segment .text
  global _asm_main

_asm_main:
  ;entry code
  push ebp
  mov ebp, esp

  mov esp, [ebp+8]
  add esp, 40
  pusha

  mov eax, [ebp+4]  ;   -> push dword[ebp+4]
  push eax    
  
  pushf
  ;exit code
  mov esp, ebp
  pop ebp
  ret

<main.c>

extern int asm_main(struct Context*);

struct Context

{

                  int efl;

                  int eip;

                  int edi;

                  int esi;

                  int ebp;

                  int esp;

                  int ebx;

                  int edx;

                  int ecx;

                  int eax;

};

int main()

{

                  struct Context status;

                  memset(&status, 0, sizeof(struct Context));

                  asm_main(&status);

                  printf("eax=%x\n", status.eax);

                  printf("ecx=%x\n", status.ecx);

                  printf("edx=%x\n", status.edx);

                  printf("ebx=%x\n", status.ebx);

                  printf("esp=%x\n", status.esp);

                  printf("ebp=%x\n", status.ebp);

                  printf("esi=%x\n", status.esi);

                  printf("edi=%x\n", status.edi);

                  printf("eip=%x\n", status.eip);

                  printf("efl=%x\n", status.efl);

                  //printf("%esp=%x\n", &iesp);

                  return 0;