1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
|
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2003,2004 Eric Biederman (ebiederm@xmission.com)
* Copyright (C) 2014 Red Hat Inc.
* Author(s): Vivek Goyal <vgoyal@redhat.com>
*
* This code has been taken from kexec-tools.
*/
#include <linux/linkage.h>
.text
.balign 16
.code64
SYM_CODE_START(entry64)
/* Setup a gdt that should be preserved */
lgdt gdt(%rip)
/* load the data segments */
movl $0x18, %eax /* data segment */
movl %eax, %ds
movl %eax, %es
movl %eax, %ss
movl %eax, %fs
movl %eax, %gs
/* Setup new stack */
leaq stack_init(%rip), %rsp
pushq $0x10 /* CS */
leaq new_cs_exit(%rip), %rax
pushq %rax
lretq
new_cs_exit:
/* Load the registers */
movq rax(%rip), %rax
movq rbx(%rip), %rbx
movq rcx(%rip), %rcx
movq rdx(%rip), %rdx
movq rsi(%rip), %rsi
movq rdi(%rip), %rdi
movq rsp(%rip), %rsp
movq rbp(%rip), %rbp
movq r8(%rip), %r8
movq r9(%rip), %r9
movq r10(%rip), %r10
movq r11(%rip), %r11
movq r12(%rip), %r12
movq r13(%rip), %r13
movq r14(%rip), %r14
movq r15(%rip), %r15
/* Jump to the new code... */
jmpq *rip(%rip)
SYM_CODE_END(entry64)
.section ".rodata"
.balign 4
SYM_DATA_START(entry64_regs)
rax: .quad 0x0
rcx: .quad 0x0
rdx: .quad 0x0
rbx: .quad 0x0
rsp: .quad 0x0
rbp: .quad 0x0
rsi: .quad 0x0
rdi: .quad 0x0
r8: .quad 0x0
r9: .quad 0x0
r10: .quad 0x0
r11: .quad 0x0
r12: .quad 0x0
r13: .quad 0x0
r14: .quad 0x0
r15: .quad 0x0
rip: .quad 0x0
SYM_DATA_END(entry64_regs)
/* GDT */
.section ".rodata"
.balign 16
SYM_DATA_START_LOCAL(gdt)
/*
* 0x00 unusable segment
* 0x08 unused
* so use them as gdt ptr
*/
.word gdt_end - gdt - 1
.quad gdt
.word 0, 0, 0
/* 0x10 4GB flat code segment */
.word 0xFFFF, 0x0000, 0x9A00, 0x00AF
/* 0x18 4GB flat data segment */
.word 0xFFFF, 0x0000, 0x9200, 0x00CF
SYM_DATA_END_LABEL(gdt, SYM_L_LOCAL, gdt_end)
SYM_DATA_START_LOCAL(stack)
.quad 0, 0
SYM_DATA_END_LABEL(stack, SYM_L_LOCAL, stack_init)
|
