The easiest way to do this is to compile up your C function
without the #asm and look at the assembly code that is generated. The
-S option is used for this.
Keep in mind that variables fall into two classes: function local
and global. In the code you submitted, the variables are all local.
Bcc uses negative offsets from ebp to access them. The first one
is accessed at -10h[ebp]. Thus, instead of
mov v,eax
you would use
mov -10h[ebp],eax
The next local variable is a longword further off the stack, that is
-14h. Again, write a simple program and look at the BCC output to
know for sure.
The global variables are accessed using their name with an underscore prepended.
Thus, to access global int a:
mov eax,[_a]
Look at generated BCC output. That's how I came up with this!
Greg
On Tuesday, March 23, 1999 1:08 PM, Stacy D. Coil [SMTP:[EMAIL PROTECTED]] wrote:
> Please excuse the slight off topic question. I am trying to use bcc for a
> couple of small routines. There needs to be some assembly in it, and I
> need to pass arguments back and forth. I tried the following:
>
> #define BDOOR_MAGIC 0x564D5868
> #define BDOOR_CMD_GETVERSION 10
> #define BDOOR_PORT 0x5658
>
> typedef unsigned short uint16;
> typedef unsigned uint32;
>
>
>
>
> void
> getVersion(version, magic)
> uint32 *version; uint32 *magic;
> {
> uint32 v;
> uint32 m;
>
>
> #asm
> push eax
> push ebx
> push ecx
> push edx
>
> mov eax, BDOOR_MAGIC
> mov ecx, BDOOR_CMD_GETVERSION
> mov dx, BDOOR_PORT
> in eax, dx
> mov v, eax
> mov m, ebx
>
> pop edx
> pop ecx
> pop ebx
> pop eax
> #endasm
>
> *version = v;
> *magic = m;
>
> }
>
> But this returns and no symbol for v and m. Could someone be kind enough
> to show me how to pass varibles from c to assembly and back?
>
> TIA,
>
> --Stacy
