Syslinux - Sep 2003 - Can not use read file SYSLINUX API call

Hi Peter Anvin
I tried to use open file and read file SYSLINUX API. But it always make my
PC104 freeze. My snip code :


===============================================int __start(void)
{
int ax,cx,dx,es,si,di,t;
com32sys_t  inreg,outreg;

memset(&inreg, 0, sizeof inreg);
memset(&outreg, 0, sizeof outreg);
strcopy(__com32.cs_bounce, "test.txt");
inreg.eax.w[0] = 0x0006;  // Open file
inreg.esi.w[0] = OFFS(__com32.cs_bounce);
inreg.es = SEG(__com32.cs_bounce);
__com32.cs_intcall(0x22, &inreg, &outreg);

si = outreg.esi.w[0];
cx = outreg.ecx.w[0];
ax = outreg.eax.w[0];
if ((ax % cx) == 0)
t = ax / cx;
else
t = (ax / cx) + 1;

memset(&inreg, 0, sizeof inreg);
inreg.esi.w[0] = si;
inreg.ecx.w[0] = t;
inreg.eax.w[0] = 0x0007;  // Read file
inreg.ebx.w[0] = OFFS(__com32.cs_bounce);
inreg.es = SEG(__com32.cs_bounce);
__com32.cs_intcall(0x22, &inreg, NULL);

memset(&inreg, 0, sizeof inreg);
inreg.eax.w[0] = 0x0002;  //  Write content of file to console
inreg.ebx.w[0] = OFFS(__com32.cs_bounce);
inreg.es = SEG(__com32.cs_bounce);
__com32.cs_intcall(0x22, &inreg, NULL);

memset(&inreg, 0, sizeof inreg);
inreg.eax.w[0] = 0x000C;  //  Clean up
inreg.edx.w[0] = 0x0000;
__com32.cs_intcall(0x22, &inreg, NULL);

..........................

========================================Please tell me where is the error in my
codes.
Thanks very much

Phung Chi Kien
Automation Institute
Hanoi
Vietnam

Phung Chi Kien wrote:
> Hi Peter Anvin
> I tried to use open file and read file SYSLINUX API. But it always make my
> PC104 freeze. My snip code :
> 
Can you please include the whole file, so that it can be compiled?

	-hpa

Phung Chi Kien wrote:
> 
> memset(&inreg, 0, sizeof inreg);
> inreg.eax.w[0] = 0x000C;  //  Clean up
> inreg.edx.w[0] = 0x0000;
> __com32.cs_intcall(0x22, &inreg, NULL);
> 
Your invoking CLEAN UP here seems rather suspicious.  CLEAN UP means 
that you're taking over full control of the boot process from this point 
on.  Have you tried simply returning?

	-hpa