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.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 /* FIXME This code should be dropped and instead the generic resume code
26 /* Parts of this code is taken from reboot.c from Linux. */
29 * This file mostly copied from Rudolf's S3 patch, some changes in
36 #include <console/console.h>
43 * The following code and data reboots the machine by switching to real
44 * mode and jumping to the BIOS reset entry point, as if the CPU has
45 * really been reset. The previous version asked the keyboard
46 * controller to pulse the CPU reset line, which is more thorough, but
47 * doesn't work with at least one type of 486 motherboard. It is easy
48 * to stop this code working; hence the copious comments.
51 static unsigned long long real_mode_gdt_entries[3] = {
52 0x0000000000000000ULL, /* Null descriptor */
53 0x00009a000000ffffULL, /* 16-bit real-mode 64k code at 0x00000000 */
54 0x000092000100ffffULL /* 16-bit real-mode 64k data at 0x00000100 */
57 struct Xgt_desc_struct {
59 unsigned long address __attribute__ ((packed));
61 } __attribute__ ((packed));
63 static struct Xgt_desc_struct real_mode_gdt = {
64 sizeof(real_mode_gdt_entries) - 1,
65 (long)real_mode_gdt_entries
67 real_mode_idt = {0x3ff, 0},
71 * This is 16-bit protected mode code to disable paging and the cache,
72 * switch to real mode and jump to the BIOS reset code.
74 * The instruction that switches to real mode by writing to CR0 must be
75 * followed immediately by a far jump instruction, which set CS to a
76 * valid value for real mode, and flushes the prefetch queue to avoid
77 * running instructions that have already been decoded in protected
80 * Clears all the flags except ET, especially PG (paging), PE
81 * (protected-mode enable) and TS (task switch for coprocessor state
82 * save). Flushes the TLB after paging has been disabled. Sets CD and
83 * NW, to disable the cache on a 486, and invalidates the cache. This
84 * is more like the state of a 486 after reset. I don't know if
85 * something else should be done for other chips.
87 * More could be done here to set up the registers as if a CPU reset had
88 * occurred; hopefully real BIOSs don't assume much.
91 // 0x66, 0x0d, 0x00, 0x00, 0x00, 0x60, /* orl $0x60000000, %eax */
93 static unsigned char real_mode_switch[] = {
94 0x66, 0x0f, 0x20, 0xc0, /* movl %cr0,%eax */
95 0x24, 0xfe, /* andb $0xfe,al */
96 0x66, 0x0f, 0x22, 0xc0 /* movl %eax,%cr0 */
99 static unsigned char jump_to_wakeup[] = {
100 0xea, 0x00, 0x00, 0x00, 0xe0 /* ljmp $0xffff, $0x0000 */
103 void acpi_jump_wake(u32 vector)
106 struct Xgt_desc_struct *wake_thunk16_Xgt_desc;
108 printk(BIOS_DEBUG, "IN ACPI JUMP WAKE TO %x\n", vector);
110 die("failed to enable A20\n");
111 printk(BIOS_DEBUG, "IN ACPI JUMP WAKE TO 3 %x\n", vector);
113 *((u16 *) (jump_to_wakeup + 3)) = (u16) (vector >> 4);
114 printk(BIOS_DEBUG, "%x %x %x %x %x\n", jump_to_wakeup[0], jump_to_wakeup[1],
115 jump_to_wakeup[2], jump_to_wakeup[3], jump_to_wakeup[4]);
117 memcpy((void *)(WAKE_THUNK16_ADDR - sizeof(real_mode_switch) - 100),
118 real_mode_switch, sizeof(real_mode_switch));
119 memcpy((void *)(WAKE_THUNK16_ADDR - 100), jump_to_wakeup,
120 sizeof(jump_to_wakeup));
123 printk(BIOS_EMERG, "file '%s', line %d\n\n", __FILE__, __LINE__);
124 //jason_tsc_count_end();
126 unsigned long long *real_mode_gdt_entries_at_eseg;
127 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; */
128 real_mode_gdt_entries_at_eseg[0] = 0x0000000000000000ULL; /* Null descriptor */
129 real_mode_gdt_entries_at_eseg[1] = 0x000f9a000000ffffULL; /* 16-bit real-mode 1M code at 0x00000000 */
130 real_mode_gdt_entries_at_eseg[2] = 0x000f93000000ffffULL; /* 16-bit real-mode 1M data at 0x00000000 */
132 wake_thunk16_Xgt_desc = (void *)WAKE_THUNK16_XDTR;
133 wake_thunk16_Xgt_desc[0].size = sizeof(real_mode_gdt_entries) - 1;
134 wake_thunk16_Xgt_desc[0].address = (long)real_mode_gdt_entries_at_eseg;
135 wake_thunk16_Xgt_desc[1].size = 0x3ff;
136 wake_thunk16_Xgt_desc[1].address = 0;
137 wake_thunk16_Xgt_desc[2].size = 0;
138 wake_thunk16_Xgt_desc[2].address = 0;
140 /* Added this code to get current value of EIP. */
148 unsigned char *dest, *src;
149 src = (unsigned char *)dwEip;
150 dest = (void *)WAKE_RECOVER1M_CODE;
152 for (i = 0; i < 0x200; i++)
155 __asm__ __volatile__("ljmp $0x0010,%0" /* 08 error */
156 ::"i"((void *)(WAKE_RECOVER1M_CODE + 0x20)));
158 /* Added 0x20 "nop" to make sure the ljmp will not jump then halt. */
159 asm volatile ("nop");
160 asm volatile ("nop");
161 asm volatile ("nop");
162 asm volatile ("nop");
163 asm volatile ("nop");
164 asm volatile ("nop");
165 asm volatile ("nop");
166 asm volatile ("nop");
167 asm volatile ("nop");
168 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");
176 asm volatile ("nop");
177 asm volatile ("nop");
178 asm volatile ("nop");
179 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");
187 asm volatile ("nop");
188 asm volatile ("nop");
189 asm volatile ("nop");
190 asm volatile ("nop");
194 * Set new esp, maybe ebp should not equal to esp?, due to the
195 * variable in acpi_jump_wake?, anyway, this may be not a big
196 * problem. and I didn't clear the area (ef000+-0x200) to zero.
199 "movl %0, %%esp\n\t"::"a" (WAKE_THUNK16_STACK)
203 * Only "src" and "dest" use the new stack, and the esp maybe also
204 * used in resumevector.
206 #if PAYLOAD_IS_SEABIOS == 1
207 /* WAKE_MEM_INFO inited in get_set_top_available_mem in tables.c. */
209 (unsigned char *)((*(u32 *) WAKE_MEM_INFO) - 64 * 1024 - 0x100000);
213 * If recovered 0-e0000, then when resume, before WinXP turn on the
214 * desktop screen, there is gray background which last 1sec.
216 for (i = 0; i < 0xa0000; i++)
223 "movl $0xa0000, %%ecx\n\t"
229 src = (unsigned char *)((*(u32 *) WAKE_MEM_INFO) - 64 * 1024
230 - 0x100000 + 0xc0000);
234 for (i = 0; i < 0x20000; i++)
239 "movl $0xc0000, %%edi\n\t"
240 "movl $0x20000, %%ecx\n\t"
247 src = (unsigned char *)((*(u32 *) WAKE_MEM_INFO) - 64 * 1024
248 - 0x100000 + 0xe0000 + WAKE_SPECIAL_SIZE);
250 /* dest = 0xf0000; */
251 /* for (i = 0; i < 0x10000; i++) */
252 /* dest[i] = src[i]; */
258 "rep movsd\n\t"::"r" (src),
259 "r"(0xe0000 + WAKE_SPECIAL_SIZE),
260 "r"(0x10000 - WAKE_SPECIAL_SIZE)
263 src = (unsigned char *)((*(u32 *) WAKE_MEM_INFO) - 64 * 1024
264 - 0x100000 + 0xf0000);
265 /* dest = 0xf0000; */
266 /* for (i = 0; i < 0x10000; i++) */
267 /* dest[i] = src[i]; */
270 "movl $0xf0000, %%edi\n\t"
271 "movl $0x10000, %%ecx\n\t"
272 "shrl $2, %%ecx\n\t" "rep movsd\n\t"::"a" (src)
275 asm volatile ("wbinvd");
277 /* Set up the IDT for real mode. */
278 asm volatile ("lidt %0"::"m" (wake_thunk16_Xgt_desc[1]));
281 * Set up a GDT from which we can load segment descriptors for real
282 * mode. The GDT is not used in real mode; it is just needed here to
283 * prepare the descriptors.
285 asm volatile ("lgdt %0"::"m" (wake_thunk16_Xgt_desc[0]));
288 * Load the data segment registers, and thus the descriptors ready for
289 * real mode. The base address of each segment is 0x100, 16 times the
290 * selector value being loaded here. This is so that the segment
291 * registers don't have to be reloaded after switching to real mode:
292 * the values are consistent for real mode operation already.
294 __asm__ __volatile__(
295 "movl $0x0010,%%eax\n"
296 "\tmovl %%eax,%%ds\n"
297 "\tmovl %%eax,%%es\n"
298 "\tmovl %%eax,%%fs\n"
299 "\tmovl %%eax,%%gs\n"
300 "\tmovl %%eax,%%ss":::"eax"
304 * Jump to the 16-bit code that we copied earlier. It disables paging
305 * and the cache, switches to real mode, and jumps to the BIOS reset
309 __asm__ __volatile__(
310 "ljmp $0x0008,%0"::"i"
311 ((void *)(WAKE_THUNK16_ADDR - sizeof(real_mode_switch) - 100))
315 /* -*- linux-c -*- ------------------------------------------------------- *
317 * Copyright (C) 1991, 1992 Linus Torvalds
318 * Copyright 2007 rPath, Inc. - All Rights Reserved
320 * This file is part of the Linux kernel, and is made available under
321 * the terms of the GNU General Public License version 2.
323 * ----------------------------------------------------------------------- */
326 * arch/x86/boot/a20.c
328 * Enable A20 gate (return -1 on failure)
331 #define MAX_8042_LOOPS 100000
333 static int empty_8042(void)
336 int loops = MAX_8042_LOOPS;
343 /* Read and discard input data */
346 } else if (!(status & 2)) {
347 /* Buffers empty, finished! */
355 /* Returns nonzero if the A20 line is enabled. The memory address
356 used as a test is the int $0x80 vector, which should be safe. */
358 #define A20_TEST_ADDR (4*0x80)
359 #define A20_TEST_SHORT 32
360 #define A20_TEST_LONG 2097152 /* 2^21 */
362 static int a20_test(int loops)
367 saved = ctr = *((u32 *) A20_TEST_ADDR);
371 *((u32 *) A20_TEST_ADDR) = ++ctr;
373 udelay(1); /* Serialize and make delay constant */
375 ok = *((u32 *) A20_TEST_ADDR + 0xffff0 + 0x10) ^ ctr;
380 *((u32 *) A20_TEST_ADDR) = saved;
384 /* Quick test to see if A20 is already enabled */
385 static int a20_test_short(void)
387 return a20_test(A20_TEST_SHORT);
390 /* Longer test that actually waits for A20 to come on line; this
391 is useful when dealing with the KBC or other slow external circuitry. */
392 static int a20_test_long(void)
394 return a20_test(A20_TEST_LONG);
397 static void enable_a20_kbc(void)
401 outb(0xd1, 0x64); /* Command write */
404 outb(0xdf, 0x60); /* A20 on */
408 static void enable_a20_fast(void)
412 port_a = inb(0x92); /* Configuration port A */
413 port_a |= 0x02; /* Enable A20 */
414 port_a &= ~0x01; /* Do not reset machine */
419 * Actual routine to enable A20; return 0 on ok, -1 on failure
422 #define A20_ENABLE_LOOPS 255 /* Number of times to try */
426 int loops = A20_ENABLE_LOOPS;
429 /* First, check to see if A20 is already enabled
430 (legacy free, etc.) */
431 if (a20_test_short())
434 /* Try enabling A20 through the keyboard controller */
437 // if (a20_test_short())
438 // return 0; /* BIOS worked, but with delayed reaction */
444 /* Finally, try enabling the "fast A20 gate" */