0x00,   0x00, false, false, NA },
     { BASE_CONFIG_CRC,                  0x7f,   0x02,   0x00,   0x00, true,  false, NA },
-    { MODULE_REVISION_CODE_DDR4,        0x15d,  0x01,   0x00,   0x00, false, false, NA },
     { DRAM_STEPPING,                    0x160,  0x01,   0x00,   0x00, false, false, NA },
     { MANUFACTURING_SECTION_CRC,        0x17f,  0x02,   0x00,   0x00, true,  false, NA },
     // Module Specific fields supported on both DDR3 and DDR4