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 * $FreeBSD$
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 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
57 .code16
58 wakeup_start:
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 mov %cs, %ax /* copy %cs to %ds. Remember these */
65 mov %ax, %ds /* are offsets rather than selectors */
66 mov %ax, %ss
67 movw $PAGE_SIZE, %sp
68 xorw %ax, %ax
69 pushw %ax
70 popfw
71
72 /* To debug resume hangs, beep the speaker if the user requested. */
73 testb $~0, resume_beep - wakeup_start
74 jz 1f
75 movb $0, resume_beep - wakeup_start
76
77 /* Set PIC timer2 to beep. */
78 movb $(TIMER_SEL2 | TIMER_SQWAVE | TIMER_16BIT), %al
79 outb %al, $TIMER_MODE
80
81 /* Turn on speaker. */
82 inb $IO_PPI, %al
83 orb $PIT_SPKR, %al
84 outb %al, $IO_PPI
85
86 /* Set frequency. */
87 movw $0x4c0, %ax
88 outb %al, $TIMER_CNTR2
89 shrw $8, %ax
90 outb %al, $TIMER_CNTR2
91 1:
92
93 /* Re-initialize video BIOS if the reset_video tunable is set. */
94 testb $~0, reset_video - wakeup_start
95 jz 1f
96 movb $0, reset_video - wakeup_start
97 lcall $0xc000, $3
98
99 /* When we reach here, int 0x10 should be ready. Hide cursor. */
100 movb $0x01, %ah
101 movb $0x20, %ch
102 int $0x10
103
104 /* Re-start in case the previous BIOS call clobbers them. */
105 jmp wakeup_start
106 1:
107
108 /*
109 * Find relocation base and patch the gdt descript and ljmp targets
110 */
111 xorl %ebx, %ebx
112 mov %cs, %bx
113 sall $4, %ebx /* %ebx is now our relocation base */
114
115 /*
116 * Load the descriptor table pointer. We'll need it when running
117 * in 16-bit protected mode.
118 */
119 lgdtl bootgdtdesc - wakeup_start
120
121 /* Enable protected mode */
122 movl $CR0_PE, %eax
123 mov %eax, %cr0
124
125 /*
126 * Now execute a far jump to turn on protected mode. This
127 * causes the segment registers to turn into selectors and causes
128 * %cs to be loaded from the gdt.
129 *
130 * The following instruction is:
131 * ljmpl $bootcode32 - bootgdt, $wakeup_32 - wakeup_start
132 * but gas cannot assemble that. And besides, we patch the targets
133 * in early startup and its a little clearer what we are patching.
134 */
135 wakeup_sw32:
136 .byte 0x66 /* size override to 32 bits */
137 .byte 0xea /* opcode for far jump */
138 .long wakeup_32 - wakeup_start /* offset in segment */
139 .word bootcode32 - bootgdt /* index in gdt for 32 bit code */
140
141 /*
142 * At this point, we are running in 32 bit legacy protected mode.
143 */
144 ALIGN_TEXT
145 .code32
146 wakeup_32:
147
148 mov $bootdata32 - bootgdt, %eax
149 mov %ax, %ds
150
151 /*
152 * Turn on the PAE bit and optionally the LA57 bit for when paging
153 * is later enabled.
154 */
155 mov %cr4, %eax
156 orl $CR4_PAE, %eax
157 leal wakeup_pagetables - wakeup_start(%ebx), %ecx
158 movl (%ecx), %ecx
159 testl $0x1, %ecx
160 je 1f
161 orl $CR4_LA57, %eax
162 1: mov %eax, %cr4
163
164 /*
165 * Enable EFER.LME so that we get long mode when all the prereqs are
166 * in place. In this case, it turns on when CR0_PG is finally enabled.
167 * Also it picks up a few other EFER bits that we'll use need we're
168 * here, like SYSCALL and NX enable.
169 */
170 movl $MSR_EFER, %ecx
171 movl wakeup_efer - wakeup_start(%ebx), %eax
172 movl wakeup_efer + 4 - wakeup_start(%ebx), %edx
173 wrmsr
174
175 /*
176 * Point to the embedded page tables for startup. Note that this
177 * only gets accessed after we're actually in 64 bit mode, however
178 * we can only set the bottom 32 bits of %cr3 in this state. This
179 * means we are required to use a temporary page table that is below
180 * the 4GB limit. %ebx is still our relocation base. We could just
181 * subtract 3 * PAGE_SIZE, but that would be too easy.
182 */
183 leal wakeup_pagetables - wakeup_start(%ebx), %eax
184 movl (%eax), %eax
185 andl $~0x1, %eax
186 mov %eax, %cr3
187
188 /*
189 * Finally, switch to long bit mode by enabling paging. We have
190 * to be very careful here because all the segmentation disappears
191 * out from underneath us. The spec says we can depend on the
192 * subsequent pipelined branch to execute, but *only if* everything
193 * is still identity mapped. If any mappings change, the pipeline
194 * will flush.
195 */
196 mov %cr0, %eax
197 orl $CR0_PG, %eax
198 mov %eax, %cr0
199
200 /*
201 * At this point paging is enabled, and we are in "compatibility" mode.
202 * We do another far jump to reload %cs with the 64 bit selector.
203 * %cr3 points to a 4-level page table page.
204 * We cannot yet jump all the way to the kernel because we can only
205 * specify a 32 bit linear address. So, yet another trampoline.
206 *
207 * The following instruction is:
208 * ljmp $bootcode64 - bootgdt, $wakeup_64 - wakeup_start
209 * but gas cannot assemble that. And besides, we patch the targets
210 * in early startup and its a little clearer what we are patching.
211 */
212 wakeup_sw64:
213 .byte 0xea /* opcode for far jump */
214 .long wakeup_64 - wakeup_start /* offset in segment */
215 .word bootcode64 - bootgdt /* index in gdt for 64 bit code */
216
217 /*
218 * Yeehar! We're running in 64-bit mode! We can mostly ignore our
219 * segment registers, and get on with it.
220 * Note that we are running at the correct virtual address, but with
221 * a 1:1 1GB mirrored mapping over entire address space. We had better
222 * switch to a real %cr3 promptly so that we can get to the direct map
223 * space. Remember that jmp is relative and that we've been relocated,
224 * so use an indirect jump.
225 */
226 ALIGN_TEXT
227 .code64
228 wakeup_64:
229 mov $bootdata64 - bootgdt, %eax
230 mov %ax, %ds
231
232 /* Restore arguments. */
233 movq wakeup_pcb - wakeup_start(%rbx), %rdi
234 movq wakeup_ret - wakeup_start(%rbx), %rax
235
236 /* Restore GDT. */
237 lgdt wakeup_gdt - wakeup_start(%rbx)
238
239 /* Jump to return address. */
240 jmp *%rax
241
242 .data
243
244 resume_beep:
245 .byte 0
246 reset_video:
247 .byte 0
248
249 ALIGN_DATA
250 bootgdt:
251 .long 0x00000000
252 .long 0x00000000
253 .long 0x00000000
254 .long 0x00000000
255 .long 0x00000000
256 .long 0x00000000
257 .long 0x00000000
258 .long 0x00000000
259
260 bootcode64:
261 .long 0x0000ffff
262 .long 0x00af9b00
263
264 bootdata64:
265 .long 0x0000ffff
266 .long 0x00af9300
267
268 bootcode32:
269 .long 0x0000ffff
270 .long 0x00cf9b00
271
272 bootdata32:
273 .long 0x0000ffff
274 .long 0x00cf9300
275 bootgdtend:
276
277 wakeup_pagetables:
278 .long 0
279
280 bootgdtdesc:
281 .word bootgdtend - bootgdt /* Length */
282 .long bootgdt - wakeup_start /* Offset plus %ds << 4 */
283
284 ALIGN_DATA
285 wakeup_pcb:
286 .quad 0
287 wakeup_ret:
288 .quad 0
289 wakeup_efer:
290 .quad 0
291 wakeup_gdt:
292 .word 0
293 .quad 0
294 dummy:
Cache object: 6f90130fcd0d1a0ed8815022f50983fb
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