1/*- 2 * Copyright (c) 2001 Takanori Watanabe <takawata@jp.freebsd.org> 3 * Copyright (c) 2001 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 30#include <machine/asmacros.h> 31#include <machine/specialreg.h> 32#include <x86/ppireg.h> 33#include <x86/timerreg.h> 34 35#include "assym.inc" 36 37/* 38 * Resume entry point for real mode. 39 * 40 * If XFirmwareWakingVector is zero and FirmwareWakingVector is non-zero 41 * in FACS, the BIOS enters here in real mode after POST with CS set to 42 * (FirmwareWakingVector >> 4) and IP set to (FirmwareWakingVector & 0xf). 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 * Note: If XFirmwareWakingVector is non-zero, it should disable address 47 * translation/paging and interrupts, load all segment registers with 48 * a flat 4 GB address space, and set EFLAGS.IF to zero. Currently 49 * this mode is not supported by this code. 50 */ 51 52 .data /* So we can modify it */ 53 54 ALIGN_TEXT 55 .code16 56wakeup_start: 57 /* 58 * Set up segment registers for real mode, a small stack for 59 * any calls we make, and clear any flags. 60 */ 61 cli /* make sure no interrupts */ 62 mov %cs, %ax /* copy %cs to %ds. Remember these */ 63 mov %ax, %ds /* are offsets rather than selectors */ 64 mov %ax, %ss 65 movw $PAGE_SIZE, %sp 66 xorw %ax, %ax 67 pushw %ax 68 popfw 69 70 /* To debug resume hangs, beep the speaker if the user requested. */ 71 testb $~0, resume_beep - wakeup_start 72 jz 1f 73 movb $0, resume_beep - wakeup_start 74 75 /* Set PIC timer2 to beep. */ 76 movb $(TIMER_SEL2 | TIMER_SQWAVE | TIMER_16BIT), %al 77 outb %al, $TIMER_MODE 78 79 /* Turn on speaker. */ 80 inb $IO_PPI, %al 81 orb $PIT_SPKR, %al 82 outb %al, $IO_PPI 83 84 /* Set frequency. */ 85 movw $0x4c0, %ax 86 outb %al, $TIMER_CNTR2 87 shrw $8, %ax 88 outb %al, $TIMER_CNTR2 891: 90 91 /* Re-initialize video BIOS if the reset_video tunable is set. */ 92 testb $~0, reset_video - wakeup_start 93 jz 1f 94 movb $0, reset_video - wakeup_start 95 lcall $0xc000, $3 96 97 /* When we reach here, int 0x10 should be ready. Hide cursor. */ 98 movb $0x01, %ah 99 movb $0x20, %ch 100 int $0x10 101 102 /* Re-start in case the previous BIOS call clobbers them. */ 103 jmp wakeup_start 1041: 105 106 /* 107 * Find relocation base and patch the gdt descript and ljmp targets 108 */ 109 xorl %ebx, %ebx 110 mov %cs, %bx 111 sall $4, %ebx /* %ebx is now our relocation base */ 112 113 /* 114 * Load the descriptor table pointer. We'll need it when running 115 * in 16-bit protected mode. 116 */ 117 lgdtl bootgdtdesc - wakeup_start 118 119 /* Enable protected mode */ 120 movl $CR0_PE, %eax 121 mov %eax, %cr0 122 123 /* 124 * Now execute a far jump to turn on protected mode. This 125 * causes the segment registers to turn into selectors and causes 126 * %cs to be loaded from the gdt. 127 * 128 * The following instruction is: 129 * ljmpl $bootcode32 - bootgdt, $wakeup_32 - wakeup_start 130 * but gas cannot assemble that. And besides, we patch the targets 131 * in early startup and its a little clearer what we are patching. 132 */ 133wakeup_sw32: 134 .byte 0x66 /* size override to 32 bits */ 135 .byte 0xea /* opcode for far jump */ 136 .long wakeup_32 - wakeup_start /* offset in segment */ 137 .word bootcode32 - bootgdt /* index in gdt for 32 bit code */ 138 139 /* 140 * At this point, we are running in 32 bit legacy protected mode. 141 */ 142 ALIGN_TEXT 143 .code32 144wakeup_32: 145 146 mov $bootdata32 - bootgdt, %eax 147 mov %ax, %ds 148 149 /* 150 * Turn on the PAE bit and optionally the LA57 bit for when paging 151 * is later enabled. 152 */ 153 mov %cr4, %eax 154 orl $CR4_PAE, %eax 155 leal wakeup_pagetables - wakeup_start(%ebx), %ecx 156 movl (%ecx), %ecx 157 testl $0x1, %ecx 158 je 1f 159 orl $CR4_LA57, %eax 1601: mov %eax, %cr4 161 162 /* 163 * Enable EFER.LME so that we get long mode when all the prereqs are 164 * in place. In this case, it turns on when CR0_PG is finally enabled. 165 * Also it picks up a few other EFER bits that we'll use need we're 166 * here, like SYSCALL and NX enable. 167 */ 168 movl $MSR_EFER, %ecx 169 movl wakeup_efer - wakeup_start(%ebx), %eax 170 movl wakeup_efer + 4 - wakeup_start(%ebx), %edx 171 wrmsr 172 173 /* 174 * Point to the embedded page tables for startup. Note that this 175 * only gets accessed after we're actually in 64 bit mode, however 176 * we can only set the bottom 32 bits of %cr3 in this state. This 177 * means we are required to use a temporary page table that is below 178 * the 4GB limit. %ebx is still our relocation base. We could just 179 * subtract 3 * PAGE_SIZE, but that would be too easy. 180 */ 181 leal wakeup_pagetables - wakeup_start(%ebx), %eax 182 movl (%eax), %eax 183 andl $~0x1, %eax 184 mov %eax, %cr3 185 186 /* 187 * Finally, switch to long bit mode by enabling paging. We have 188 * to be very careful here because all the segmentation disappears 189 * out from underneath us. The spec says we can depend on the 190 * subsequent pipelined branch to execute, but *only if* everything 191 * is still identity mapped. If any mappings change, the pipeline 192 * will flush. 193 */ 194 mov %cr0, %eax 195 orl $CR0_PG, %eax 196 mov %eax, %cr0 197 198 /* 199 * At this point paging is enabled, and we are in "compatibility" mode. 200 * We do another far jump to reload %cs with the 64 bit selector. 201 * %cr3 points to a 4-level page table page. 202 * We cannot yet jump all the way to the kernel because we can only 203 * specify a 32 bit linear address. So, yet another trampoline. 204 * 205 * The following instruction is: 206 * ljmp $bootcode64 - bootgdt, $wakeup_64 - wakeup_start 207 * but gas cannot assemble that. And besides, we patch the targets 208 * in early startup and its a little clearer what we are patching. 209 */ 210wakeup_sw64: 211 .byte 0xea /* opcode for far jump */ 212 .long wakeup_64 - wakeup_start /* offset in segment */ 213 .word bootcode64 - bootgdt /* index in gdt for 64 bit code */ 214 215 /* 216 * Yeehar! We're running in 64-bit mode! We can mostly ignore our 217 * segment registers, and get on with it. 218 * Note that we are running at the correct virtual address, but with 219 * a 1:1 1GB mirrored mapping over entire address space. We had better 220 * switch to a real %cr3 promptly so that we can get to the direct map 221 * space. Remember that jmp is relative and that we've been relocated, 222 * so use an indirect jump. 223 */ 224 ALIGN_TEXT 225 .code64 226wakeup_64: 227 mov $bootdata64 - bootgdt, %eax 228 mov %ax, %ds 229 230 /* Restore arguments. */ 231 movq wakeup_pcb - wakeup_start(%rbx), %rdi 232 movq wakeup_ret - wakeup_start(%rbx), %rax 233 234 /* Restore GDT. */ 235 lgdt wakeup_gdt - wakeup_start(%rbx) 236 237 /* Jump to return address. */ 238 jmp *%rax 239 240 .data 241 242resume_beep: 243 .byte 0 244reset_video: 245 .byte 0 246 247 ALIGN_DATA 248bootgdt: 249 .long 0x00000000 250 .long 0x00000000 251 .long 0x00000000 252 .long 0x00000000 253 .long 0x00000000 254 .long 0x00000000 255 .long 0x00000000 256 .long 0x00000000 257 258bootcode64: 259 .long 0x0000ffff 260 .long 0x00af9b00 261 262bootdata64: 263 .long 0x0000ffff 264 .long 0x00af9300 265 266bootcode32: 267 .long 0x0000ffff 268 .long 0x00cf9b00 269 270bootdata32: 271 .long 0x0000ffff 272 .long 0x00cf9300 273bootgdtend: 274 275wakeup_pagetables: 276 .long 0 277 278bootgdtdesc: 279 .word bootgdtend - bootgdt /* Length */ 280 .long bootgdt - wakeup_start /* Offset plus %ds << 4 */ 281 282 ALIGN_DATA 283wakeup_pcb: 284 .quad 0 285wakeup_ret: 286 .quad 0 287wakeup_efer: 288 .quad 0 289wakeup_gdt: 290 .word 0 291 .quad 0 292dummy: 293