Running DS-5 armcc compiled code (PIC) under Windows EC 2013

Question

Hi All,
i just wanted to know if it is generally (officially) supported to run code that is compiled via the armcc (5.03) from DS-5 under Windows Embedded Compact 2013. Or if this is discouraged (reasons?).
The problem i have:
The bootloader contains some code that must be run during Windows EC Startup. So this code is loaded from the Flash, copied to RAM (reserved and commited via VirtualAlloc and marked as executable) and then the functions are called via FunctionPointers.
The code is compiled and linked as position independent and the stack base register is set accordingly before any function is called via pointer and reset when it returns.
This works in about 9 out of 10 tests without problems. But sometimes i get all sort of exceptions (Data Abort, Prefetch Abort, Unknown Instruction, ...). Most (if not all) of the time they occur when the position independent code runs on one of the two
cores.
The code runs on an i.MX6DQ (dual).
If i only enable one core, i can't reproduce the problem (i assume that multicore-handling and multithreading in WinEC 2013 Update 10 is really well tested and works without problems, so this can't be the real reason).
I've thoroughly checked and debugged the code, i'm really sure there is no illegal access or other problem with the code itself.
Could it be a problem to call code compiled via DS-5 armcc? I've compared assembler code that Visual Studio/Platform Builder generates with code that DS-5 generates (but i'm no assembler expert). I can't see any obvious special code that is added by Visual
Studio/Platform Builder (i.e. that functions need) that is not there in the DS-5 code.
Best Regards
Sebastian

Answer 1

So I think you could be able to image some code for ROM from another compiler and without knowledge of Windows CE. However, if the code will be called from Windows CE, this becomes more difficult requiring very careful isolation from the
MMU state, processor state, kernel/user mode, etc. Code that works great when called from the bootloader might not work at all from Windows CE itself. The main problem with mixing code from different compilers is the object file format and conventions for
entry and public names. Very unlikely that you'd be able to "link" code from any other compiler with PB-compiled code.
You might think about the x86 image which can easily call BIOS from the bootloader but which can't even begin to call BIOS from CE itself. The problem isn't the compiler (which is different), but the operating environment differences and assumptions.
Paul T.