blob: fe3c91ba1bd0c6fd0fe0c880510364dbda0fa5c5 [file] [log] [blame]
Vivek Goyal8fc5b4d2014-08-08 14:26:02 -07001/*
2 * purgatory: setup code
3 *
4 * Copyright (C) 2003,2004 Eric Biederman (ebiederm@xmission.com)
5 * Copyright (C) 2014 Red Hat Inc.
6 *
7 * This code has been taken from kexec-tools.
8 *
9 * This source code is licensed under the GNU General Public License,
10 * Version 2. See the file COPYING for more details.
11 */
12
13 .text
14 .globl purgatory_start
15 .balign 16
16purgatory_start:
17 .code64
18
19 /* Load a gdt so I know what the segment registers are */
20 lgdt gdt(%rip)
21
22 /* load the data segments */
23 movl $0x18, %eax /* data segment */
24 movl %eax, %ds
25 movl %eax, %es
26 movl %eax, %ss
27 movl %eax, %fs
28 movl %eax, %gs
29
30 /* Setup a stack */
31 leaq lstack_end(%rip), %rsp
32
33 /* Call the C code */
34 call purgatory
35 jmp entry64
36
37 .section ".rodata"
38 .balign 16
39gdt: /* 0x00 unusable segment
40 * 0x08 unused
41 * so use them as the gdt ptr
42 */
43 .word gdt_end - gdt - 1
44 .quad gdt
45 .word 0, 0, 0
46
47 /* 0x10 4GB flat code segment */
48 .word 0xFFFF, 0x0000, 0x9A00, 0x00AF
49
50 /* 0x18 4GB flat data segment */
51 .word 0xFFFF, 0x0000, 0x9200, 0x00CF
52gdt_end:
53
54 .bss
55 .balign 4096
56lstack:
57 .skip 4096
58lstack_end: