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1 | /* |
2 | * relocate_kernel.S - put the kernel image in place to boot | |
3 | * Copyright (C) 2002-2004 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> | |
3566561b MD |
10 | #include <asm/page.h> |
11 | #include <asm/kexec.h> | |
12 | ||
13 | /* | |
14 | * Must be relocatable PIC code callable as a C function | |
15 | */ | |
16 | ||
17 | #define PTR(x) (x << 2) | |
18 | #define PAGE_ALIGNED (1 << PAGE_SHIFT) | |
19 | #define PAGE_ATTR 0x63 /* _PAGE_PRESENT|_PAGE_RW|_PAGE_ACCESSED|_PAGE_DIRTY */ | |
20 | #define PAE_PGD_ATTR 0x01 /* _PAGE_PRESENT */ | |
21 | ||
22 | .text | |
23 | .align PAGE_ALIGNED | |
24 | .globl relocate_kernel | |
25 | relocate_kernel: | |
26 | movl 8(%esp), %ebp /* list of pages */ | |
27 | ||
28 | #ifdef CONFIG_X86_PAE | |
29 | /* map the control page at its virtual address */ | |
30 | ||
31 | movl PTR(VA_PGD)(%ebp), %edi | |
32 | movl PTR(VA_CONTROL_PAGE)(%ebp), %eax | |
33 | andl $0xc0000000, %eax | |
34 | shrl $27, %eax | |
35 | addl %edi, %eax | |
36 | ||
37 | movl PTR(PA_PMD_0)(%ebp), %edx | |
38 | orl $PAE_PGD_ATTR, %edx | |
39 | movl %edx, (%eax) | |
40 | ||
41 | movl PTR(VA_PMD_0)(%ebp), %edi | |
42 | movl PTR(VA_CONTROL_PAGE)(%ebp), %eax | |
43 | andl $0x3fe00000, %eax | |
44 | shrl $18, %eax | |
45 | addl %edi, %eax | |
46 | ||
47 | movl PTR(PA_PTE_0)(%ebp), %edx | |
48 | orl $PAGE_ATTR, %edx | |
49 | movl %edx, (%eax) | |
50 | ||
51 | movl PTR(VA_PTE_0)(%ebp), %edi | |
52 | movl PTR(VA_CONTROL_PAGE)(%ebp), %eax | |
53 | andl $0x001ff000, %eax | |
54 | shrl $9, %eax | |
55 | addl %edi, %eax | |
56 | ||
57 | movl PTR(PA_CONTROL_PAGE)(%ebp), %edx | |
58 | orl $PAGE_ATTR, %edx | |
59 | movl %edx, (%eax) | |
60 | ||
61 | /* identity map the control page at its physical address */ | |
62 | ||
63 | movl PTR(VA_PGD)(%ebp), %edi | |
64 | movl PTR(PA_CONTROL_PAGE)(%ebp), %eax | |
65 | andl $0xc0000000, %eax | |
66 | shrl $27, %eax | |
67 | addl %edi, %eax | |
68 | ||
69 | movl PTR(PA_PMD_1)(%ebp), %edx | |
70 | orl $PAE_PGD_ATTR, %edx | |
71 | movl %edx, (%eax) | |
72 | ||
73 | movl PTR(VA_PMD_1)(%ebp), %edi | |
74 | movl PTR(PA_CONTROL_PAGE)(%ebp), %eax | |
75 | andl $0x3fe00000, %eax | |
76 | shrl $18, %eax | |
77 | addl %edi, %eax | |
78 | ||
79 | movl PTR(PA_PTE_1)(%ebp), %edx | |
80 | orl $PAGE_ATTR, %edx | |
81 | movl %edx, (%eax) | |
82 | ||
83 | movl PTR(VA_PTE_1)(%ebp), %edi | |
84 | movl PTR(PA_CONTROL_PAGE)(%ebp), %eax | |
85 | andl $0x001ff000, %eax | |
86 | shrl $9, %eax | |
87 | addl %edi, %eax | |
88 | ||
89 | movl PTR(PA_CONTROL_PAGE)(%ebp), %edx | |
90 | orl $PAGE_ATTR, %edx | |
91 | movl %edx, (%eax) | |
92 | #else | |
93 | /* map the control page at its virtual address */ | |
94 | ||
95 | movl PTR(VA_PGD)(%ebp), %edi | |
96 | movl PTR(VA_CONTROL_PAGE)(%ebp), %eax | |
97 | andl $0xffc00000, %eax | |
98 | shrl $20, %eax | |
99 | addl %edi, %eax | |
100 | ||
101 | movl PTR(PA_PTE_0)(%ebp), %edx | |
102 | orl $PAGE_ATTR, %edx | |
103 | movl %edx, (%eax) | |
104 | ||
105 | movl PTR(VA_PTE_0)(%ebp), %edi | |
106 | movl PTR(VA_CONTROL_PAGE)(%ebp), %eax | |
107 | andl $0x003ff000, %eax | |
108 | shrl $10, %eax | |
109 | addl %edi, %eax | |
110 | ||
111 | movl PTR(PA_CONTROL_PAGE)(%ebp), %edx | |
112 | orl $PAGE_ATTR, %edx | |
113 | movl %edx, (%eax) | |
114 | ||
115 | /* identity map the control page at its physical address */ | |
116 | ||
117 | movl PTR(VA_PGD)(%ebp), %edi | |
118 | movl PTR(PA_CONTROL_PAGE)(%ebp), %eax | |
119 | andl $0xffc00000, %eax | |
120 | shrl $20, %eax | |
121 | addl %edi, %eax | |
122 | ||
123 | movl PTR(PA_PTE_1)(%ebp), %edx | |
124 | orl $PAGE_ATTR, %edx | |
125 | movl %edx, (%eax) | |
126 | ||
127 | movl PTR(VA_PTE_1)(%ebp), %edi | |
128 | movl PTR(PA_CONTROL_PAGE)(%ebp), %eax | |
129 | andl $0x003ff000, %eax | |
130 | shrl $10, %eax | |
131 | addl %edi, %eax | |
132 | ||
133 | movl PTR(PA_CONTROL_PAGE)(%ebp), %edx | |
134 | orl $PAGE_ATTR, %edx | |
135 | movl %edx, (%eax) | |
136 | #endif | |
5033cba0 | 137 | |
5033cba0 EB |
138 | relocate_new_kernel: |
139 | /* read the arguments and say goodbye to the stack */ | |
140 | movl 4(%esp), %ebx /* page_list */ | |
3566561b | 141 | movl 8(%esp), %ebp /* list of pages */ |
5033cba0 EB |
142 | movl 12(%esp), %edx /* start address */ |
143 | movl 16(%esp), %ecx /* cpu_has_pae */ | |
144 | ||
145 | /* zero out flags, and disable interrupts */ | |
146 | pushl $0 | |
147 | popfl | |
148 | ||
3566561b MD |
149 | /* get physical address of control page now */ |
150 | /* this is impossible after page table switch */ | |
151 | movl PTR(PA_CONTROL_PAGE)(%ebp), %edi | |
5033cba0 | 152 | |
3566561b MD |
153 | /* switch to new set of page tables */ |
154 | movl PTR(PA_PGD)(%ebp), %eax | |
155 | movl %eax, %cr3 | |
156 | ||
157 | /* setup a new stack at the end of the physical control page */ | |
158 | lea 4096(%edi), %esp | |
159 | ||
160 | /* jump to identity mapped page */ | |
161 | movl %edi, %eax | |
162 | addl $(identity_mapped - relocate_kernel), %eax | |
163 | pushl %eax | |
164 | ret | |
165 | ||
166 | identity_mapped: | |
167 | /* store the start address on the stack */ | |
168 | pushl %edx | |
5033cba0 EB |
169 | |
170 | /* Set cr0 to a known state: | |
171 | * 31 0 == Paging disabled | |
172 | * 18 0 == Alignment check disabled | |
173 | * 16 0 == Write protect disabled | |
174 | * 3 0 == No task switch | |
175 | * 2 0 == Don't do FP software emulation. | |
176 | * 0 1 == Proctected mode enabled | |
177 | */ | |
178 | movl %cr0, %eax | |
179 | andl $~((1<<31)|(1<<18)|(1<<16)|(1<<3)|(1<<2)), %eax | |
180 | orl $(1<<0), %eax | |
181 | movl %eax, %cr0 | |
182 | ||
183 | /* clear cr4 if applicable */ | |
184 | testl %ecx, %ecx | |
185 | jz 1f | |
186 | /* Set cr4 to a known state: | |
187 | * Setting everything to zero seems safe. | |
188 | */ | |
189 | movl %cr4, %eax | |
190 | andl $0, %eax | |
191 | movl %eax, %cr4 | |
192 | ||
193 | jmp 1f | |
194 | 1: | |
195 | ||
196 | /* Flush the TLB (needed?) */ | |
197 | xorl %eax, %eax | |
198 | movl %eax, %cr3 | |
199 | ||
200 | /* Do the copies */ | |
201 | movl %ebx, %ecx | |
202 | jmp 1f | |
203 | ||
204 | 0: /* top, read another word from the indirection page */ | |
205 | movl (%ebx), %ecx | |
206 | addl $4, %ebx | |
207 | 1: | |
208 | testl $0x1, %ecx /* is it a destination page */ | |
209 | jz 2f | |
210 | movl %ecx, %edi | |
211 | andl $0xfffff000, %edi | |
212 | jmp 0b | |
213 | 2: | |
214 | testl $0x2, %ecx /* is it an indirection page */ | |
215 | jz 2f | |
216 | movl %ecx, %ebx | |
217 | andl $0xfffff000, %ebx | |
218 | jmp 0b | |
219 | 2: | |
220 | testl $0x4, %ecx /* is it the done indicator */ | |
221 | jz 2f | |
222 | jmp 3f | |
223 | 2: | |
224 | testl $0x8, %ecx /* is it the source indicator */ | |
225 | jz 0b /* Ignore it otherwise */ | |
226 | movl %ecx, %esi /* For every source page do a copy */ | |
227 | andl $0xfffff000, %esi | |
228 | ||
229 | movl $1024, %ecx | |
230 | rep ; movsl | |
231 | jmp 0b | |
232 | ||
233 | 3: | |
234 | ||
235 | /* To be certain of avoiding problems with self-modifying code | |
236 | * I need to execute a serializing instruction here. | |
237 | * So I flush the TLB, it's handy, and not processor dependent. | |
238 | */ | |
239 | xorl %eax, %eax | |
240 | movl %eax, %cr3 | |
241 | ||
242 | /* set all of the registers to known values */ | |
243 | /* leave %esp alone */ | |
244 | ||
245 | xorl %eax, %eax | |
246 | xorl %ebx, %ebx | |
247 | xorl %ecx, %ecx | |
248 | xorl %edx, %edx | |
249 | xorl %esi, %esi | |
250 | xorl %edi, %edi | |
251 | xorl %ebp, %ebp | |
252 | ret |