CODEWITHSUNDEEP
c
Hyz Yuzhou
Hyz Yuzhou

Reputation: 83

Inline assembly gets segmentation fault(core dump)

I'm trying to use "int $0x1a" to have bios call, to search PCI device in Linux. It's implemented in C language with inline assembly. The code shows below:

#include<stdio.h>
int findpci(int device_id, int plx_id){
  int result;
  __asm__(
      "pushl %%eax \n\t"
      "pushl %%ebx \n\t"
      "pushl %%ecx \n\t"
      "pushl %%edx \n\t"
      "pushl %%esi \n\t"
      "movl $0xb102, %%eax \n\t"
      "movl %2, %%ecx \n\t"
      "movl %3, %%edx \n\t"
      "movl $0x0000, %%esi \n\t"
      "int  $0x1a \n\t"
      "movl %%ebx, %0 \n\t" 
      "movb %%ah, %1 \n\t"
      "popl %%esi \n\t"
      "popl %%edx \n\t"
      "popl %%ecx \n\t"
      "popl %%ebx \n\t"
      "popl %%eax \n\t"
      :"=r"(result), "=r"(flag)
      :"r"(device_id), "r"(plx_id)
      );
    return result;
}
int main(){
  int c = findpci(0x9050, 0x10B5);
  printf("%d\n", c);  
  return 0;
}

But I got "segmentation fault(core dump)". What's wrong with my code. Is that it could not call "int $0x1a" in the system?

Upvotes: 1

Views: 199

Answers (1)

Jack Whitham
Jack Whitham

Reputation: 609

Is that it could not call "int $0x1a" in the system?

Yes, it's not possible to do BIOS calls from Linux programs. I suggest you look at the lspci program instead.

Upvotes: 1

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