2 * relocate_kernel.S - put the kernel image in place to boot
3 * Copyright (C) 2002-2004 Eric Biederman <ebiederm@xmission.com>
5 * This source code is licensed under the GNU General Public License,
6 * Version 2. See the file COPYING for more details.
9 #include <linux/linkage.h>
11 #include <asm/kexec.h>
14 * Must be relocatable PIC code callable as a C function
17 #define PTR(x) (x << 2)
18 #define PAGE_ATTR 0x63 /* _PAGE_PRESENT|_PAGE_RW|_PAGE_ACCESSED|_PAGE_DIRTY */
19 #define PAE_PGD_ATTR 0x01 /* _PAGE_PRESENT */
23 .globl relocate_kernel
25 movl 8(%esp), %ebp /* list of pages */
28 /* map the control page at its virtual address */
30 movl PTR(VA_PGD)(%ebp), %edi
31 movl PTR(VA_CONTROL_PAGE)(%ebp), %eax
32 andl $0xc0000000, %eax
36 movl PTR(PA_PMD_0)(%ebp), %edx
37 orl $PAE_PGD_ATTR, %edx
40 movl PTR(VA_PMD_0)(%ebp), %edi
41 movl PTR(VA_CONTROL_PAGE)(%ebp), %eax
42 andl $0x3fe00000, %eax
46 movl PTR(PA_PTE_0)(%ebp), %edx
50 movl PTR(VA_PTE_0)(%ebp), %edi
51 movl PTR(VA_CONTROL_PAGE)(%ebp), %eax
52 andl $0x001ff000, %eax
56 movl PTR(PA_CONTROL_PAGE)(%ebp), %edx
60 /* identity map the control page at its physical address */
62 movl PTR(VA_PGD)(%ebp), %edi
63 movl PTR(PA_CONTROL_PAGE)(%ebp), %eax
64 andl $0xc0000000, %eax
68 movl PTR(PA_PMD_1)(%ebp), %edx
69 orl $PAE_PGD_ATTR, %edx
72 movl PTR(VA_PMD_1)(%ebp), %edi
73 movl PTR(PA_CONTROL_PAGE)(%ebp), %eax
74 andl $0x3fe00000, %eax
78 movl PTR(PA_PTE_1)(%ebp), %edx
82 movl PTR(VA_PTE_1)(%ebp), %edi
83 movl PTR(PA_CONTROL_PAGE)(%ebp), %eax
84 andl $0x001ff000, %eax
88 movl PTR(PA_CONTROL_PAGE)(%ebp), %edx
92 /* map the control page at its virtual address */
94 movl PTR(VA_PGD)(%ebp), %edi
95 movl PTR(VA_CONTROL_PAGE)(%ebp), %eax
96 andl $0xffc00000, %eax
100 movl PTR(PA_PTE_0)(%ebp), %edx
104 movl PTR(VA_PTE_0)(%ebp), %edi
105 movl PTR(VA_CONTROL_PAGE)(%ebp), %eax
106 andl $0x003ff000, %eax
110 movl PTR(PA_CONTROL_PAGE)(%ebp), %edx
114 /* identity map the control page at its physical address */
116 movl PTR(VA_PGD)(%ebp), %edi
117 movl PTR(PA_CONTROL_PAGE)(%ebp), %eax
118 andl $0xffc00000, %eax
122 movl PTR(PA_PTE_1)(%ebp), %edx
126 movl PTR(VA_PTE_1)(%ebp), %edi
127 movl PTR(PA_CONTROL_PAGE)(%ebp), %eax
128 andl $0x003ff000, %eax
132 movl PTR(PA_CONTROL_PAGE)(%ebp), %edx
138 /* read the arguments and say goodbye to the stack */
139 movl 4(%esp), %ebx /* page_list */
140 movl 8(%esp), %ebp /* list of pages */
141 movl 12(%esp), %edx /* start address */
142 movl 16(%esp), %ecx /* cpu_has_pae */
144 /* zero out flags, and disable interrupts */
148 /* get physical address of control page now */
149 /* this is impossible after page table switch */
150 movl PTR(PA_CONTROL_PAGE)(%ebp), %edi
152 /* switch to new set of page tables */
153 movl PTR(PA_PGD)(%ebp), %eax
156 /* setup a new stack at the end of the physical control page */
159 /* jump to identity mapped page */
161 addl $(identity_mapped - relocate_kernel), %eax
166 /* store the start address on the stack */
169 /* Set cr0 to a known state:
170 * 31 0 == Paging disabled
171 * 18 0 == Alignment check disabled
172 * 16 0 == Write protect disabled
173 * 3 0 == No task switch
174 * 2 0 == Don't do FP software emulation.
175 * 0 1 == Proctected mode enabled
178 andl $~((1<<31)|(1<<18)|(1<<16)|(1<<3)|(1<<2)), %eax
182 /* clear cr4 if applicable */
185 /* Set cr4 to a known state:
186 * Setting everything to zero seems safe.
195 /* Flush the TLB (needed?) */
203 0: /* top, read another word from the indirection page */
207 testl $0x1, %ecx /* is it a destination page */
210 andl $0xfffff000, %edi
213 testl $0x2, %ecx /* is it an indirection page */
216 andl $0xfffff000, %ebx
219 testl $0x4, %ecx /* is it the done indicator */
223 testl $0x8, %ecx /* is it the source indicator */
224 jz 0b /* Ignore it otherwise */
225 movl %ecx, %esi /* For every source page do a copy */
226 andl $0xfffff000, %esi
234 /* To be certain of avoiding problems with self-modifying code
235 * I need to execute a serializing instruction here.
236 * So I flush the TLB, it's handy, and not processor dependent.
241 /* set all of the registers to known values */
242 /* leave %esp alone */