pnor: Fall back to AST mbox transport if IPMI is unavailable

Avoid a flag-day transition by allowing for old BMC releases. Eventually
support for the AST mailbox will be removed and the indirection with it.

Change-Id: Ic62ee6a0f2132583cba290098a52417d32eb772d
Signed-off-by: Andrew Jeffery <andrewrj@au1.ibm.com>
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/66122
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins OP HW <op-hw-jenkins+hostboot@us.ibm.com>
Tested-by: FSP CI Jenkins <fsp-CI-jenkins+hostboot@us.ibm.com>
Reviewed-by: Daniel M. Crowell <dcrowell@us.ibm.com>

10 files changed, 513 insertions, 453 deletions

diff --git a/src/usr/pnor/makefile b/src/usr/pnor/makefile
index ceac32acb..d6b257321 100644
--- a/src/usr/pnor/makefile
+++ b/src/usr/pnor/makefile
@@ -25,15 +25,15 @@
 # IBM_PROLOG_END_TAG
 ROOTPATH = ../../..
 
+HIOMAP_DEPS = ast_mboxdd.o pnor_mboxdd.o pnor_ipmidd.o pnor_hiomapdd.o
 
 MODULE = pnor
 OBJS += pnor_utils.o
 OBJS += pnorrp.o
 OBJS += $(if $(CONFIG_SECUREBOOT),spnorrp.o)
 OBJS += $(if $(CONFIG_PNORDD_IS_SFC),pnor_sfcdd.o)
-OBJS += $(if $(CONFIG_PNORDD_IS_BMCMBOX),ast_mboxdd.o)
-OBJS += $(if $(CONFIG_PNORDD_IS_BMCMBOX),pnor_mboxdd.o)
-OBJS += $(if $(CONFIG_PNORDD_IS_IPMI),pnor_ipmidd.o)
+OBJS += $(if $(CONFIG_PNORDD_IS_BMCMBOX),$(HIOMAP_DEPS))
+OBJS += $(if $(CONFIG_PNORDD_IS_IPMI),$(HIOMAP_DEPS))
 OBJS += pnor_common.o
 OBJS += pnorvalid.o
 OBJS += ecc.o
diff --git a/src/usr/pnor/pnor_hiomapdd.C b/src/usr/pnor/pnor_hiomapdd.C
new file mode 100644
index 000000000..5f998fca1
--- /dev/null
+++ b/src/usr/pnor/pnor_hiomapdd.C
@@ -0,0 +1,260 @@
+/* IBM_PROLOG_BEGIN_TAG                                                   */
+/* This is an automatically generated prolog.                             */
+/*                                                                        */
+/* $Source: src/usr/pnor/pnor_hiomapdd.C $                                */
+/*                                                                        */
+/* OpenPOWER HostBoot Project                                             */
+/*                                                                        */
+/* Contributors Listed Below - COPYRIGHT 2011,2018                        */
+/* [+] International Business Machines Corp.                              */
+/*                                                                        */
+/*                                                                        */
+/* Licensed under the Apache License, Version 2.0 (the "License");        */
+/* you may not use this file except in compliance with the License.       */
+/* You may obtain a copy of the License at                                */
+/*                                                                        */
+/*     http://www.apache.org/licenses/LICENSE-2.0                         */
+/*                                                                        */
+/* Unless required by applicable law or agreed to in writing, software    */
+/* distributed under the License is distributed on an "AS IS" BASIS,      */
+/* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or        */
+/* implied. See the License for the specific language governing           */
+/* permissions and limitations under the License.                         */
+/*                                                                        */
+/* IBM_PROLOG_END_TAG                                                     */
+
+/*****************************************************************************/
+// I n c l u d e s
+/*****************************************************************************/
+#include <console/consoleif.H>
+#include <devicefw/driverif.H>
+#include <initservice/initserviceif.H>
+#include <pnor/pnor_reasoncodes.H>
+#include "pnor_ipmidd.H"
+#include "pnor_mboxdd.H"
+#include "pnor_hiomapdd.H"
+#include "pnor_utils.H"
+
+namespace PNOR
+{
+
+/**
+ * @brief Performs an PNOR Read Operation
+ * This function performs a PNOR Read operation. It follows a pre-defined
+ * prototype functions in order to be registered with the device-driver
+ * framework.
+ *
+ * @param[in]   i_opType        Operation type, see DeviceFW::OperationType
+ *                              in driverif.H
+ * @param[in]   i_target        PNOR target
+ * @param[in/out] io_buffer     Read: Pointer to output data storage
+ *                              Write: Pointer to input data storage
+ * @param[in/out] io_buflen     Input: size of io_buffer (in bytes)
+ *                              Output:
+ *                                  Read: Size of output data
+ *                                  Write: Size of data written
+ * @param[in]   i_accessType    DeviceFW::AccessType enum (usrif.H)
+ * @param[in]   i_args          This is an argument list for DD framework.
+ *                              In this function, there's only one argument,
+ *                              containing the PNOR address and chip select
+ * @return  errlHndl_t
+ */
+errlHndl_t ddRead(DeviceFW::OperationType i_opType,
+                  TARGETING::Target* i_target,
+                  void* io_buffer,
+                  size_t& io_buflen,
+                  int64_t i_accessType,
+                  va_list i_args)
+{
+    errlHndl_t l_err = NULL;
+    uint64_t l_addr = va_arg(i_args, uint64_t);
+
+    do
+    {
+        //@todo (RTC:36951) - add support for unaligned data
+        // Ensure we are operating on a 32-bit (4-byte) boundary
+        assert( reinterpret_cast<uint64_t>(io_buffer) % 4 == 0 );
+        assert( io_buflen % 4 == 0 );
+
+        // The PNOR device driver interface is initialized with the
+        // MASTER_PROCESSOR_CHIP_TARGET_SENTINEL.  Other target
+        // access requires a separate PnorHiomapDD class created
+        assert( i_target == TARGETING::MASTER_PROCESSOR_CHIP_TARGET_SENTINEL );
+
+        // Read the flash
+        l_err = Singleton<PnorHiomapDD>::instance().readFlash(io_buffer,
+                io_buflen,
+                l_addr);
+
+        if(l_err)
+        {
+            break;
+        }
+
+    }
+    while(0);
+
+    return l_err;
+}
+
+/**
+ * @brief Performs an PNOR Write Operation
+ * This function performs a PNOR Write operation. It follows a pre-defined
+ * prototype functions in order to be registered with the device-driver
+ * framework.
+ *
+ * @param[in]   i_opType        Operation type, see DeviceFW::OperationType
+ *                              in driverif.H
+ * @param[in]   i_target        PNOR target
+ * @param[in/out] io_buffer     Read: Pointer to output data storage
+ *                              Write: Pointer to input data storage
+ * @param[in/out] io_buflen     Input: size of io_buffer (in bytes)
+ *                              Output:
+ *                                  Read: Size of output data
+ *                                  Write: Size of data written
+ * @param[in]   i_accessType    DeviceFW::AccessType enum (usrif.H)
+ * @param[in]   i_args          This is an argument list for DD framework.
+ *                              In this function, there's only one argument,
+ *                              containing the PNOR address and chip select
+ * @return  errlHndl_t
+ */
+errlHndl_t ddWrite(DeviceFW::OperationType i_opType,
+                   TARGETING::Target* i_target,
+                   void* io_buffer,
+                   size_t& io_buflen,
+                   int64_t i_accessType,
+                   va_list i_args)
+{
+    errlHndl_t l_err = NULL;
+    uint64_t l_addr = va_arg(i_args, uint64_t);
+
+    do
+    {
+        //@todo (RTC:36951) - add support for unaligned data
+        // Ensure we are operating on a 32-bit (4-byte) boundary
+        assert( reinterpret_cast<uint64_t>(io_buffer) % 4 == 0 );
+        assert( io_buflen % 4 == 0 );
+
+        // The PNOR device driver interface is initialized with the
+        // MASTER_PROCESSOR_CHIP_TARGET_SENTINEL.  Other target
+        // access requires a separate PnorHiomapDD class created
+        assert( i_target == TARGETING::MASTER_PROCESSOR_CHIP_TARGET_SENTINEL );
+
+        // Write the flash
+        l_err = Singleton<PnorHiomapDD>::instance().writeFlash(io_buffer,
+                io_buflen,
+                l_addr);
+
+        if(l_err)
+        {
+            break;
+        }
+
+    }
+    while(0);
+
+    return l_err;
+}
+
+/**
+ * @brief Informs caller if the driver is using
+ *        L3 Cache for fake PNOR or not.
+ *
+ * @return Indicate state of fake PNOR
+ *         true = PNOR DD is using L3 Cache for fake PNOR
+ *         false = PNOR DD not using L3 Cache for fake PNOR
+ */
+bool usingL3Cache()
+{
+    return false;
+}
+
+/**
+ * @brief Retrieve some information about the PNOR/SFC hardware
+ */
+void getPnorInfo( PnorInfo_t& o_pnorInfo )
+{
+    o_pnorInfo.mmioOffset = LPC_SFC_MMIO_OFFSET | LPC_FW_SPACE;
+    o_pnorInfo.norWorkarounds =
+        Singleton<PnorHiomapDD>::instance().getNorWorkarounds();
+    o_pnorInfo.flashSize =
+        Singleton<PnorHiomapDD>::instance().getNorSize();
+}
+
+// Register access functions to DD framework
+DEVICE_REGISTER_ROUTE(DeviceFW::READ,
+                      DeviceFW::PNOR,
+                      TARGETING::TYPE_PROC,
+                      ddRead);
+
+DEVICE_REGISTER_ROUTE(DeviceFW::WRITE,
+                      DeviceFW::PNOR,
+                      TARGETING::TYPE_PROC,
+                      ddWrite);
+
+}; //namespace PNOR
+
+errlHndl_t PnorHiomapDD::readFlash(void* o_buffer,
+                    size_t& io_buflen,
+                    uint64_t i_address)
+{
+    return iv_pnor->readFlash(o_buffer, io_buflen, i_address);
+}
+
+errlHndl_t PnorHiomapDD::writeFlash(const void* i_buffer,
+                     size_t& io_buflen,
+                     uint64_t i_address)
+{
+    return iv_pnor->writeFlash(i_buffer, io_buflen, i_address);
+}
+
+uint32_t PnorHiomapDD::getNorSize(void)
+{
+    return iv_pnor->getNorSize();
+}
+
+uint32_t PnorHiomapDD::getNorWorkarounds(void)
+{
+    return iv_pnor->getNorWorkarounds();
+}
+
+static PnorIf* probeHiomapTransport(TARGETING::Target* i_target)
+{
+    PnorIf* pnor;
+
+    do {
+        if ((pnor = PnorIpmiDD::probe(i_target)))
+        {
+            break;
+        }
+
+        if ((pnor = PnorMboxDD::probe(i_target)))
+        {
+            break;
+        }
+    } while (0);
+
+    if (pnor)
+    {
+        return pnor;
+    }
+
+    CONSOLE::displayf(NULL, "Probes for MBOX and IPMI HIOMAP transports failed\n");
+    CONSOLE::displayf(NULL, "Cannot access PNOR!\n");
+    CONSOLE::flush();
+    INITSERVICE::doShutdown(PNOR::RC_PNOR_INIT_FAILURE);
+
+    assert(false && "Unreachable");
+
+    return NULL;
+}
+
+PnorHiomapDD::PnorHiomapDD(TARGETING::Target* i_target)
+{
+    iv_pnor = probeHiomapTransport(i_target);
+}
+
+PnorHiomapDD::~PnorHiomapDD()
+{
+    delete iv_pnor;
+}
diff --git a/src/usr/pnor/pnor_hiomapdd.H b/src/usr/pnor/pnor_hiomapdd.H
new file mode 100644
index 000000000..8bda811d5
--- /dev/null
+++ b/src/usr/pnor/pnor_hiomapdd.H
@@ -0,0 +1,68 @@
+/* IBM_PROLOG_BEGIN_TAG                                                   */
+/* This is an automatically generated prolog.                             */
+/*                                                                        */
+/* $Source: src/usr/pnor/pnor_hiomapdd.H $                                */
+/*                                                                        */
+/* OpenPOWER HostBoot Project                                             */
+/*                                                                        */
+/* Contributors Listed Below - COPYRIGHT 2018                             */
+/* [+] International Business Machines Corp.                              */
+/*                                                                        */
+/*                                                                        */
+/* Licensed under the Apache License, Version 2.0 (the "License");        */
+/* you may not use this file except in compliance with the License.       */
+/* You may obtain a copy of the License at                                */
+/*                                                                        */
+/*     http://www.apache.org/licenses/LICENSE-2.0                         */
+/*                                                                        */
+/* Unless required by applicable law or agreed to in writing, software    */
+/* distributed under the License is distributed on an "AS IS" BASIS,      */
+/* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or        */
+/* implied. See the License for the specific language governing           */
+/* permissions and limitations under the License.                         */
+/*                                                                        */
+/* IBM_PROLOG_END_TAG                                                     */
+#ifndef __PNOR_HIOMAPDD_H
+#define __PNOR_HIOMAPDD_H
+
+/*
+ * The PnorHiomapDD class implements fallback semantics for the HIOMAP
+ * transport implementations (currently, AST mailbox and IPMI). The constructor
+ * probes each transport, preferring IPMI over the mailbox. If a transport's
+ * probe is successful the instance of the transport's class is stored in
+ * the iv_pnor member of PnorHiomapDD.
+ *
+ * With this in place, we register the readFlash() and writeFlash() methods
+ * of PnorHiomapDD as the handlers for the PNOR device driver route. Each
+ * method then delegates to the respective method on the instance of the class
+ * of transport that was successfully probed.
+ */
+
+#include <errl/errlentry.H>
+#include <targeting/common/target.H>
+
+#include "pnorif.H"
+
+class PnorHiomapDD : public PnorIf
+{
+    public:
+        PnorHiomapDD(TARGETING::Target* i_target = NULL);
+        ~PnorHiomapDD();
+
+        virtual errlHndl_t readFlash(void* o_buffer,
+                                     size_t& io_buflen,
+                                     uint64_t i_address);
+
+        virtual errlHndl_t writeFlash(const void* i_buffer,
+                                      size_t& io_buflen,
+                                      uint64_t i_address);
+
+        virtual uint32_t getNorSize(void);
+
+        virtual uint32_t getNorWorkarounds(void);
+
+    private:
+        PnorIf* iv_pnor;
+};
+
+#endif
diff --git a/src/usr/pnor/pnor_ipmidd.C b/src/usr/pnor/pnor_ipmidd.C
index 6d68e593b..078195dad 100644
--- a/src/usr/pnor/pnor_ipmidd.C
+++ b/src/usr/pnor/pnor_ipmidd.C
@@ -93,170 +93,6 @@ enum {
 // Initialized in pnorrp.C
 extern trace_desc_t* g_trac_pnor;
 
-namespace PNOR
-{
-
-/**
- * @brief Performs an PNOR Read Operation
- * This function performs a PNOR Read operation. It follows a pre-defined
- * prototype functions in order to be registered with the device-driver
- * framework.
- *
- * @param[in]   i_opType        Operation type, see DeviceFW::OperationType
- *                              in driverif.H
- * @param[in]   i_target        PNOR target
- * @param[in/out] io_buffer     Read: Pointer to output data storage
- *                              Write: Pointer to input data storage
- * @param[in/out] io_buflen     Input: size of io_buffer (in bytes)
- *                              Output:
- *                                  Read: Size of output data
- *                                  Write: Size of data written
- * @param[in]   i_accessType    DeviceFW::AccessType enum (usrif.H)
- * @param[in]   i_args          This is an argument list for DD framework.
- *                              In this function, there's only one argument,
- *                              containing the PNOR address and chip select
- * @return  errlHndl_t
- */
-errlHndl_t ddRead(DeviceFW::OperationType i_opType,
-                  TARGETING::Target* i_target,
-                  void* io_buffer,
-                  size_t& io_buflen,
-                  int64_t i_accessType,
-                  va_list i_args)
-{
-    errlHndl_t l_err = NULL;
-    uint64_t l_addr = va_arg(i_args, uint64_t);
-
-    do
-    {
-        //@todo (RTC:36951) - add support for unaligned data
-        // Ensure we are operating on a 32-bit (4-byte) boundary
-        assert( reinterpret_cast<uint64_t>(io_buffer) % 4 == 0 );
-        assert( io_buflen % 4 == 0 );
-
-        // The PNOR device driver interface is initialized with the
-        // MASTER_PROCESSOR_CHIP_TARGET_SENTINEL.  Other target
-        // access requires a separate PnorIpmiDD class created
-        assert( i_target == TARGETING::MASTER_PROCESSOR_CHIP_TARGET_SENTINEL );
-
-        // Read the flash
-        l_err = Singleton<PnorIpmiDD>::instance().readFlash(io_buffer,
-                io_buflen,
-                l_addr);
-
-        if(l_err)
-        {
-            break;
-        }
-
-    }
-    while(0);
-
-    return l_err;
-}
-
-/**
- * @brief Performs an PNOR Write Operation
- * This function performs a PNOR Write operation. It follows a pre-defined
- * prototype functions in order to be registered with the device-driver
- * framework.
- *
- * @param[in]   i_opType        Operation type, see DeviceFW::OperationType
- *                              in driverif.H
- * @param[in]   i_target        PNOR target
- * @param[in/out] io_buffer     Read: Pointer to output data storage
- *                              Write: Pointer to input data storage
- * @param[in/out] io_buflen     Input: size of io_buffer (in bytes)
- *                              Output:
- *                                  Read: Size of output data
- *                                  Write: Size of data written
- * @param[in]   i_accessType    DeviceFW::AccessType enum (usrif.H)
- * @param[in]   i_args          This is an argument list for DD framework.
- *                              In this function, there's only one argument,
- *                              containing the PNOR address and chip select
- * @return  errlHndl_t
- */
-errlHndl_t ddWrite(DeviceFW::OperationType i_opType,
-                   TARGETING::Target* i_target,
-                   void* io_buffer,
-                   size_t& io_buflen,
-                   int64_t i_accessType,
-                   va_list i_args)
-{
-    errlHndl_t l_err = NULL;
-    uint64_t l_addr = va_arg(i_args, uint64_t);
-
-    do
-    {
-        //@todo (RTC:36951) - add support for unaligned data
-        // Ensure we are operating on a 32-bit (4-byte) boundary
-        assert( reinterpret_cast<uint64_t>(io_buffer) % 4 == 0 );
-        assert( io_buflen % 4 == 0 );
-
-        // The PNOR device driver interface is initialized with the
-        // MASTER_PROCESSOR_CHIP_TARGET_SENTINEL.  Other target
-        // access requires a separate PnorIpmiDD class created
-        assert( i_target == TARGETING::MASTER_PROCESSOR_CHIP_TARGET_SENTINEL );
-
-        // Write the flash
-        l_err = Singleton<PnorIpmiDD>::instance().writeFlash(io_buffer,
-                io_buflen,
-                l_addr);
-
-        if(l_err)
-        {
-            break;
-        }
-
-    }
-    while(0);
-
-    return l_err;
-}
-
-/**
- * @brief Informs caller if the driver is using
- *        L3 Cache for fake PNOR or not.
- *
- * @return Indicate state of fake PNOR
- *         true = PNOR DD is using L3 Cache for fake PNOR
- *         false = PNOR DD not using L3 Cache for fake PNOR
- */
-bool usingL3Cache()
-{
-    return false;
-}
-
-/**
- * @brief Retrieve some information about the PNOR/SFC hardware
- */
-void getPnorInfo( PnorInfo_t& o_pnorInfo )
-{
-    o_pnorInfo.mmioOffset = LPC_SFC_MMIO_OFFSET | LPC_FW_SPACE;
-    o_pnorInfo.norWorkarounds =
-        Singleton<PnorIpmiDD>::instance().getNorWorkarounds();
-    o_pnorInfo.flashSize =
-        Singleton<PnorIpmiDD>::instance().getNorSize();
-}
-
-// Register access functions to DD framework
-DEVICE_REGISTER_ROUTE(DeviceFW::READ,
-                      DeviceFW::PNOR,
-                      TARGETING::TYPE_PROC,
-                      ddRead);
-
-DEVICE_REGISTER_ROUTE(DeviceFW::WRITE,
-                      DeviceFW::PNOR,
-                      TARGETING::TYPE_PROC,
-                      ddWrite);
-
-}; //namespace PNOR
-
-
-///////////////////////////////////////////////////////////////////////////////
-///////////////////////////////////////////////////////////////////////////////
-
-
 /**
  * @brief Performs a PNOR Read Operation
  */
@@ -866,3 +702,48 @@ PnorIpmiDD::PnorIpmiDD( TARGETING::Target* i_target )
 PnorIpmiDD::~PnorIpmiDD()
 {
 }
+
+PnorIf* PnorIpmiDD::probe(TARGETING::Target* i_target)
+{
+    errlHndl_t l_err = NULL;
+
+    /*
+     * Test if the daemon is alive by sending an ack message. Make it a no-op
+     * by not setting any flags in the mask argument
+     */
+    HiomapMessage* l_msg = new HiomapMessage(HIOMAP_C_ACK);
+    l_msg->put8(0, 0);
+
+    /* Open-code the exchange to avoid constructing the class for sendCommand */
+    IPMI::completion_code l_cc = IPMI::CC_UNKBAD;
+
+    l_msg->iv_seq = 0;
+
+    uint8_t old_seq = l_msg->iv_seq;
+    uint8_t* l_data = reinterpret_cast <uint8_t*>((char*)l_msg);
+    size_t l_len = 2 + 1; /* Account for command and sequence number */
+    bool success;
+
+    l_err = IPMI::sendrecv(
+                IPMI::pnor_hiomap_request(), l_cc, l_len, l_data);
+    if (!l_err && (l_cc == IPMI::CC_OK))
+    {
+        /* Don't look too closely, storage size doesn't necessarily match */
+        assert(l_len >= 2);
+        l_msg = reinterpret_cast<HiomapMessage *>((char *)l_data);
+        success = (old_seq == l_msg->iv_seq);
+        delete l_msg;
+    }
+    else
+    {
+        success = false;
+    }
+
+    if (success)
+    {
+        TRACFCOMP(g_trac_pnor, "PnorIpmiDD: Detected IPMI HIOMAP transport");
+        return new PnorIpmiDD(i_target);
+    }
+
+    return nullptr;
+}
diff --git a/src/usr/pnor/pnor_ipmidd.H b/src/usr/pnor/pnor_ipmidd.H
index 74ffed7f2..fc843db6a 100644
--- a/src/usr/pnor/pnor_ipmidd.H
+++ b/src/usr/pnor/pnor_ipmidd.H
@@ -33,6 +33,8 @@
 #include <limits.h>
 #include <config.h>
 
+#include "pnorif.H"
+
 namespace PNOR
 {
 class UdPnorDDParms;
@@ -112,59 +114,14 @@ class HiomapMessage
  *  @brief  PNOR Device Driver Class
  *     Provides access to the PNOR flash via the LPC MBOX hardware
  */
-class PnorIpmiDD
+class PnorIpmiDD : public PnorIf
 {
 
     public:
-        /**
-         * @brief Performs a PNOR Read Operation
-         *
-         * @parm o_buffer  Buffer to read data into
-         * @parm io_buflen  Input: Number of bytes to read,
-         *       Output: Number of bytes actually read
-         * @parm i_address  Offset into flash to read
-         *
-         * @return Error from operation
-         */
-        errlHndl_t readFlash(void* o_buffer,
-                             size_t& io_buflen,
-                             uint64_t i_address);
-
-        /**
-         * @brief Performs a PNOR Write Operation
-         *
-         * @parm i_buffer  Buffer to write data from
-         * @parm io_buflen  Input: Number of bytes to write,
-         *       Output: Number of bytes actually written
-         * @parm i_address  Offset into flash to write
-         *
-         * @return Error from operation
-         */
-        errlHndl_t writeFlash(const void* i_buffer,
-                              size_t& io_buflen,
-                              uint64_t i_address);
-
-        /**
-         * @brief Informs caller if PNORDD is using
-         *        L3 Cache for fake PNOR or not.
-         *
-         * @return Indicate state of fake PNOR
-         *         true = PNOR DD is using L3 Cache for fake PNOR
-         *         false = PNOR DD not using L3 Cache for fake PNOR
+        /** @brief Test for the IPMI HIOMAP transport and return an appropriate
+         * PnorDD instance if detected, otherwise nullptr.
          */
-        bool usingL3Cache( );
-
-        /**
-         * @brief Retrieve size of NOR flash
-         * @return Size of PNOR in bytes
-         */
-        uint32_t getNorSize( void );
-
-        /**
-         * @brief Retrieve bitstring of NOR workarounds
-         * @return NOR workarounds (see VendorWorkarounds in norflash.H)
-         */
-        uint32_t getNorWorkarounds( void );
+        static PnorIf* probe(TARGETING::Target* target);
 
         /**
          * @brief Constructor
@@ -173,11 +130,19 @@ class PnorIpmiDD
          *       NOTE: i_target can only be used after targeting is loaded
          */
         PnorIpmiDD( TARGETING::Target* i_target = NULL );
+        virtual ~PnorIpmiDD();
 
-        /**
-         * @brief Destructor
-         */
-        ~PnorIpmiDD();
+        virtual errlHndl_t readFlash(void* o_buffer,
+                                     size_t& io_buflen,
+                                     uint64_t i_address);
+
+        virtual errlHndl_t writeFlash(const void* i_buffer,
+                                      size_t& io_buflen,
+                                      uint64_t i_address);
+
+        virtual uint32_t getNorSize(void);
+
+        virtual uint32_t getNorWorkarounds(void);
 
     protected:
 
diff --git a/src/usr/pnor/pnor_mboxdd.C b/src/usr/pnor/pnor_mboxdd.C
index edb1f4a18..a156ffb8f 100644
--- a/src/usr/pnor/pnor_mboxdd.C
+++ b/src/usr/pnor/pnor_mboxdd.C
@@ -60,172 +60,6 @@
 // Initialized in pnorrp.C
 extern trace_desc_t* g_trac_pnor;
 
-namespace PNOR
-{
-
-/**
- * @brief Performs an PNOR Read Operation
- * This function performs a PNOR Read operation. It follows a pre-defined
- * prototype functions in order to be registered with the device-driver
- * framework.
- *
- * @param[in]   i_opType        Operation type, see DeviceFW::OperationType
- *                              in driverif.H
- * @param[in]   i_target        PNOR target
- * @param[in/out] io_buffer     Read: Pointer to output data storage
- *                              Write: Pointer to input data storage
- * @param[in/out] io_buflen     Input: size of io_buffer (in bytes)
- *                              Output:
- *                                  Read: Size of output data
- *                                  Write: Size of data written
- * @param[in]   i_accessType    DeviceFW::AccessType enum (usrif.H)
- * @param[in]   i_args          This is an argument list for DD framework.
- *                              In this function, there's only one argument,
- *                              containing the PNOR address and chip select
- * @return  errlHndl_t
- */
-errlHndl_t ddRead(DeviceFW::OperationType i_opType,
-                  TARGETING::Target* i_target,
-                  void* io_buffer,
-                  size_t& io_buflen,
-                  int64_t i_accessType,
-                  va_list i_args)
-{
-    errlHndl_t l_err = NULL;
-    uint64_t l_addr = va_arg(i_args, uint64_t);
-
-    do
-    {
-        //@todo (RTC:36951) - add support for unaligned data
-        // Ensure we are operating on a 32-bit (4-byte) boundary
-        assert( reinterpret_cast<uint64_t>(io_buffer) % 4 == 0 );
-        assert( io_buflen % 4 == 0 );
-
-        // The PNOR device driver interface is initialized with the
-        // MASTER_PROCESSOR_CHIP_TARGET_SENTINEL.  Other target
-        // access requires a separate PnorMboxDD class created
-        assert( i_target == TARGETING::MASTER_PROCESSOR_CHIP_TARGET_SENTINEL );
-
-        // Read the flash
-        l_err = Singleton<PnorMboxDD>::instance().readFlash(io_buffer,
-                io_buflen,
-                l_addr);
-
-        if(l_err)
-        {
-            break;
-        }
-
-    }
-    while(0);
-
-    return l_err;
-}
-
-/**
- * @brief Performs an PNOR Write Operation
- * This function performs a PNOR Write operation. It follows a pre-defined
- * prototype functions in order to be registered with the device-driver
- * framework.
- *
- * @param[in]   i_opType        Operation type, see DeviceFW::OperationType
- *                              in driverif.H
- * @param[in]   i_target        PNOR target
- * @param[in/out] io_buffer     Read: Pointer to output data storage
- *                              Write: Pointer to input data storage
- * @param[in/out] io_buflen     Input: size of io_buffer (in bytes)
- *                              Output:
- *                                  Read: Size of output data
- *                                  Write: Size of data written
- * @param[in]   i_accessType    DeviceFW::AccessType enum (usrif.H)
- * @param[in]   i_args          This is an argument list for DD framework.
- *                              In this function, there's only one argument,
- *                              containing the PNOR address and chip select
- * @return  errlHndl_t
- */
-errlHndl_t ddWrite(DeviceFW::OperationType i_opType,
-                   TARGETING::Target* i_target,
-                   void* io_buffer,
-                   size_t& io_buflen,
-                   int64_t i_accessType,
-                   va_list i_args)
-{
-    errlHndl_t l_err = NULL;
-    uint64_t l_addr = va_arg(i_args, uint64_t);
-
-    do
-    {
-        //@todo (RTC:36951) - add support for unaligned data
-        // Ensure we are operating on a 32-bit (4-byte) boundary
-        assert( reinterpret_cast<uint64_t>(io_buffer) % 4 == 0 );
-        assert( io_buflen % 4 == 0 );
-
-        // The PNOR device driver interface is initialized with the
-        // MASTER_PROCESSOR_CHIP_TARGET_SENTINEL.  Other target
-        // access requires a separate PnorMboxDD class created
-        assert( i_target == TARGETING::MASTER_PROCESSOR_CHIP_TARGET_SENTINEL );
-
-        // Write the flash
-        l_err = Singleton<PnorMboxDD>::instance().writeFlash(io_buffer,
-                io_buflen,
-                l_addr);
-
-        if(l_err)
-        {
-            break;
-        }
-
-    }
-    while(0);
-
-    return l_err;
-}
-
-/**
- * @brief Informs caller if the driver is using
- *        L3 Cache for fake PNOR or not.
- *
- * @return Indicate state of fake PNOR
- *         true = PNOR DD is using L3 Cache for fake PNOR
- *         false = PNOR DD not using L3 Cache for fake PNOR
- */
-bool usingL3Cache()
-{
-    return false;
-}
-
-/**
- * @brief Retrieve some information about the PNOR/SFC hardware
- */
-void getPnorInfo( PnorInfo_t& o_pnorInfo )
-{
-    o_pnorInfo.mmioOffset = LPC_SFC_MMIO_OFFSET | LPC_FW_SPACE;
-    o_pnorInfo.norWorkarounds =
-        Singleton<PnorMboxDD>::instance().getNorWorkarounds();
-    o_pnorInfo.flashSize =
-        Singleton<PnorMboxDD>::instance().getNorSize();
-}
-
-
-
-// Register MBOXDD access functions to DD framework
-DEVICE_REGISTER_ROUTE(DeviceFW::READ,
-                      DeviceFW::PNOR,
-                      TARGETING::TYPE_PROC,
-                      ddRead);
-
-DEVICE_REGISTER_ROUTE(DeviceFW::WRITE,
-                      DeviceFW::PNOR,
-                      TARGETING::TYPE_PROC,
-                      ddWrite);
-
-}; //namespace PNOR
-
-
-///////////////////////////////////////////////////////////////////////////////
-///////////////////////////////////////////////////////////////////////////////
-
-
 /**
  * @brief Performs a PNOR Read Operation
  */
@@ -675,3 +509,11 @@ PnorMboxDD::PnorMboxDD( TARGETING::Target* i_target )
 PnorMboxDD::~PnorMboxDD()
 {
 }
+
+PnorIf* PnorMboxDD::probe(TARGETING::Target* i_target)
+{
+    /* If we get so far as to probe mbox, it better be available */
+    TRACFCOMP(g_trac_pnor, "PnorMboxDD: Detected AST mailbox HIOMAP transport");
+
+    return new PnorMboxDD(i_target);
+}
diff --git a/src/usr/pnor/pnor_mboxdd.H b/src/usr/pnor/pnor_mboxdd.H
index 2a10c0695..16105efe2 100644
--- a/src/usr/pnor/pnor_mboxdd.H
+++ b/src/usr/pnor/pnor_mboxdd.H
@@ -27,6 +27,8 @@
 
 #include <limits.h>
 #include <config.h>
+#include "pnorif.H"
+
 namespace PNOR
 {
 class UdPnorDDParms;
@@ -46,59 +48,14 @@ class astMbox;
  *  @brief  PNOR Device Driver Class
  *     Provides access to the PNOR flash via the LPC MBOX hardware
  */
-class PnorMboxDD
+class PnorMboxDD: public PnorIf
 {
 
     public:
-        /**
-         * @brief Performs a PNOR Read Operation
-         *
-         * @parm o_buffer  Buffer to read data into
-         * @parm io_buflen  Input: Number of bytes to read,
-         *       Output: Number of bytes actually read
-         * @parm i_address  Offset into flash to read
-         *
-         * @return Error from operation
+        /** @brief Test for the AST mailbox HIOMAP transport and return an
+         * appropriate PnorDD instance if detected, otherwise nullptr.
          */
-        errlHndl_t readFlash(void* o_buffer,
-                             size_t& io_buflen,
-                             uint64_t i_address);
-
-        /**
-         * @brief Performs a PNOR Write Operation
-         *
-         * @parm i_buffer  Buffer to write data from
-         * @parm io_buflen  Input: Number of bytes to write,
-         *       Output: Number of bytes actually written
-         * @parm i_address  Offset into flash to write
-         *
-         * @return Error from operation
-         */
-        errlHndl_t writeFlash(const void* i_buffer,
-                              size_t& io_buflen,
-                              uint64_t i_address);
-
-        /**
-         * @brief Informs caller if PNORDD is using
-         *        L3 Cache for fake PNOR or not.
-         *
-         * @return Indicate state of fake PNOR
-         *         true = PNOR DD is using L3 Cache for fake PNOR
-         *         false = PNOR DD not using L3 Cache for fake PNOR
-         */
-        bool usingL3Cache( );
-
-        /**
-         * @brief Retrieve size of NOR flash
-         * @return Size of PNOR in bytes
-         */
-        uint32_t getNorSize( void );
-
-        /**
-         * @brief Retrieve bitstring of NOR workarounds
-         * @return NOR workarounds (see VendorWorkarounds in norflash.H)
-         */
-        uint32_t getNorWorkarounds( void );
+        static PnorIf* probe(TARGETING::Target* i_target);
 
         /**
          * @brief Constructor
@@ -111,7 +68,19 @@ class PnorMboxDD
         /**
          * @brief Destructor
          */
-        ~PnorMboxDD();
+        virtual ~PnorMboxDD();
+
+        virtual errlHndl_t readFlash(void* o_buffer,
+                                     size_t& io_buflen,
+                                     uint64_t i_address);
+
+        virtual errlHndl_t writeFlash(const void* i_buffer,
+                                      size_t& io_buflen,
+                                      uint64_t i_address);
+
+        virtual uint32_t getNorSize(void);
+
+        virtual uint32_t getNorWorkarounds(void);
 
     protected:
 
diff --git a/src/usr/pnor/pnorif.H b/src/usr/pnor/pnorif.H
new file mode 100644
index 000000000..598ea2555
--- /dev/null
+++ b/src/usr/pnor/pnorif.H
@@ -0,0 +1,81 @@
+/* IBM_PROLOG_BEGIN_TAG                                                   */
+/* This is an automatically generated prolog.                             */
+/*                                                                        */
+/* $Source: src/usr/pnor/pnorif.H $                                       */
+/*                                                                        */
+/* OpenPOWER HostBoot Project                                             */
+/*                                                                        */
+/* Contributors Listed Below - COPYRIGHT 2011,2018                        */
+/* [+] International Business Machines Corp.                              */
+/*                                                                        */
+/*                                                                        */
+/* Licensed under the Apache License, Version 2.0 (the "License");        */
+/* you may not use this file except in compliance with the License.       */
+/* You may obtain a copy of the License at                                */
+/*                                                                        */
+/*     http://www.apache.org/licenses/LICENSE-2.0                         */
+/*                                                                        */
+/* Unless required by applicable law or agreed to in writing, software    */
+/* distributed under the License is distributed on an "AS IS" BASIS,      */
+/* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or        */
+/* implied. See the License for the specific language governing           */
+/* permissions and limitations under the License.                         */
+/*                                                                        */
+/* IBM_PROLOG_END_TAG                                                     */
+#ifndef __PNORIF_H
+#define __PNORIF_H
+
+#include <errl/errlentry.H>
+
+class PnorIf
+{
+    public:
+        /**
+         * @brief Performs a PNOR Read Operation
+         *
+         * @parm o_buffer  Buffer to read data into
+         * @parm io_buflen  Input: Number of bytes to read,
+         *       Output: Number of bytes actually read
+         * @parm i_address  Offset into flash to read
+         *
+         * @return Error from operation
+         */
+        virtual errlHndl_t readFlash(void* o_buffer,
+                                     size_t& io_buflen,
+                                     uint64_t i_address) = 0;
+
+        /**
+         * @brief Performs a PNOR Write Operation
+         *
+         * @parm i_buffer  Buffer to write data from
+         * @parm io_buflen  Input: Number of bytes to write,
+         *       Output: Number of bytes actually written
+         * @parm i_address  Offset into flash to write
+         *
+         * @return Error from operation
+         */
+        virtual errlHndl_t writeFlash(const void* i_buffer,
+                                      size_t& io_buflen,
+                                      uint64_t i_address) = 0;
+
+        /**
+         * @brief Retrieve size of NOR flash
+         * @return Size of PNOR in bytes
+         */
+        virtual uint32_t getNorSize(void) = 0;
+
+        /**
+         * @brief Retrieve bitstring of NOR workarounds
+         * @return NOR workarounds (see VendorWorkarounds in norflash.H)
+         */
+        virtual uint32_t getNorWorkarounds(void) = 0;
+
+        /**
+         * @brief Destructor
+         */
+        virtual ~PnorIf(void)
+        {
+        }
+};
+
+#endif
diff --git a/src/usr/pnor/pnorvalid.C b/src/usr/pnor/pnorvalid.C
index 342959b05..91b10109f 100644
--- a/src/usr/pnor/pnorvalid.C
+++ b/src/usr/pnor/pnorvalid.C
@@ -47,17 +47,14 @@
 #include <pnor/pnorif.H>
 #include <pnor/pnor_reasoncodes.H>
 #include <lpc/lpcif.H>
-#ifdef CONFIG_PNORDD_IS_SFC
+#if defined(CONFIG_PNORDD_IS_SFC)
 #include "pnor_sfcdd.H"
 using PnorDD = PnorSfcDD;
-#elif CONFIG_PNORDD_IS_BMCMBOX
-#include "pnor_mboxdd.H"
-using PnorDD = PnorMboxDD;
-#elif CONFIG_PNORDD_IS_IPMI
-#include "pnor_ipmidd.H"
-using PnorDD = PnorIpmiDD;
+#elif (defined(CONFIG_PNORDD_IS_BMCMBOX) || defined(CONFIG_PNORDD_IS_IPMI))
+#include "pnor_hiomapdd.H"
+using PnorDD = PnorHiomapDD;
 #else
-#error "No PNOR DD implementation configured"
+#error "No PNOR DD configured"
 #endif
 
 // Used for creating an Invalid TOC ("PNOR")
diff --git a/src/usr/pnor/test/pnorddtest.H b/src/usr/pnor/test/pnorddtest.H
index 44491d973..fa38413ff 100644
--- a/src/usr/pnor/test/pnorddtest.H
+++ b/src/usr/pnor/test/pnorddtest.H
@@ -40,19 +40,16 @@
 #include <devicefw/userif.H>
 #include <kernel/console.H>
 #include <sys/time.h>
-#ifdef CONFIG_PNORDD_IS_SFC
+#if defined(CONFIG_PNORDD_IS_SFC)
 #include "pnor_sfcdd.H"
 using PnorDD = PnorSfcDD;
-#elif CONFIG_PNORDD_IS_BMCMBOX
-#include "pnor_mboxdd.H"
-using PnorDD = PnorMboxDD;
-#elif CONFIG_PNORDD_IS_IPMI
-#include "pnor_ipmidd.H"
-using PnorDD = PnorIpmiDD;
+#elif (defined(CONFIG_PNORDD_IS_BMCMBOX) || defined(CONFIG_PNORDD_IS_IPMI))
+#include "pnor_hiomapdd.H"
+using PnorDD = PnorHiomapDD;
 #else
-#error "No PNOR DD implementation configured"
+#error "No PNOR DD configured"
 #endif
-#include "../pnorrp.H"
+#include "pnorrp.H"
 #include <list>
 #include <targeting/common/attributes.H>