Fix #437: Avoid alignment warnings on some CPUs

On CPUs with strict alignment requirements, some CFE code
that uses a char-type pointer (e.g. uint8*) to compute
memory addresses triggers an alignment warning when it gets
cast back to the actual data type.

This code should be alignment-safe already, because the address
computation already takes CPU alignment requirements into account
when calculating the addresses/offsets.

However, the compiler still flags the final conversion from a
pointer with no special alignment to something with alignment
requirements.

- For the CFE_SB pool buffers, using the `cpuaddr` type, which
  is integer in nature, avoids the warning.
- For the CFE_TBL internal table pointer, use a `void*` internally
  to store the buffer pointer, rather than a `uint8_t*`.  This
  changes the casting needs elsewhere.

fsw/cfe-core/src/sb/cfe_sb_api.c

@@ -1802,7 +1802,7 @@ CFE_SB_Msg_t  *CFE_SB_ZeroCopyGetPtr(uint16 MsgSize,
 {
    int32                stat1;
    uint32               AppId = 0xFFFFFFFF;
-   uint8               *address = NULL;
+   cpuaddr              address = 0;
    CFE_SB_ZeroCopyD_t  *zcd = NULL;
    CFE_SB_BufferD_t    *bd = NULL;
 
@@ -1849,7 +1849,7 @@ CFE_SB_Msg_t  *CFE_SB_ZeroCopyGetPtr(uint16 MsgSize,
     }/* end if */
 
     /* first set ptr to actual msg buffer the same as ptr to descriptor */
-    address = (uint8 *)bd;
+    address = (cpuaddr)bd;
 
     /* increment actual msg buffer ptr beyond the descriptor */
     address += sizeof(CFE_SB_BufferD_t);
@@ -1914,6 +1914,7 @@ int32 CFE_SB_ZeroCopyReleasePtr(CFE_SB_Msg_t  *Ptr2Release,
 {
     int32    Status;
     int32    Stat2;
+    cpuaddr  Addr = (cpuaddr)Ptr2Release;
 
     Status = CFE_SB_ZeroCopyReleaseDesc(Ptr2Release, BufferHandle);
 
@@ -1922,7 +1923,7 @@ int32 CFE_SB_ZeroCopyReleasePtr(CFE_SB_Msg_t  *Ptr2Release,
     if(Status == CFE_SUCCESS){
         /* give the buffer back to the buffer pool */
         Stat2 = CFE_ES_PutPoolBuf(CFE_SB.Mem.PoolHdl,
-                                  (uint32 *) (((uint8 *)Ptr2Release) - sizeof(CFE_SB_BufferD_t)));
+                                  (uint32 *) (Addr - sizeof(CFE_SB_BufferD_t)));
         if(Stat2 > 0){
              /* Substract the size of the actual buffer from the Memory in use ctr */
             CFE_SB.StatTlmMsg.Payload.MemInUse-=Stat2;

fsw/cfe-core/src/sb/cfe_sb_buf.c

@@ -116,7 +116,7 @@ CFE_SB_BufferD_t * CFE_SB_GetBufferFromPool(CFE_SB_MsgId_t MsgId, uint16 Size) {
 
 CFE_SB_BufferD_t * CFE_SB_GetBufferFromCaller(CFE_SB_MsgId_t MsgId,
                                               void *Address) {
-   CFE_SB_BufferD_t    *bd = (CFE_SB_BufferD_t *)(((uint8 *)Address) - sizeof(CFE_SB_BufferD_t));
+   CFE_SB_BufferD_t    *bd = (CFE_SB_BufferD_t *)((cpuaddr)Address - sizeof(CFE_SB_BufferD_t));
 
     /* Initialize the MsgId in the buffer descriptor (the rest has already been initialized in this case). */
     bd->MsgId     = MsgId;

fsw/cfe-core/src/tbl/cfe_tbl_internal.c

@@ -486,7 +486,7 @@ int32 CFE_TBL_RemoveAccessLink(CFE_TBL_Handle_t TblHandle)
         if (RegRecPtr->UserDefAddr == false)
         {
             /* Free memory allocated to buffers */
-            Status = CFE_ES_PutPoolBuf(CFE_TBL_TaskData.Buf.PoolHdl, (uint32 *)RegRecPtr->Buffers[0].BufferPtr);
+            Status = CFE_ES_PutPoolBuf(CFE_TBL_TaskData.Buf.PoolHdl, RegRecPtr->Buffers[0].BufferPtr);
             RegRecPtr->Buffers[0].BufferPtr = NULL;
 
             if (Status < 0)
@@ -498,7 +498,7 @@ int32 CFE_TBL_RemoveAccessLink(CFE_TBL_Handle_t TblHandle)
             /* If a double buffered table, then free the second buffer as well */
             if (RegRecPtr->DoubleBuffered)
             {
-                Status = CFE_ES_PutPoolBuf(CFE_TBL_TaskData.Buf.PoolHdl, (uint32 *)RegRecPtr->Buffers[1].BufferPtr);
+                Status = CFE_ES_PutPoolBuf(CFE_TBL_TaskData.Buf.PoolHdl, RegRecPtr->Buffers[1].BufferPtr);
                 RegRecPtr->Buffers[1].BufferPtr = NULL;
 
                 if (Status < 0)
@@ -986,7 +986,7 @@ int32 CFE_TBL_LoadFromFile(CFE_TBL_LoadBuff_t *WorkingBufferPtr,
                         }
 
                         NumBytes = OS_read(FileDescriptor,
-                                           &WorkingBufferPtr->BufferPtr[TblFileHeader.Offset],
+                                           ((uint8*)WorkingBufferPtr->BufferPtr) + TblFileHeader.Offset,
                                            TblFileHeader.NumBytes);
 
                         if (NumBytes != TblFileHeader.NumBytes)

fsw/cfe-core/src/tbl/cfe_tbl_task.h

@@ -145,7 +145,7 @@ typedef struct
 */
 typedef struct 
 {
-    uint8         *BufferPtr;                   /**< \brief Pointer to Load Buffer */
+    void          *BufferPtr;                   /**< \brief Pointer to Load Buffer */
     uint32         FileCreateTimeSecs;          /**< \brief File creation time from last file loaded into table */
     uint32         FileCreateTimeSubSecs;       /**< \brief File creation time from last file loaded into table */
     uint32         Crc;                         /**< \brief Last calculated CRC for this buffer's contents */

fsw/cfe-core/src/tbl/cfe_tbl_task_cmds.c

@@ -441,7 +441,7 @@ int32 CFE_TBL_LoadCmd(const CFE_TBL_Load_t *data)
                         {
                             /* Copy data from file into working buffer */
                             Status = OS_read(FileDescriptor,
-                                             &WorkingBufferPtr->BufferPtr[TblFileHeader.Offset],
+                                             ((uint8*)WorkingBufferPtr->BufferPtr) + TblFileHeader.Offset,
                                              TblFileHeader.NumBytes);
 
                             /* Make sure the appropriate number of bytes were read */

fsw/cfe-core/unit-test/tbl_UT.c

@@ -1688,7 +1688,7 @@ void Test_CFE_TBL_HousekeepingCmd(void)
     CFE_TBL_LoadBuff_t    *DumpBuffPtr = &DumpBuff;
     CFE_TBL_RegistryRec_t RegRecPtr;
     uint8                 Buff;
-    uint8                 *BuffPtr = &Buff;
+    void                  *BuffPtr = &Buff;
     uint32                Secs = 0;
     uint32                SubSecs = 0;
     int32                 LoadInProg = 0;