/* * This file is part of the coreboot project. * * Copyright (C) 2009 Rudolf Marek * * 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 ljmpl $0x0, $cpu_flushed cpu_flushed: 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