x86/test/exit42.c

   1 #include "alchemist/x86.h"
   2
   3 int main(int argc, char **argv) {
   4   char code[0x10000];
   5   int n = 0;
   6
   7   /*** write code ***/
   8
   9   /* xor eax, eax */
  10   n += cg_x86_emit_reg32_reg32_instr(code + n,
  11                                      sizeof(code - n),
  12                                      CG_X86_OP_XOR,
  13                                      CG_X86_REG_EAX,
  14                                      CG_X86_REG_EAX);
  15   /* inc eax */
  16   n += cg_x86_emit_reg32_instr(code + n,
  17                                sizeof(code) - n,
  18                                CG_X86_OP_INC,
  19                                CG_X86_REG_EAX);
  20   /* xor ebx, ebx */
  21   n += cg_x86_emit_reg32_reg32_instr(code + n,
  22                                      sizeof(code) - n,
  23                                      CG_X86_OP_XOR,
  24                                      CG_X86_REG_EBX,
  25                                      CG_X86_REG_EBX);
  26   /* or ebx, 42 */
  27   n += cg_x86_emit_reg32_imm8_instr(code + n,
  28                                     sizeof(code) - n,
  29                                     CG_X86_OP_OR,
  30                                     CG_X86_REG_EBX,
  31                                     42);
  32   /* int 0x80 */
  33   n += cg_x86_emit_imm8_instr(code + n,
  34                               sizeof(code) - n,
  35                               CG_X86_OP_INT,
  36                               0x80);
  37
  38   /*** invoke code ***/
  39   ((void (*) ()) code)();
  40
  41   /*** should not be reached ***/
  42   return 0;
  43 }