Delphi/ASM code incompatible with 64bit?

Question

I have some sample source code for OpenGL, I wanted to compile a 64bit version (using Delphi XE2) but there's some ASM code which fails to compile, and I know nothing about ASM. Here's the code below, and I put the two error messages on the lines which fail...

// Copy a pixel from source to dest and Swap the RGB color values
procedure CopySwapPixel(const Source, Destination: Pointer);
asm
  push ebx //[DCC Error]: E2116 Invalid combination of opcode and operands
  mov bl,[eax+0]
  mov bh,[eax+1]
  mov [edx+2],bl
  mov [edx+1],bh
  mov bl,[eax+2]
  mov bh,[eax+3]
  mov [edx+0],bl
  mov [edx+3],bh
  pop ebx //[DCC Error]: E2116 Invalid combination of opcode and operands
end;

Answer 1

This procedure swaps ABGR byte order to ARGB and vice versa.
In 32bit this code should do all the job:

mov ecx, [eax]  //ABGR from src
bswap ecx       //RGBA  
ror ecx, 8      //ARGB 
mov [edx], ecx  //to dest

The correct code for X64 is

mov ecx, [rcx]  //ABGR from src
bswap ecx       //RGBA  
ror ecx, 8      //ARGB 
mov [rdx], ecx  //to dest

Yet another option - make pure Pascal version, which changes order of bytes in array representation: 0123 to 2103 (swap 0th and 2th bytes).

procedure Swp(const Source, Destination: Pointer);
var
  s, d: PByteArray;
begin
  s := PByteArray(Source);
  d := PByteArray(Destination);
  d[0] := s[2];
  d[1] := s[1];
  d[2] := s[0];
  d[3] := s[3];
end;

Answer 2

64 bit has different names for pointer registers and it is passed difference. The first four parameters to inline assembler functions are passed via RCX, RDX, R8, and R9 respectively

EBX -> RBX
EAX -> RAX
EDX -> RDX

try this

procedure CopySwapPixel(const Source, Destination: Pointer);
{$IFDEF CPUX64}
asm
  mov al,[rcx+0]
  mov ah,[rcx+1]
  mov [rdx+2],al
  mov [rdx+1],ah
  mov al,[rcx+2]
  mov ah,[rcx+3]
  mov [rdx+0],al
  mov [rdx+3],ah
end;
{$ELSE}
asm
  push ebx //[DCC Error]: E2116 Invalid combination of opcode and operands
  mov bl,[eax+0]
  mov bh,[eax+1]
  mov [edx+2],bl
  mov [edx+1],bh
  mov bl,[eax+2]
  mov bh,[eax+3]
  mov [edx+0],bl
  mov [edx+3],bh
  pop ebx //[DCC Error]: E2116 Invalid combination of opcode and operands
end;
{$ENDIF}