acpi_wakecode.S revision 215200
1/*- 2 * Copyright (c) 2001 Takanori Watanabe <takawata@jp.freebsd.org> 3 * Copyright (c) 2001 Mitsuru IWASAKI <iwasaki@jp.freebsd.org> 4 * 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 * $FreeBSD: head/sys/i386/acpica/acpi_wakecode.S 215200 2010-11-12 20:55:14Z jkim $ 28 */ 29 30#include <machine/asmacros.h> 31#include <machine/specialreg.h> 32 33#include "assym.s" 34 35/* 36 * Resume entry point. The BIOS enters here in real mode after POST with 37 * CS set to the page where we stored this code. It should configure the 38 * segment registers with a flat 4 GB address space and EFLAGS.IF = 0. 39 * Depending on the previous sleep state, we may need to initialize more 40 * of the system (i.e., S3 suspend-to-RAM vs. S4 suspend-to-disk). 41 */ 42 .align 4 43 .code16 44wakeup_16: 45 nop 46 cli 47 cld 48 49 /* 50 * Set up segment registers for real mode, a small stack for 51 * any calls we make, and clear any flags. 52 */ 53 movw %cs,%ax 54 movw %ax,%ds 55 movw %ax,%ss 56 movw $PAGE_SIZE,%sp 57 pushl $0 58 popfl 59 60 /* To debug resume hangs, beep the speaker if the user requested. */ 61 cmpl $1,resume_beep 62 jne nobeep 63 movb $0xc0,%al 64 outb %al,$0x42 65 movb $0x04,%al 66 outb %al,$0x42 67 inb $0x61,%al 68 orb $0x3,%al 69 outb %al,$0x61 70nobeep: 71 72 /* Re-initialize video BIOS if the reset_video tunable is set. */ 73 cmpl $1,reset_video 74 jne nobiosreset 75 lcall $0xc000,$3 76 77 /* 78 * Set up segment registers for real mode again in case the 79 * previous BIOS call clobbers them. 80 */ 81 movw %cs,%ax 82 movw %ax,%ds 83 movw %ax,%ss 84nobiosreset: 85 86 /* Load GDT for real mode. Use 32 bit prefix for addresses >16 MB. */ 87 lgdtl physical_gdt 88 89 /* Restore CR2, CR3 and CR4 */ 90 movl previous_cr2,%eax 91 movl %eax,%cr2 92 movl previous_cr3,%eax 93 movl %eax,%cr3 94 movl previous_cr4,%eax 95 movl %eax,%cr4 96 97 /* Transfer some values to protected mode with an inline stack */ 98#define NVALUES 9 99#define TRANSFER_STACK32(val, idx) \ 100 movl val,%eax; \ 101 movl %eax,wakeup_32stack+(idx+1)+(idx*4) 102 103 TRANSFER_STACK32(previous_ss, (NVALUES - 9)) 104 TRANSFER_STACK32(previous_fs, (NVALUES - 8)) 105 TRANSFER_STACK32(previous_ds, (NVALUES - 7)) 106 TRANSFER_STACK32(physical_gdt+2, (NVALUES - 6)) 107 TRANSFER_STACK32(where_to_recover, (NVALUES - 5)) 108 TRANSFER_STACK32(previous_idt+2, (NVALUES - 4)) 109 TRANSFER_STACK32(previous_ldt, (NVALUES - 3)) 110 TRANSFER_STACK32(previous_gdt+2, (NVALUES - 2)) 111 TRANSFER_STACK32(previous_tr, (NVALUES - 1)) 112 TRANSFER_STACK32(previous_cr0, (NVALUES - 0)) 113 114 mov physical_esp,%esi /* to be used in 32bit code */ 115 116 /* Enable protected mode */ 117 movl %cr0,%eax 118 orl $(CR0_PE),%eax 119 movl %eax,%cr0 120 121wakeup_sw32: 122 /* Switch to protected mode by intersegmental jump */ 123 ljmpl $KCSEL,$0x12345678 /* Code location, to be replaced */ 124 125 /* 126 * Now switched to protected mode without paging enabled. 127 * %esi: KERNEL stack pointer (physical address) 128 */ 129 .code32 130wakeup_32: 131 nop 132 133 /* Set up segment registers for protected mode */ 134 movw $KDSEL,%ax /* KDSEL to segment registers */ 135 movw %ax,%ds 136 movw %ax,%es 137 movw %ax,%gs 138 movw %ax,%ss 139 movw $KPSEL,%ax /* KPSEL to %fs */ 140 movw %ax,%fs 141 movl %esi,%esp /* physical address stack pointer */ 142 143wakeup_32stack: 144 /* Operands are overwritten in 16 bit code by TRANSFER_STACK32 macro */ 145 pushl $0xabcdef09 /* ss + dummy */ 146 pushl $0xabcdef08 /* fs + gs */ 147 pushl $0xabcdef07 /* ds + es */ 148 pushl $0xabcdef06 /* gdt:base (physical address) */ 149 pushl $0xabcdef05 /* recover address */ 150 pushl $0xabcdef04 /* idt:base */ 151 pushl $0xabcdef03 /* ldt + idt:limit */ 152 pushl $0xabcdef02 /* gdt:base */ 153 pushl $0xabcdef01 /* TR + gdt:limit */ 154 pushl $0xabcdef00 /* CR0 */ 155 156 movl %esp,%ebp 157#define CR0_REGISTER 0(%ebp) 158#define TASK_REGISTER 4(%ebp) 159#define PREVIOUS_GDT 6(%ebp) 160#define PREVIOUS_LDT 12(%ebp) 161#define PREVIOUS_IDT 14(%ebp) 162#define RECOVER_ADDR 20(%ebp) 163#define PHYSICAL_GDT_BASE 24(%ebp) 164#define PREVIOUS_DS 28(%ebp) 165#define PREVIOUS_ES 30(%ebp) 166#define PREVIOUS_FS 32(%ebp) 167#define PREVIOUS_GS 34(%ebp) 168#define PREVIOUS_SS 36(%ebp) 169 170 /* Fixup TSS type field */ 171#define TSS_TYPEFIX_MASK 0xf9 172 xorl %esi,%esi 173 movl PHYSICAL_GDT_BASE,%ebx 174 movw TASK_REGISTER,%si 175 leal (%ebx,%esi),%eax /* get TSS segment descriptor */ 176 andb $TSS_TYPEFIX_MASK,5(%eax) 177 178 /* Prepare to return to sleep/wakeup code point */ 179 lgdtl PREVIOUS_GDT 180 lidtl PREVIOUS_IDT 181 182 /* Pack values from the GDT to be loaded into segment registers. */ 183 movl PREVIOUS_DS,%ebx 184 movl PREVIOUS_FS,%ecx 185 movl PREVIOUS_SS,%edx 186 movw TASK_REGISTER,%si 187 shll $16,%esi 188 movw PREVIOUS_LDT,%si 189 movl RECOVER_ADDR,%edi 190 191 /* Enable paging and etc. */ 192 movl CR0_REGISTER,%eax 193 movl %eax,%cr0 194 195 /* Flush the prefetch queue */ 196 jmp 1f 1971: jmp 1f 1981: 199 200 /* 201 * Now we are in kernel virtual memory addressing with the following 202 * original register values: 203 * %ebx: ds + es 204 * %ecx: fs + gs 205 * %edx: ss + dummy 206 * %esi: LDTR + TR 207 * %edi: recover address 208 * We'll load these back into the segment registers now. 209 */ 210 nop 211 212 movl %esi,%eax /* LDTR + TR */ 213 lldt %ax /* load LDT register */ 214 shrl $16,%eax 215 ltr %ax /* load task register */ 216 217 /* Restore segment registers */ 218 movl %ebx,%eax /* ds + es */ 219 movw %ax,%ds 220 shrl $16,%eax 221 movw %ax,%es 222 movl %ecx,%eax /* fs + gs */ 223 movw %ax,%fs 224 shrl $16,%eax 225 movw %ax,%gs 226 movl %edx,%eax /* ss */ 227 movw %ax,%ss 228 229 /* Jump to acpi_restorecpu() */ 230 jmp *%edi 231 232/* used in real mode */ 233physical_gdt: .word 0 234 .long 0 235physical_esp: .long 0 236previous_cr2: .long 0 237previous_cr3: .long 0 238previous_cr4: .long 0 239resume_beep: .long 0 240reset_video: .long 0 241 242/* 243 * Transfer from real mode to protected mode. The order of these variables 244 * is very important, DO NOT INSERT OR CHANGE unless you know why. 245 */ 246previous_cr0: .long 0 247previous_tr: .word 0 248previous_gdt: .word 0 249 .long 0 250previous_ldt: .word 0 251previous_idt: .word 0 252 .long 0 253where_to_recover: .long 0 254previous_ds: .word 0 255previous_es: .word 0 256previous_fs: .word 0 257previous_gs: .word 0 258previous_ss: .word 0 259dummy: .word 0 260