diff options
Diffstat (limited to 'src/arch/i386/boot/wakeup.S')
| -rw-r--r-- | src/arch/i386/boot/wakeup.S | 126 |
1 files changed, 70 insertions, 56 deletions
diff --git a/src/arch/i386/boot/wakeup.S b/src/arch/i386/boot/wakeup.S index 7915fc38c5..b348e95a71 100644 --- a/src/arch/i386/boot/wakeup.S +++ b/src/arch/i386/boot/wakeup.S @@ -2,10 +2,11 @@ * This file is part of the coreboot project. * * Copyright (C) 2009 Rudolf Marek <r.marek@assembler.cz> + * Copyright (C) 2009 coresystems GmbH * * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License v2 as published by - * the Free Software Foundation. + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of @@ -16,76 +17,89 @@ * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ - .text - .code32 - .globl acpi_jmp_to_realm_wakeup - /* This function does the PM -> RM switch, but - it can run >1MB even in real mode */ -acpi_jmp_to_realm_wakeup: - mov 0x4(%esp), %eax +#define WAKEUP_BASE 0x600 +#define RELOCATED(x) (x - __wakeup + WAKEUP_BASE) + +/* CR0 bits */ +#define PE (1 << 0) + + .code32 + .globl __wakeup +__wakeup: + /* First prepare the jmp to the resume vector */ + mov 0x4(%esp), %eax /* vector */ /* last 4 bits of linear addr are taken as offset */ andw $0x0f, %ax - movw %ax, (jmp_off) + movw %ax, (__wakeup_offset) mov 0x4(%esp), %eax /* the rest is taken as segment */ shr $4, %eax - movw %ax, (jmp_seg) - lgdt gdtaddr_wakeup - movl $0x008,%eax - mov %eax,%ds - movl %eax,%es - movl %eax,%ss - movl %eax,%fs - movl %eax,%gs - ljmp $0x0010,$reload_cs - .code16gcc -reload_cs: - /* switch off PE */ + movw %ax, (__wakeup_segment) + + /* Then overwrite coreboot with our backed up memory */ + movl 8(%esp), %esi + movl 12(%esp), %edi + movl 16(%esp), %ecx + shrl $4, %ecx +1: + movl 0(%esi),%eax + movl 4(%esi),%edx + movl 8(%esi),%ebx + movl 12(%esi),%ebp + addl $16,%esi + subl $1,%ecx + movl %eax,0(%edi) + movl %edx,4(%edi) + movl %ebx,8(%edi) + movl %ebp,12(%edi) + leal 16(%edi),%edi + jne 1b + + /* Activate the right segment descriptor real mode. */ + ljmp $0x28, $RELOCATED(1f) +1: +.code16 + /* 16 bit code from here on... */ + + /* Load the segment registers w/ properly configured + * segment descriptors. They will retain these + * configurations (limits, writability, etc.) once + * protected mode is turned off. + */ + mov $0x30, %ax + mov %ax, %ds + mov %ax, %es + mov %ax, %fs + mov %ax, %gs + mov %ax, %ss + + /* Turn off protection */ movl %cr0, %eax - andb $0xfe,%al + andl $~PE, %eax movl %eax, %cr0 - ljmpl $0x0, $cpu_flushed -cpu_flushed: + + /* Now really going into real mode */ + ljmp $0, $RELOCATED(1f) +1: movw $0x0, %ax movw %ax, %ds movw %ax, %es movw %ax, %ss movw %ax, %fs movw %ax, %gs - /* far jump to OS waking vector. The linear addr is changed to SEG and OFFSET - check ACPI specs or above code for details */ - .byte 0xea -jmp_off: - .word 0 -jmp_seg: - .word 0 -.code32 -gdt_wakeup_limit = gdt_wakeup_end - gdt_wakeup - 1 /* compute the table limit */ - gdtaddr_wakeup: - .word gdt_wakeup_limit /* the table limit */ - .long gdt_wakeup /* we know the offset */ - - .data - - /* This is the gdt for GCC part of coreboot. - * It is different from the gdt in ROMCC/ASM part of coreboot - * which is defined in entry32.inc */ -gdt_wakeup: - /* selgdt 0, unused */ - .word 0x0000, 0x0000 /* dummy */ - .byte 0x00, 0x00, 0x00, 0x00 + /* This is a FAR JMP to the OS waking vector. The C code changed + * the address to be correct. + */ + .byte 0xea - /* selgdt 8, flat data segment 16bit */ - .word 0x0000, 0x0000 /* dummy */ - .byte 0x00, 0x93, 0x8f, 0x00 /* G=1 and 0x0f, So we get 4Gbytes for limit */ +__wakeup_offset = RELOCATED(.) + .word 0x0000 - /* selgdt 0x10, flat code segment 16bit */ - .word 0xffff, 0x0000 - .byte 0x00, 0x9b, 0x8f, 0x00 /* G=1 and 0x0f, So we get 4Gbytes for limit */ +__wakeup_segment = RELOCATED(.) + .word 0x0000 -gdt_wakeup_end: + .globl __wakeup_size +__wakeup_size = ( . - __wakeup) - .previous -.code32 |