diff options
Diffstat (limited to 'src/arch/i386/boot/wakeup.S')
| -rw-r--r-- | src/arch/i386/boot/wakeup.S | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/src/arch/i386/boot/wakeup.S b/src/arch/i386/boot/wakeup.S new file mode 100644 index 0000000000..5985c8e1c0 --- /dev/null +++ b/src/arch/i386/boot/wakeup.S @@ -0,0 +1,89 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2009 Rudolf Marek <r.marek@assembler.cz> + * + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * 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 + /* last 4 bits of linear addr are taken as offset */ + andw $0x0f, %ax + movw %ax, (jmp_off) + 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 */ + movl %cr0, %eax + andb $0xfe,%al + movl %eax, %cr0 + 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 + + /* 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 */ + + /* selgdt 0x10, flat code segment 16bit */ + .word 0xffff, 0x0000 + .byte 0x00, 0x9b, 0x8f, 0x00 /* G=1 and 0x0f, So we get 4Gbytes for limit */ + +gdt_wakeup_end: + + .previous +.code32 |