Annotation of sys/arch/i386/stand/boot/srt0.S, Revision 1.1.1.1
1.1 nbrk 1: /* $OpenBSD: srt0.S,v 1.14 2003/11/22 09:18:25 grange Exp $ */
2:
3: /*
4: * Copyright (c) 1997 Michael Shalayeff
5: * All rights reserved.
6: *
7: * Redistribution and use in source and binary forms, with or without
8: * modification, are permitted provided that the following conditions
9: * are met:
10: * 1. Redistributions of source code must retain the above copyright
11: * notice, this list of conditions and the following disclaimer.
12: * 2. Redistributions in binary form must reproduce the above copyright
13: * notice, this list of conditions and the following disclaimer in the
14: * documentation and/or other materials provided with the distribution.
15: *
16: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18: * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
20: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26: * SUCH DAMAGE.
27: *
28: */
29: #include <machine/asm.h>
30: #include <assym.h>
31:
32: #define BOOTSTACK 0xfffc
33:
34: .globl _C_LABEL(end)
35: .globl _C_LABEL(edata)
36: .globl _C_LABEL(boot)
37: .globl _C_LABEL(_rtt)
38: .globl _C_LABEL(bios_bootdev)
39: .globl _ASM_LABEL(pmm_init)
40: .globl Gdtr
41:
42: .text
43: .code16
44: .globl _start
45: _start:
46: popl %eax
47: cmpl $BOOTMAGIC, %eax
48: je 1f
49: #ifdef DEBUG
50: movl $0xb80a0, %ebx
51: addr32 movl $0x07420742, (%ebx)
52: #endif
53: 1:
54: popl %edx
55: cli
56: pushl %cs
57: popl %ds
58: addr32 data32 lgdt (Gdtr - LINKADDR)
59: movl %cr0, %eax
60: orl $CR0_PE, %eax
61: data32 movl %eax, %cr0
62: data32 ljmp $8, $1f
63: 1:
64: .code32
65: movl $0x10,%eax
66: mov %ax,%ds
67: mov %ax,%ss
68: mov %ax,%es
69: mov %ax,%fs
70: mov %ax,%gs
71: movl $BOOTSTACK,%esp
72: pushl %edx
73: movl %edx, _C_LABEL(bios_bootdev)
74:
75: /* Now do it all */
76: call _ASM_LABEL(pmm_init)
77: #ifdef DEBUG
78: movl $0xb80a4, %ebx
79: movl $0x07520752, (%ebx)
80: #endif
81: /* zero .bss */
82: xorl %eax, %eax
83: movl $_C_LABEL(end), %ecx
84: subl $_C_LABEL(edata),%ecx
85: movl $_C_LABEL(edata), %edi
86: cld
87: rep; stosb
88:
89: call _C_LABEL(boot)
90:
91: jmp _C_LABEL(_rtt)
92:
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