Fix data format used in OCC communication

Amester and OCC understand only the sequence that is in bytes.
Current OCC pass-through was sending chunk of 4 bytes and that
was breaking the protocol. Since the REST server only handles 4
bytes, OCC pass-through needs to convert array of 4 bytes into
array of 2 bytes prior to sending to OCC driver.

Similarly, pass-through reader now needs to read one byte at a time
than 4 bytes.

Change-Id: Ifc24636f6b1dfb0cc0052362d2982ecfa652fec5
Signed-off-by: Vishwanatha Subbanna <vishwa@linux.vnet.ibm.com>

1 files changed, 12 insertions, 4 deletions

diff --git a/occ_pass_through.cpp b/occ_pass_through.cpp
index 60dbf6c..7027d65 100644
--- a/occ_pass_through.cpp
+++ b/occ_pass_through.cpp
@@ -77,9 +77,17 @@ std::vector<int32_t> PassThrough::send(std::vector<int32_t> command)
 
     std::vector<int32_t> response {};
 
-    // Amester packs data in 4 bytes
-    ssize_t size = command.size() * sizeof(int32_t);
-    auto rc = write((fd)(), command.data(), size);
+    // OCC only understands [bytes] so need array of bytes. Doing this
+    // because rest-server currently treats all int* as 32 bit integer.
+    std::vector<uint8_t> cmdInBytes;
+    cmdInBytes.resize(command.size());
+
+    // Populate uint8_t version of vector.
+    std::transform(command.begin(), command.end(), cmdInBytes.begin(),
+            [](decltype(cmdInBytes)::value_type x){return x;});
+
+    ssize_t size = cmdInBytes.size() * sizeof(decltype(cmdInBytes)::value_type);
+    auto rc = write((fd)(), cmdInBytes.data(), size);
     if (rc < 0 || (rc != size))
     {
         // This would log and terminate since its not handled.
@@ -93,7 +101,7 @@ std::vector<int32_t> PassThrough::send(std::vector<int32_t> command)
     // Now read the response. This would be the content of occ-sram
     while(1)
     {
-        int32_t data {};
+        uint8_t data {};
         auto len = read((fd)(), &data, sizeof(data));
         if (len > 0)
         {