1/* $NetBSD: pnpbioscall.S,v 1.1 2002/11/22 15:02:12 fvdl Exp $ */ 2/* 3 * Copyright (c) 1999 4 * Matthias Drochner. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions, and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28#include "assym.h" 29#include <machine/asm.h> 30#include <machine/segments.h> 31 32 .data 33saveesp: 34 .space 4 35 36NENTRY(pnpbioscall) 37 pushl %ebp 38 movl %esp, %ebp 39 /* 40 * disable interrupts - our handlers can't deal with frames of the 41 * segment we are calling, and the BIOS can't use our IDT anyway 42 */ 43 pushfl 44 cli 45 46 /* call pnpbiostramp() */ 47 lcall $GSEL(GPNPBIOSTRAMP_SEL, SEL_KPL), $0 48 49 popfl 50 popl %ebp 51 ret 52 53NENTRY(pnpbiostramp) 54 pushl %ebx 55 56 /* save current stack pointer */ 57 movl %esp, %eax 58 movl %eax, saveesp 59 60 /* switch to new stack */ 61 movl 8(%ebp), %esp /* call argument */ 62 movl $GSEL(GPNPBIOSSCRATCH_SEL, SEL_KPL), %eax 63 mov %ax, %ss 64 65 /* fake the call return address (16-bit frame) */ 66 mov %cs, %ax 67 push %ax 68 movl $(1f - _C_LABEL(pnpbiostramp)), %eax 69 push %ax 70 71 /* do a long jump */ 72 pushl $GSEL(GPNPBIOSCODE_SEL, SEL_KPL) 73 pushl (_C_LABEL(pnpbios_entry)) 74#if 1 75 /* paranoia: don't pass our ds */ 76 movl $GSEL(GPNPBIOSSCRATCH_SEL, SEL_KPL), %eax 77 mov %ax, %ds 78#endif 79 lret 80 811: /* returned from BIOS call */ 82 movl $GSEL(GDATA_SEL, SEL_KPL), %ebx 83#if 1 84 mov %bx, %ds 85#endif 86 /* back to old stack */ 87 mov %bx, %ss 88 movl saveesp, %ebx 89 movl %ebx, %esp 90 91 popl %ebx 92 lret 93 .globl _C_LABEL(epnpbiostramp) 94_C_LABEL(epnpbiostramp): 95