2 * This file is part of the coreboot project.
4 * Copyright (C) 2008 Rudolf Marek <r.marek@assembler.cz>
5 * Copyright (C) 2009 One Laptop per Child, Association, Inc.
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
18 /* FIXME This code should be dropped and instead the generic resume code
22 /* Parts of this code is taken from reboot.c from Linux. */
25 * This file mostly copied from Rudolf's S3 patch, some changes in
32 #include <console/console.h>
39 * The following code and data reboots the machine by switching to real
40 * mode and jumping to the BIOS reset entry point, as if the CPU has
41 * really been reset. The previous version asked the keyboard
42 * controller to pulse the CPU reset line, which is more thorough, but
43 * doesn't work with at least one type of 486 motherboard. It is easy
44 * to stop this code working; hence the copious comments.
47 static unsigned long long real_mode_gdt_entries
[3] = {
48 0x0000000000000000ULL
, /* Null descriptor */
49 0x00009a000000ffffULL
, /* 16-bit real-mode 64k code at 0x00000000 */
50 0x000092000100ffffULL
/* 16-bit real-mode 64k data at 0x00000100 */
53 struct Xgt_desc_struct
{
55 unsigned long address
__attribute__ ((packed
));
57 } __attribute__ ((packed
));
59 static struct Xgt_desc_struct real_mode_gdt
= {
60 sizeof(real_mode_gdt_entries
) - 1,
61 (long)real_mode_gdt_entries
63 real_mode_idt
= {0x3ff, 0},
67 * This is 16-bit protected mode code to disable paging and the cache,
68 * switch to real mode and jump to the BIOS reset code.
70 * The instruction that switches to real mode by writing to CR0 must be
71 * followed immediately by a far jump instruction, which set CS to a
72 * valid value for real mode, and flushes the prefetch queue to avoid
73 * running instructions that have already been decoded in protected
76 * Clears all the flags except ET, especially PG (paging), PE
77 * (protected-mode enable) and TS (task switch for coprocessor state
78 * save). Flushes the TLB after paging has been disabled. Sets CD and
79 * NW, to disable the cache on a 486, and invalidates the cache. This
80 * is more like the state of a 486 after reset. I don't know if
81 * something else should be done for other chips.
83 * More could be done here to set up the registers as if a CPU reset had
84 * occurred; hopefully real BIOSs don't assume much.
87 // 0x66, 0x0d, 0x00, 0x00, 0x00, 0x60, /* orl $0x60000000, %eax */
89 static unsigned char real_mode_switch
[] = {
90 0x66, 0x0f, 0x20, 0xc0, /* movl %cr0,%eax */
91 0x24, 0xfe, /* andb $0xfe,al */
92 0x66, 0x0f, 0x22, 0xc0 /* movl %eax,%cr0 */
95 static unsigned char jump_to_wakeup
[] = {
96 0xea, 0x00, 0x00, 0x00, 0xe0 /* ljmp $0xffff, $0x0000 */
99 void acpi_jump_wake(u32 vector
)
102 struct Xgt_desc_struct
*wake_thunk16_Xgt_desc
;
104 printk(BIOS_DEBUG
, "IN ACPI JUMP WAKE TO %x\n", vector
);
106 die("failed to enable A20\n");
107 printk(BIOS_DEBUG
, "IN ACPI JUMP WAKE TO 3 %x\n", vector
);
109 *((u16
*) (jump_to_wakeup
+ 3)) = (u16
) (vector
>> 4);
110 printk(BIOS_DEBUG
, "%x %x %x %x %x\n", jump_to_wakeup
[0], jump_to_wakeup
[1],
111 jump_to_wakeup
[2], jump_to_wakeup
[3], jump_to_wakeup
[4]);
113 memcpy((void *)(WAKE_THUNK16_ADDR
- sizeof(real_mode_switch
) - 100),
114 real_mode_switch
, sizeof(real_mode_switch
));
115 memcpy((void *)(WAKE_THUNK16_ADDR
- 100), jump_to_wakeup
,
116 sizeof(jump_to_wakeup
));
119 printk(BIOS_EMERG
, "file '%s', line %d\n\n", __FILE__
, __LINE__
);
120 //jason_tsc_count_end();
122 unsigned long long *real_mode_gdt_entries_at_eseg
;
123 real_mode_gdt_entries_at_eseg
= (void *)WAKE_THUNK16_GDT
; /* Copy from real_mode_gdt_entries and change limition to 1M and data base to 0; */
124 real_mode_gdt_entries_at_eseg
[0] = 0x0000000000000000ULL
; /* Null descriptor */
125 real_mode_gdt_entries_at_eseg
[1] = 0x000f9a000000ffffULL
; /* 16-bit real-mode 1M code at 0x00000000 */
126 real_mode_gdt_entries_at_eseg
[2] = 0x000f93000000ffffULL
; /* 16-bit real-mode 1M data at 0x00000000 */
128 wake_thunk16_Xgt_desc
= (void *)WAKE_THUNK16_XDTR
;
129 wake_thunk16_Xgt_desc
[0].size
= sizeof(real_mode_gdt_entries
) - 1;
130 wake_thunk16_Xgt_desc
[0].address
= (long)real_mode_gdt_entries_at_eseg
;
131 wake_thunk16_Xgt_desc
[1].size
= 0x3ff;
132 wake_thunk16_Xgt_desc
[1].address
= 0;
133 wake_thunk16_Xgt_desc
[2].size
= 0;
134 wake_thunk16_Xgt_desc
[2].address
= 0;
136 /* Added this code to get current value of EIP. */
144 unsigned char *dest
, *src
;
145 src
= (unsigned char *)dwEip
;
146 dest
= (void *)WAKE_RECOVER1M_CODE
;
148 for (i
= 0; i
< 0x200; i
++)
151 __asm__
__volatile__("ljmp $0x0010,%0" /* 08 error */
152 ::"i"((void *)(WAKE_RECOVER1M_CODE
+ 0x20)));
154 /* Added 0x20 "nop" to make sure the ljmp will not jump then halt. */
155 asm volatile ("nop");
156 asm volatile ("nop");
157 asm volatile ("nop");
158 asm volatile ("nop");
159 asm volatile ("nop");
160 asm volatile ("nop");
161 asm volatile ("nop");
162 asm volatile ("nop");
163 asm volatile ("nop");
164 asm volatile ("nop");
166 asm volatile ("nop");
167 asm volatile ("nop");
168 asm volatile ("nop");
169 asm volatile ("nop");
170 asm volatile ("nop");
171 asm volatile ("nop");
172 asm volatile ("nop");
173 asm volatile ("nop");
174 asm volatile ("nop");
175 asm volatile ("nop");
177 asm volatile ("nop");
178 asm volatile ("nop");
179 asm volatile ("nop");
180 asm volatile ("nop");
181 asm volatile ("nop");
182 asm volatile ("nop");
183 asm volatile ("nop");
184 asm volatile ("nop");
185 asm volatile ("nop");
186 asm volatile ("nop");
190 * Set new esp, maybe ebp should not equal to esp?, due to the
191 * variable in acpi_jump_wake?, anyway, this may be not a big
192 * problem. and I didn't clear the area (ef000+-0x200) to zero.
195 "movl %0, %%esp\n\t"::"a" (WAKE_THUNK16_STACK
)
199 * Only "src" and "dest" use the new stack, and the esp maybe also
200 * used in resumevector.
202 #if PAYLOAD_IS_SEABIOS == 1
203 /* WAKE_MEM_INFO inited in get_set_top_available_mem in tables.c. */
205 (unsigned char *)((*(u32
*) WAKE_MEM_INFO
) - 64 * 1024 - 0x100000);
209 * If recovered 0-e0000, then when resume, before WinXP turn on the
210 * desktop screen, there is gray background which last 1sec.
212 for (i
= 0; i
< 0xa0000; i
++)
219 "movl $0xa0000, %%ecx\n\t"
225 src
= (unsigned char *)((*(u32
*) WAKE_MEM_INFO
) - 64 * 1024
226 - 0x100000 + 0xc0000);
230 for (i
= 0; i
< 0x20000; i
++)
235 "movl $0xc0000, %%edi\n\t"
236 "movl $0x20000, %%ecx\n\t"
243 src
= (unsigned char *)((*(u32
*) WAKE_MEM_INFO
) - 64 * 1024
244 - 0x100000 + 0xe0000 + WAKE_SPECIAL_SIZE
);
246 /* dest = 0xf0000; */
247 /* for (i = 0; i < 0x10000; i++) */
248 /* dest[i] = src[i]; */
254 "rep movsd\n\t"::"r" (src
),
255 "r"(0xe0000 + WAKE_SPECIAL_SIZE
),
256 "r"(0x10000 - WAKE_SPECIAL_SIZE
)
259 src
= (unsigned char *)((*(u32
*) WAKE_MEM_INFO
) - 64 * 1024
260 - 0x100000 + 0xf0000);
261 /* dest = 0xf0000; */
262 /* for (i = 0; i < 0x10000; i++) */
263 /* dest[i] = src[i]; */
266 "movl $0xf0000, %%edi\n\t"
267 "movl $0x10000, %%ecx\n\t"
268 "shrl $2, %%ecx\n\t" "rep movsd\n\t"::"a" (src
)
271 asm volatile ("wbinvd");
273 /* Set up the IDT for real mode. */
274 asm volatile ("lidt %0"::"m" (wake_thunk16_Xgt_desc
[1]));
277 * Set up a GDT from which we can load segment descriptors for real
278 * mode. The GDT is not used in real mode; it is just needed here to
279 * prepare the descriptors.
281 asm volatile ("lgdt %0"::"m" (wake_thunk16_Xgt_desc
[0]));
284 * Load the data segment registers, and thus the descriptors ready for
285 * real mode. The base address of each segment is 0x100, 16 times the
286 * selector value being loaded here. This is so that the segment
287 * registers don't have to be reloaded after switching to real mode:
288 * the values are consistent for real mode operation already.
290 __asm__
__volatile__(
291 "movl $0x0010,%%eax\n"
292 "\tmovl %%eax,%%ds\n"
293 "\tmovl %%eax,%%es\n"
294 "\tmovl %%eax,%%fs\n"
295 "\tmovl %%eax,%%gs\n"
296 "\tmovl %%eax,%%ss":::"eax"
300 * Jump to the 16-bit code that we copied earlier. It disables paging
301 * and the cache, switches to real mode, and jumps to the BIOS reset
305 __asm__
__volatile__(
306 "ljmp $0x0008,%0"::"i"
307 ((void *)(WAKE_THUNK16_ADDR
- sizeof(real_mode_switch
) - 100))
311 /* -*- linux-c -*- ------------------------------------------------------- *
313 * Copyright (C) 1991, 1992 Linus Torvalds
314 * Copyright 2007 rPath, Inc. - All Rights Reserved
316 * This file is part of the Linux kernel, and is made available under
317 * the terms of the GNU General Public License version 2.
319 * ----------------------------------------------------------------------- */
322 * arch/x86/boot/a20.c
324 * Enable A20 gate (return -1 on failure)
327 #define MAX_8042_LOOPS 100000
329 static int empty_8042(void)
332 int loops
= MAX_8042_LOOPS
;
339 /* Read and discard input data */
342 } else if (!(status
& 2)) {
343 /* Buffers empty, finished! */
351 /* Returns nonzero if the A20 line is enabled. The memory address
352 used as a test is the int $0x80 vector, which should be safe. */
354 #define A20_TEST_ADDR (4*0x80)
355 #define A20_TEST_SHORT 32
356 #define A20_TEST_LONG 2097152 /* 2^21 */
358 static int a20_test(int loops
)
363 saved
= ctr
= *((u32
*) A20_TEST_ADDR
);
367 *((u32
*) A20_TEST_ADDR
) = ++ctr
;
369 udelay(1); /* Serialize and make delay constant */
371 ok
= *((u32
*) A20_TEST_ADDR
+ 0xffff0 + 0x10) ^ ctr
;
376 *((u32
*) A20_TEST_ADDR
) = saved
;
380 /* Quick test to see if A20 is already enabled */
381 static int a20_test_short(void)
383 return a20_test(A20_TEST_SHORT
);
386 /* Longer test that actually waits for A20 to come on line; this
387 is useful when dealing with the KBC or other slow external circuitry. */
388 static int a20_test_long(void)
390 return a20_test(A20_TEST_LONG
);
393 static void enable_a20_kbc(void)
397 outb(0xd1, 0x64); /* Command write */
400 outb(0xdf, 0x60); /* A20 on */
404 static void enable_a20_fast(void)
408 port_a
= inb(0x92); /* Configuration port A */
409 port_a
|= 0x02; /* Enable A20 */
410 port_a
&= ~0x01; /* Do not reset machine */
415 * Actual routine to enable A20; return 0 on ok, -1 on failure
418 #define A20_ENABLE_LOOPS 255 /* Number of times to try */
422 int loops
= A20_ENABLE_LOOPS
;
425 /* First, check to see if A20 is already enabled
426 (legacy free, etc.) */
427 if (a20_test_short())
430 /* Try enabling A20 through the keyboard controller */
433 // if (a20_test_short())
434 // return 0; /* BIOS worked, but with delayed reaction */
440 /* Finally, try enabling the "fast A20 gate" */