1/* $NetBSD: pnpbioscall.S,v 1.3 2018/07/14 14:29:40 maxv 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 <machine/asm.h> 29__KERNEL_RCSID(0, "$NetBSD: pnpbioscall.S,v 1.3 2018/07/14 14:29:40 maxv Exp $"); 30 31#include "assym.h" 32#include <machine/segments.h> 33 34 .data 35saveesp: 36 .space 4 37 38ENTRY(pnpbioscall) 39 pushl %ebp 40 movl %esp, %ebp 41 /* 42 * disable interrupts - our handlers can't deal with frames of the 43 * segment we are calling, and the BIOS can't use our IDT anyway 44 */ 45 pushfl 46 cli 47 48 /* call pnpbiostramp() */ 49 lcall $GSEL(GPNPBIOSTRAMP_SEL, SEL_KPL), $0 50 51 popfl 52 popl %ebp 53 ret 54 55ENTRY(pnpbiostramp) 56 pushl %ebx 57 58 /* save current stack pointer */ 59 movl %esp, %eax 60 movl %eax, saveesp 61 62 /* switch to new stack */ 63 movl 8(%ebp), %esp /* call argument */ 64 movl $GSEL(GPNPBIOSSCRATCH_SEL, SEL_KPL), %eax 65 mov %ax, %ss 66 67 /* fake the call return address (16-bit frame) */ 68 mov %cs, %ax 69 push %ax 70 movl $(1f - _C_LABEL(pnpbiostramp)), %eax 71 push %ax 72 73 /* do a long jump */ 74 pushl $GSEL(GPNPBIOSCODE_SEL, SEL_KPL) 75 pushl (_C_LABEL(pnpbios_entry)) 76#if 1 77 /* paranoia: don't pass our ds */ 78 movl $GSEL(GPNPBIOSSCRATCH_SEL, SEL_KPL), %eax 79 mov %ax, %ds 80#endif 81 lret 82 831: /* returned from BIOS call */ 84 movl $GSEL(GDATA_SEL, SEL_KPL), %ebx 85#if 1 86 mov %bx, %ds 87#endif 88 /* back to old stack */ 89 mov %bx, %ss 90 movl saveesp, %ebx 91 movl %ebx, %esp 92 93 popl %ebx 94 lret 95 .globl _C_LABEL(epnpbiostramp) 96_C_LABEL(epnpbiostramp): 97