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) 2008-2009 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 * $FreeBSD$ 30 */ 31 32#define LOCORE 33 34#include <machine/asmacros.h> 35#include <machine/specialreg.h> 36 37#include "assym.s" 38 39/* 40 * Resume entry point for real mode. 41 * 42 * If XFirmwareWakingVector is zero and FirmwareWakingVector is non-zero 43 * in FACS, the BIOS enters here in real mode after POST with CS set to 44 * (FirmwareWakingVector >> 4) and IP set to (FirmwareWakingVector & 0xf). 45 * Depending on the previous sleep state, we may need to initialize more 46 * of the system (i.e., S3 suspend-to-RAM vs. S4 suspend-to-disk). 47 * 48 * Note: If XFirmwareWakingVector is non-zero, it should disable address 49 * translation/paging and interrupts, load all segment registers with 50 * a flat 4 GB address space, and set EFLAGS.IF to zero. Currently 51 * this mode is not supported by this code. 52 */ 53 54 .data /* So we can modify it */ 55 56 ALIGN_TEXT 57wakeup_start: 58 .code16 59 /* 60 * Set up segment registers for real mode, a small stack for 61 * any calls we make, and clear any flags. 62 */ 63 cli /* make sure no interrupts */ 64 cld 65 mov %cs, %ax /* copy %cs to %ds. Remember these */ 66 mov %ax, %ds /* are offsets rather than selectors */ 67 mov %ax, %ss 68 movw $PAGE_SIZE - 8, %sp 69 xorw %ax, %ax 70 pushw %ax 71 popfw 72 73 /* To debug resume hangs, beep the speaker if the user requested. */ 74 testb $~0, resume_beep - wakeup_start 75 jz 1f 76 movb $0, resume_beep - wakeup_start 77 movb $0xc0, %al 78 outb %al, $0x42 79 movb $0x04, %al 80 outb %al, $0x42 81 inb $0x61, %al 82 orb $0x3, %al 83 outb %al, $0x61 841: 85 86 /* Re-initialize video BIOS if the reset_video tunable is set. */ 87 testb $~0, reset_video - wakeup_start 88 jz 1f 89 movb $0, reset_video - wakeup_start 90 lcall $0xc000, $3 91 92 /* Re-start in case the previous BIOS call clobbers them. */ 93 jmp wakeup_start 941: 95 96 /* 97 * Find relocation base and patch the gdt descript and ljmp targets 98 */ 99 xorl %ebx, %ebx 100 mov %cs, %bx 101 sall $4, %ebx /* %ebx is now our relocation base */ 102 103 /* 104 * Load the descriptor table pointer. We'll need it when running 105 * in 16-bit protected mode. 106 */ 107 lgdtl bootgdtdesc - wakeup_start 108 109 /* Enable protected mode */ 110 movl $CR0_PE, %eax 111 mov %eax, %cr0 112 113 /* 114 * Now execute a far jump to turn on protected mode. This 115 * causes the segment registers to turn into selectors and causes 116 * %cs to be loaded from the gdt. 117 * 118 * The following instruction is: 119 * ljmpl $bootcode32 - bootgdt, $wakeup_32 - wakeup_start 120 * but gas cannot assemble that. And besides, we patch the targets 121 * in early startup and its a little clearer what we are patching. 122 */ 123wakeup_sw32: 124 .byte 0x66 /* size override to 32 bits */ 125 .byte 0xea /* opcode for far jump */ 126 .long wakeup_32 - wakeup_start /* offset in segment */ 127 .word bootcode32 - bootgdt /* index in gdt for 32 bit code */ 128 129 /* 130 * At this point, we are running in 32 bit legacy protected mode. 131 */ 132 .code32 133wakeup_32: 134 135 mov $bootdata32 - bootgdt, %eax 136 mov %ax, %ds 137 138 /* Turn on the PAE and PSE bits for when paging is enabled */ 139 mov %cr4, %eax 140 orl $(CR4_PAE | CR4_PSE), %eax 141 mov %eax, %cr4 142 143 /* 144 * Enable EFER.LME so that we get long mode when all the prereqs are 145 * in place. In this case, it turns on when CR0_PG is finally enabled. 146 * Pick up a few other EFER bits that we'll use need we're here. 147 */ 148 movl $MSR_EFER, %ecx 149 rdmsr 150 orl $EFER_LME | EFER_SCE, %eax 151 wrmsr 152 153 /* 154 * Point to the embedded page tables for startup. Note that this 155 * only gets accessed after we're actually in 64 bit mode, however 156 * we can only set the bottom 32 bits of %cr3 in this state. This 157 * means we are required to use a temporary page table that is below 158 * the 4GB limit. %ebx is still our relocation base. We could just 159 * subtract 3 * PAGE_SIZE, but that would be too easy. 160 */ 161 leal wakeup_pagetables - wakeup_start(%ebx), %eax 162 movl (%eax), %eax 163 mov %eax, %cr3 164 165 /* 166 * Finally, switch to long bit mode by enabling paging. We have 167 * to be very careful here because all the segmentation disappears 168 * out from underneath us. The spec says we can depend on the 169 * subsequent pipelined branch to execute, but *only if* everthing 170 * is still identity mapped. If any mappings change, the pipeline 171 * will flush. 172 */ 173 mov %cr0, %eax 174 orl $CR0_PG, %eax 175 mov %eax, %cr0 176 177 /* 178 * At this point paging is enabled, and we are in "compatability" mode. 179 * We do another far jump to reload %cs with the 64 bit selector. 180 * %cr3 points to a 4-level page table page. 181 * We cannot yet jump all the way to the kernel because we can only 182 * specify a 32 bit linear address. So, yet another trampoline. 183 * 184 * The following instruction is: 185 * ljmp $bootcode64 - bootgdt, $wakeup_64 - wakeup_start 186 * but gas cannot assemble that. And besides, we patch the targets 187 * in early startup and its a little clearer what we are patching. 188 */ 189wakeup_sw64: 190 .byte 0xea /* opcode for far jump */ 191 .long wakeup_64 - wakeup_start /* offset in segment */ 192 .word bootcode64 - bootgdt /* index in gdt for 64 bit code */ 193 194 /* 195 * Yeehar! We're running in 64-bit mode! We can mostly ignore our 196 * segment registers, and get on with it. 197 * Note that we are running at the correct virtual address, but with 198 * a 1:1 1GB mirrored mapping over entire address space. We had better 199 * switch to a real %cr3 promptly so that we can get to the direct map 200 * space. Remember that jmp is relative and that we've been relocated, 201 * so use an indirect jump. 202 */ 203 ALIGN_TEXT 204 .code64 205wakeup_64: 206 mov $bootdata64 - bootgdt, %eax 207 mov %ax, %ds 208 209 /* Restore arguments and return. */ 210 movq wakeup_ctx - wakeup_start(%rbx), %rdi 211 movq wakeup_kpml4 - wakeup_start(%rbx), %rsi 212 movq wakeup_retaddr - wakeup_start(%rbx), %rax 213 jmp *%rax 214 215 .data 216 217resume_beep: 218 .byte 0 219reset_video: 220 .byte 0 221 222 ALIGN_DATA 223bootgdt: 224 .long 0x00000000 225 .long 0x00000000 226 .long 0x00000000 227 .long 0x00000000 228 .long 0x00000000 229 .long 0x00000000 230 .long 0x00000000 231 .long 0x00000000 232 233bootcode64: 234 .long 0x0000ffff 235 .long 0x00af9b00 236 237bootdata64: 238 .long 0x0000ffff 239 .long 0x00af9300 240 241bootcode32: 242 .long 0x0000ffff 243 .long 0x00cf9b00 244 245bootdata32: 246 .long 0x0000ffff 247 .long 0x00cf9300 248bootgdtend: 249 250wakeup_pagetables: 251 .long 0 252 253bootgdtdesc: 254 .word bootgdtend - bootgdt /* Length */ 255 .long bootgdt - wakeup_start /* Offset plus %ds << 4 */ 256 257 ALIGN_DATA 258wakeup_retaddr: 259 .quad 0 260wakeup_kpml4: 261 .quad 0 262 263wakeup_ctx: 264 .quad 0 265wakeup_xpcb: 266 .quad 0 267wakeup_gdt: 268 .word 0 269 .quad 0 270 271 ALIGN_DATA 272wakeup_efer: 273 .quad 0 274wakeup_pat: 275 .quad 0 276wakeup_star: 277 .quad 0 278wakeup_lstar: 279 .quad 0 280wakeup_cstar: 281 .quad 0 282wakeup_sfmask: 283 .quad 0 284wakeup_cpu: 285 .long 0 286dummy: 287