pxe.c

来自「WinAoE is an open source GPLv3 driver fo」· C语言 代码 · 共 86 行

/*
  Copyright 2006-2008, V.
  For contact information, see http://winaoe.org/

  This file is part of WinAoE.

  WinAoE is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  WinAoE is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with WinAoE.  If not, see <http://www.gnu.org/licenses/>.
*/

asm(".code16gcc\n");
#include "pxe.h"
#include "asm.h"
#include "lib.h"

int apivector = 0;

int pxeinit() {
  int v;
  asm(
    "pushw	%%es\n\t"
    "movw	$0x5650, %%ax\n\t"
    "int	$0x1a\n\t"
    "cmpw	$0x564e, %%ax\n\t"
    "je	0f\n\t"
    "xorl	%%eax, %%eax\n\t"
    "jmp	1f\n"
    "0:	les	%%es:0x28(%%bx), %%bx\n\t"
    "movl	%%es:0x10(%%bx), %%eax\n"
    "1:	popw	%%es"
    :"=a"(v)
    :
    :"ebx", "cc"
  );
  apivector = v;
  return v;
}

unsigned short api(unsigned short command, void* commandstruct) {
  unsigned short r;
  asm volatile (
//    "pushfl\n\t"
//    "pushw	%%ds\n\t"
//    "pushw	%%es\n\t"
//    "pushw	%%fs\n\t"
//    "pushw	%%gs\n\t"
//    "pushal\n\t"
    "xorw	%%ax, %%ax\n\t"
    "pushw	%%cs\n\t"
    "pushw	%%bx\n\t"
    "pushw	%%cx\n"
    ".code16\n\t"
    "lcall	*%%cs:_apivector\n"
    ".code16gcc\n\t"
//    "cli\n\t"
    "addw	$6, %%sp\n\t"
//    "movw	%%ax, %%gs\n\t"
//    "popal\n\t"
//    "movw	%%gs, %%ax\n\t"
//    "popw	%%gs\n\t"
//    "popw	%%fs\n\t"
//    "popw	%%es\n\t"
//    "popw	%%ds\n\t"
//    "popfl"
    :"=a"(r)
    :"b"(commandstruct), "c"(command)
    :"cc", "memory"
  );
  return r;
}

void apierror(char *message, unsigned short status) {
  printf("%s: 0x%04x\n", message, status);
  halt();
}