Remove i386 support.
[dragonfly.git] / sys / platform / pc32 / i386 / bioscall.s
CommitLineData
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1/*-
2 * Copyright (c) 1997 Jonathan Lemon
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: src/sys/i386/i386/bioscall.s,v 1.6.2.1 2000/07/07 00:38:46 obrien Exp $
70c38abb 27 * $DragonFly: src/sys/platform/pc32/i386/bioscall.s,v 1.4 2003/11/07 17:59:23 dillon Exp $
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28 */
29
30/*
31 * Functions for calling x86 BIOS functions from the BSD kernel
32 */
33
34#include <machine/asmacros.h>
35
36#include "assym.s"
37
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38 .data
39 ALIGN_DATA
40bioscall_frame: .long 0
41bioscall_stack: .long 0
42
43 .text
44/*
45 * bios32(regs, offset, segment)
46 * struct bios_regs *regs;
47 * u_int offset;
48 * u_short segment;
49 */
50ENTRY(bios32)
51 pushl %ebp
52 movl 16(%esp),%ebp
2954c92f 53 mov %bp,bioscall_vector+4
984263bc 54 movl 12(%esp),%ebp
2954c92f 55 movl %ebp,bioscall_vector
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56 movl 8(%esp),%ebp
57 pushl %ebx
58 pushl %esi
59 pushl %edi
60 movl 0(%ebp),%eax
61 movl 4(%ebp),%ebx
62 movl 8(%ebp),%ecx
63 movl 12(%ebp),%edx
64 movl 16(%ebp),%esi
65 movl 20(%ebp),%edi
66 pushl %ebp
2954c92f 67 lcall *bioscall_vector
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68 popl %ebp
69 movl %eax,0(%ebp)
70 movl %ebx,4(%ebp)
71 movl %ecx,8(%ebp)
72 movl %edx,12(%ebp)
73 movl %esi,16(%ebp)
74 movl %edi,20(%ebp)
75 movl $0,%eax /* presume success */
76 jnc 1f
77 movl $1,%eax /* nope */
781:
79 popl %edi
80 popl %esi
81 popl %ebx
82 popl %ebp
83 ret
84
85
86/*
87 * bios16_call(regs, stack)
88 * struct bios_regs *regs;
89 * char *stack;
90 */
91ENTRY(bios16_call)
92 pushl %ebp
93 movl %esp,%ebp
94 addl $4,%ebp /* frame pointer */
95 movl %ebp,bioscall_frame /* ... save it */
96 pushl %ebx
97 pushl %esi
98 pushl %edi
99/*
100 * the problem with a full 32-bit stack segment is that 16-bit code
101 * tends to do a pushf, which only pushes %sp, not %esp. This value
102 * is then popped off (into %esp) which causes a page fault because
103 * it is the wrong address.
104 *
105 * the reverse problem happens for 16-bit stack addresses; the kernel
106 * code attempts to get the address of something on the stack, and the
107 * value returned is the address relative to %ss, not %ds.
108 *
109 * we fix this by installing a temporary stack at page 0, so the
110 * addresses are always valid in both 32 bit and 16 bit modes.
111 */
112 movl %esp,bioscall_stack /* save current stack location */
113 movl 8(%ebp),%esp /* switch to page 0 stack */
114
115 movl 4(%ebp),%ebp /* regs */
116
117 movl 0(%ebp),%eax
118 movl 4(%ebp),%ebx
119 movl 8(%ebp),%ecx
120 movl 12(%ebp),%edx
121 movl 16(%ebp),%esi
122 movl 20(%ebp),%edi
123
124 pushl $BC32SEL
125 leal CNAME(bios16_jmp),%ebp
126 andl $PAGE_MASK,%ebp
127 pushl %ebp /* reload %cs and */
128 lret /* ...continue below */
129 .globl CNAME(bios16_jmp)
130CNAME(bios16_jmp):
70c38abb 131 lcallw *bioscall_vector /* 16-bit call */
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132
133 jc 1f
134 pushl $0 /* success */
135 jmp 2f
1361:
137 pushl $1 /* failure */
1382:
139 movl bioscall_frame,%ebp
140
141 movl 4(%ebp),%ebp /* regs */
142
143 movl %eax,0(%ebp)
144 movl %ebx,4(%ebp)
145 movl %ecx,8(%ebp)
146 movl %edx,12(%ebp)
147 movl %esi,16(%ebp)
148 movl %edi,20(%ebp)
149
150 popl %eax /* recover return value */
151 movl bioscall_stack,%esp /* return to normal stack */
152
153 popl %edi
154 popl %esi
155 popl %ebx
156 popl %ebp
157
158 movl (%esp),%ecx
159 pushl %ecx /* return address */
160 movl $KCSEL,4(%esp)
161 lret /* reload %cs on the way out */