Question

I have a Visual Studio 2008 C++03 project for a Windows Mobile 6 TI OMAP 3430 platform where I would like to optimize some functions using ARM Cortex A8 NEON instructions.
Visual Studio 2008 includes Microsoft ARM Assembler v15.00.20720 (armasm.exe)

I have declared a function in test.h

extern "C" unsigned __int32 Test();

and implemented it in test.asm as

ALIGN
Test FUNCTION
    EXPORT Test
    ldr r0, [r15]   ; load the PC value in to r0
    mov pc, lr      ; return the value of r0
ENDFUNC

I execute the arm assembler in the pre-link event as:

armasm.exe -32 -CPU ARM8 test.asm test.obj

But, I get these errors back from the tool

test.asm(4) : error A0064: code inside data section
1>    ldr r0, [r14]   ; load the PC value in to r0
test.asm(5) : error A0064: code inside data section
1>    mov pc, lr      ; return the value of r0
test.asm(7) warning : A0063: missing END directive
1>ENDFUNC

What is the correct syntax for using the Visual Studio ARM assembler?

Answer 1

ARMASM is very simple to use because many of the options default to reasonable values. Here’s a version of your code that will work:

  AREA my_test, CODE, READONLY  ; name this block of code
  EXPORT test

test proc      ; start of a procedure
     ldr r0,[r15]
     mov pc,lr
     endp      ; end of a procedure

     end       ; end of the file

Update: forgot to include ‘area’