1 /*-
2 * Copyright (c) 2001 Takanori Watanabe <takawata@jp.freebsd.org>
3 * Copyright (c) 2001-2012 Mitsuru IWASAKI <iwasaki@jp.freebsd.org>
4 * Copyright (c) 2003 Peter Wemm
5 * Copyright (c) 2008-2012 Jung-uk Kim <jkim@FreeBSD.org>
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $FreeBSD: releng/12.0/sys/i386/acpica/acpi_wakecode.S 331254 2018-03-20 17:58:51Z emaste $
30 */
31
32 #include <machine/asmacros.h>
33 #include <machine/ppireg.h>
34 #include <machine/specialreg.h>
35 #include <machine/timerreg.h>
36
37 #include "assym.inc"
38
39 /*
40 * Resume entry point. The BIOS enters here in real mode after POST with
41 * CS set to the page where we stored this code. It should configure the
42 * segment registers with a flat 4 GB address space and EFLAGS.IF = 0.
43 * Depending on the previous sleep state, we may need to initialize more
44 * of the system (i.e., S3 suspend-to-RAM vs. S4 suspend-to-disk).
45 */
46
47 .data /* So we can modify it */
48
49 ALIGN_TEXT
50 .code16
51 wakeup_start:
52 /*
53 * Set up segment registers for real mode and a small stack for
54 * any calls we make. Set up full 32-bit bootstrap kernel flags
55 * since resumectx() doesn't restore flags. PSL_KERNEL gives
56 * bootstrap kernel flags (with interrupts disabled), not normal
57 * kernel flags.
58 */
59 cli /* make sure no interrupts */
60 mov %cs, %ax /* copy %cs to %ds. Remember these */
61 mov %ax, %ds /* are offsets rather than selectors */
62 mov %ax, %ss
63 movw $PAGE_SIZE, %sp
64 pushl $PSL_KERNEL
65 popfl
66
67 /* To debug resume hangs, beep the speaker if the user requested. */
68 testb $~0, resume_beep - wakeup_start
69 jz 1f
70 movb $0, resume_beep - wakeup_start
71
72 /* Set PIC timer2 to beep. */
73 movb $(TIMER_SEL2 | TIMER_SQWAVE | TIMER_16BIT), %al
74 outb %al, $TIMER_MODE
75
76 /* Turn on speaker. */
77 inb $IO_PPI, %al
78 orb $PIT_SPKR, %al
79 outb %al, $IO_PPI
80
81 /* Set frequency. */
82 movw $0x4c0, %ax
83 outb %al, $TIMER_CNTR2
84 shrw $8, %ax
85 outb %al, $TIMER_CNTR2
86 1:
87
88 /* Re-initialize video BIOS if the reset_video tunable is set. */
89 testb $~0, reset_video - wakeup_start
90 jz 1f
91 movb $0, reset_video - wakeup_start
92 lcall $0xc000, $3
93
94 /* When we reach here, int 0x10 should be ready. Hide cursor. */
95 movb $0x01, %ah
96 movb $0x20, %ch
97 int $0x10
98
99 /* Re-start in case the previous BIOS call clobbers them. */
100 jmp wakeup_start
101 1:
102
103 /*
104 * Find relocation base and patch the gdt descript and ljmp targets
105 */
106 xorl %ebx, %ebx
107 mov %cs, %bx
108 sall $4, %ebx /* %ebx is now our relocation base */
109
110 /*
111 * Load the descriptor table pointer. We'll need it when running
112 * in 16-bit protected mode.
113 */
114 lgdtl bootgdtdesc - wakeup_start
115
116 /* Enable protected mode */
117 movl $CR0_PE, %eax
118 mov %eax, %cr0
119
120 /*
121 * Now execute a far jump to turn on protected mode. This
122 * causes the segment registers to turn into selectors and causes
123 * %cs to be loaded from the gdt.
124 *
125 * The following instruction is:
126 * ljmpl $bootcode32 - bootgdt, $wakeup_32 - wakeup_start
127 * but gas cannot assemble that. And besides, we patch the targets
128 * in early startup and its a little clearer what we are patching.
129 */
130 wakeup_sw32:
131 .byte 0x66 /* size override to 32 bits */
132 .byte 0xea /* opcode for far jump */
133 .long wakeup_32 - wakeup_start /* offset in segment */
134 .word bootcode32 - bootgdt /* index in gdt for 32 bit code */
135
136 /*
137 * At this point, we are running in 32 bit legacy protected mode.
138 */
139 ALIGN_TEXT
140 .code32
141 wakeup_32:
142
143 mov $bootdata32 - bootgdt, %eax
144 mov %ax, %ds
145
146 /* Get PCB and return address. */
147 movl wakeup_pcb - wakeup_start(%ebx), %ecx
148 movl wakeup_ret - wakeup_start(%ebx), %edx
149
150 /* Restore CR4 and CR3. */
151 movl wakeup_cr4 - wakeup_start(%ebx), %eax
152 mov %eax, %cr4
153 movl wakeup_cr3 - wakeup_start(%ebx), %eax
154 mov %eax, %cr3
155
156 /* Enable paging. */
157 mov %cr0, %eax
158 orl $CR0_PG, %eax
159 mov %eax, %cr0
160
161 /* Jump to return address. */
162 jmp *%edx
163
164 .data
165
166 resume_beep:
167 .byte 0
168 reset_video:
169 .byte 0
170
171 ALIGN_DATA
172 bootgdt:
173 .long 0x00000000
174 .long 0x00000000
175
176 bootcode32:
177 .long 0x0000ffff
178 .long 0x00cf9b00
179
180 bootdata32:
181 .long 0x0000ffff
182 .long 0x00cf9300
183 bootgdtend:
184
185 bootgdtdesc:
186 .word bootgdtend - bootgdt /* Length */
187 .long bootgdt - wakeup_start /* Offset plus %ds << 4 */
188
189 ALIGN_DATA
190 wakeup_cr4:
191 .long 0
192 wakeup_cr3:
193 .long 0
194 wakeup_pcb:
195 .long 0
196 wakeup_ret:
197 .long 0
198 wakeup_gdt: /* not used */
199 .word 0
200 .long 0
201 dummy:
Cache object: b635c4bdf58f5657bd4ba61b9f70de2d
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