projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 7052fdd8 PA |
1 | /* ----------------------------------------------------------------------- * |
| 2 | * | |
| 3 | * Copyright (C) 1991, 1992 Linus Torvalds | |
| 4 | * Copyright 2007 rPath, Inc. - All Rights Reserved | |
| 5 | * | |
| 6 | * This file is part of the Linux kernel, and is made available under | |
| 7 | * the terms of the GNU General Public License version 2. | |
| 8 | * | |
| 9 | * ----------------------------------------------------------------------- */ | |
| 10 | ||
| 11 | /* | |
| 12 | * arch/i386/boot/pmjump.S | |
| 13 | * | |
| 14 | * The actual transition into protected mode | |
| 15 | */ | |
| 16 | ||
| 17 | #include <asm/boot.h> | |
| 18 | #include <asm/segment.h> | |
| 19 | ||
| 20 | .text | |
| 21 | ||
| 22 | .globl protected_mode_jump | |
| 23 | .type protected_mode_jump, @function | |
| 24 | ||
| 25 | .code16 | |
| 26 | ||
| 27 | /* | |
| 28 | * void protected_mode_jump(u32 entrypoint, u32 bootparams); | |
| 29 | */ | |
| 30 | protected_mode_jump: | |
| 7052fdd8 PA |
31 | movl %edx, %esi # Pointer to boot_params table |
| 32 | movl %eax, 2f # Patch ljmpl instruction | |
| 7052fdd8 | 33 | |
| 7052fdd8 | 34 | movw $__BOOT_DS, %cx |
| 9f259cc5 PA |
35 | xorl %ebx, %ebx # Per the 32-bit boot protocol |
| 36 | xorl %ebp, %ebp # Per the 32-bit boot protocol | |
| 37 | xorl %edi, %edi # Per the 32-bit boot protocol | |
| 7052fdd8 PA |
38 | |
| 39 | movl %cr0, %edx | |
| 40 | orb $1, %dl # Protected mode (PE) bit | |
| 41 | movl %edx, %cr0 | |
| 7ed19290 PA |
42 | jmp 1f # Short jump to serialize on 386/486 |
| 43 | 1: | |
| 7052fdd8 PA |
44 | |
| 45 | movw %cx, %ds | |
| 46 | movw %cx, %es | |
| 47 | movw %cx, %fs | |
| 48 | movw %cx, %gs | |
| 49 | movw %cx, %ss | |
| 50 | ||
| 51 | # Jump to the 32-bit entrypoint | |
| 52 | .byte 0x66, 0xea # ljmpl opcode | |
| 53 | 2: .long 0 # offset | |
| 54 | .word __BOOT_CS # segment | |
| 55 | ||
| 56 | .size protected_mode_jump, .-protected_mode_jump |