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5234f5eb EB |
1 | /* |
2 | * relocate_kernel.S - put the kernel image in place to boot | |
3 | * Copyright (C) 2002-2005 Eric Biederman <ebiederm@xmission.com> | |
4 | * | |
5 | * This source code is licensed under the GNU General Public License, | |
6 | * Version 2. See the file COPYING for more details. | |
7 | */ | |
8 | ||
9 | #include <linux/linkage.h> | |
0341c14d | 10 | #include <asm/page_types.h> |
4bfaaef0 | 11 | #include <asm/kexec.h> |
fd3af531 | 12 | #include <asm/processor-flags.h> |
0341c14d | 13 | #include <asm/pgtable_types.h> |
5234f5eb | 14 | |
4bfaaef0 MD |
15 | /* |
16 | * Must be relocatable PIC code callable as a C function | |
17 | */ | |
18 | ||
19 | #define PTR(x) (x << 3) | |
366932de | 20 | #define PAGE_ATTR (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY) |
4bfaaef0 MD |
21 | |
22 | .text | |
288621e3 | 23 | .align PAGE_SIZE |
5234f5eb | 24 | .code64 |
4bfaaef0 MD |
25 | .globl relocate_kernel |
26 | relocate_kernel: | |
27 | /* %rdi indirection_page | |
28 | * %rsi page_list | |
29 | * %rdx start address | |
30 | */ | |
31 | ||
5234f5eb EB |
32 | /* zero out flags, and disable interrupts */ |
33 | pushq $0 | |
34 | popfq | |
35 | ||
4bfaaef0 MD |
36 | /* get physical address of control page now */ |
37 | /* this is impossible after page table switch */ | |
38 | movq PTR(PA_CONTROL_PAGE)(%rsi), %r8 | |
39 | ||
40 | /* get physical address of page table now too */ | |
41 | movq PTR(PA_TABLE_PAGE)(%rsi), %rcx | |
5234f5eb | 42 | |
f5deb796 HY |
43 | /* Switch to the identity mapped page tables */ |
44 | movq %rcx, %cr3 | |
4bfaaef0 MD |
45 | |
46 | /* setup a new stack at the end of the physical control page */ | |
a7bba17b | 47 | lea PAGE_SIZE(%r8), %rsp |
4bfaaef0 MD |
48 | |
49 | /* jump to identity mapped page */ | |
50 | addq $(identity_mapped - relocate_kernel), %r8 | |
51 | pushq %r8 | |
52 | ret | |
53 | ||
54 | identity_mapped: | |
55 | /* store the start address on the stack */ | |
56 | pushq %rdx | |
5234f5eb EB |
57 | |
58 | /* Set cr0 to a known state: | |
fd3af531 | 59 | * - Paging enabled |
60 | * - Alignment check disabled | |
61 | * - Write protect disabled | |
62 | * - No task switch | |
63 | * - Don't do FP software emulation. | |
64 | * - Proctected mode enabled | |
5234f5eb EB |
65 | */ |
66 | movq %cr0, %rax | |
fd3af531 | 67 | andq $~(X86_CR0_AM | X86_CR0_WP | X86_CR0_TS | X86_CR0_EM), %rax |
68 | orl $(X86_CR0_PG | X86_CR0_PE), %eax | |
5234f5eb EB |
69 | movq %rax, %cr0 |
70 | ||
71 | /* Set cr4 to a known state: | |
fd3af531 | 72 | * - physical address extension enabled |
5234f5eb | 73 | */ |
fd3af531 | 74 | movq $X86_CR4_PAE, %rax |
5234f5eb EB |
75 | movq %rax, %cr4 |
76 | ||
77 | jmp 1f | |
78 | 1: | |
79 | ||
f5deb796 | 80 | /* Flush the TLB (needed?) */ |
5234f5eb EB |
81 | movq %rcx, %cr3 |
82 | ||
83 | /* Do the copies */ | |
84 | movq %rdi, %rcx /* Put the page_list in %rcx */ | |
85 | xorq %rdi, %rdi | |
86 | xorq %rsi, %rsi | |
87 | jmp 1f | |
88 | ||
89 | 0: /* top, read another word for the indirection page */ | |
90 | ||
91 | movq (%rbx), %rcx | |
92 | addq $8, %rbx | |
93 | 1: | |
94 | testq $0x1, %rcx /* is it a destination page? */ | |
95 | jz 2f | |
96 | movq %rcx, %rdi | |
97 | andq $0xfffffffffffff000, %rdi | |
98 | jmp 0b | |
99 | 2: | |
100 | testq $0x2, %rcx /* is it an indirection page? */ | |
101 | jz 2f | |
102 | movq %rcx, %rbx | |
103 | andq $0xfffffffffffff000, %rbx | |
104 | jmp 0b | |
105 | 2: | |
106 | testq $0x4, %rcx /* is it the done indicator? */ | |
107 | jz 2f | |
108 | jmp 3f | |
109 | 2: | |
110 | testq $0x8, %rcx /* is it the source indicator? */ | |
111 | jz 0b /* Ignore it otherwise */ | |
112 | movq %rcx, %rsi /* For ever source page do a copy */ | |
113 | andq $0xfffffffffffff000, %rsi | |
114 | ||
115 | movq $512, %rcx | |
116 | rep ; movsq | |
117 | jmp 0b | |
118 | 3: | |
119 | ||
120 | /* To be certain of avoiding problems with self-modifying code | |
121 | * I need to execute a serializing instruction here. | |
122 | * So I flush the TLB by reloading %cr3 here, it's handy, | |
123 | * and not processor dependent. | |
124 | */ | |
125 | movq %cr3, %rax | |
126 | movq %rax, %cr3 | |
127 | ||
128 | /* set all of the registers to known values */ | |
129 | /* leave %rsp alone */ | |
130 | ||
131 | xorq %rax, %rax | |
132 | xorq %rbx, %rbx | |
133 | xorq %rcx, %rcx | |
134 | xorq %rdx, %rdx | |
135 | xorq %rsi, %rsi | |
136 | xorq %rdi, %rdi | |
137 | xorq %rbp, %rbp | |
138 | xorq %r8, %r8 | |
139 | xorq %r9, %r9 | |
140 | xorq %r10, %r9 | |
141 | xorq %r11, %r11 | |
142 | xorq %r12, %r12 | |
143 | xorq %r13, %r13 | |
144 | xorq %r14, %r14 | |
145 | xorq %r15, %r15 | |
146 | ||
147 | ret |