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Diffstat (limited to 'src/arch/i386/boot/wakeup.S')
-rw-r--r--src/arch/i386/boot/wakeup.S89
1 files changed, 89 insertions, 0 deletions
diff --git a/src/arch/i386/boot/wakeup.S b/src/arch/i386/boot/wakeup.S
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+/*
+ * 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