You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
277 lines
5.6 KiB
277 lines
5.6 KiB
/*
|
|
* relocate_kernel.S - put the kernel image in place to boot
|
|
* Copyright (C) 2002-2004 Eric Biederman <ebiederm@xmission.com>
|
|
*
|
|
* This source code is licensed under the GNU General Public License,
|
|
* Version 2. See the file COPYING for more details.
|
|
*/
|
|
|
|
#include <linux/linkage.h>
|
|
#include <asm/page_types.h>
|
|
#include <asm/kexec.h>
|
|
#include <asm/processor-flags.h>
|
|
|
|
/*
|
|
* Must be relocatable PIC code callable as a C function
|
|
*/
|
|
|
|
#define PTR(x) (x << 2)
|
|
|
|
/*
|
|
* control_page + KEXEC_CONTROL_CODE_MAX_SIZE
|
|
* ~ control_page + PAGE_SIZE are used as data storage and stack for
|
|
* jumping back
|
|
*/
|
|
#define DATA(offset) (KEXEC_CONTROL_CODE_MAX_SIZE+(offset))
|
|
|
|
/* Minimal CPU state */
|
|
#define ESP DATA(0x0)
|
|
#define CR0 DATA(0x4)
|
|
#define CR3 DATA(0x8)
|
|
#define CR4 DATA(0xc)
|
|
|
|
/* other data */
|
|
#define CP_VA_CONTROL_PAGE DATA(0x10)
|
|
#define CP_PA_PGD DATA(0x14)
|
|
#define CP_PA_SWAP_PAGE DATA(0x18)
|
|
#define CP_PA_BACKUP_PAGES_MAP DATA(0x1c)
|
|
|
|
.text
|
|
.globl relocate_kernel
|
|
relocate_kernel:
|
|
/* Save the CPU context, used for jumping back */
|
|
|
|
pushl %ebx
|
|
pushl %esi
|
|
pushl %edi
|
|
pushl %ebp
|
|
pushf
|
|
|
|
movl 20+8(%esp), %ebp /* list of pages */
|
|
movl PTR(VA_CONTROL_PAGE)(%ebp), %edi
|
|
movl %esp, ESP(%edi)
|
|
movl %cr0, %eax
|
|
movl %eax, CR0(%edi)
|
|
movl %cr3, %eax
|
|
movl %eax, CR3(%edi)
|
|
movl %cr4, %eax
|
|
movl %eax, CR4(%edi)
|
|
|
|
/* read the arguments and say goodbye to the stack */
|
|
movl 20+4(%esp), %ebx /* page_list */
|
|
movl 20+8(%esp), %ebp /* list of pages */
|
|
movl 20+12(%esp), %edx /* start address */
|
|
movl 20+16(%esp), %ecx /* cpu_has_pae */
|
|
movl 20+20(%esp), %esi /* preserve_context */
|
|
|
|
/* zero out flags, and disable interrupts */
|
|
pushl $0
|
|
popfl
|
|
|
|
/* save some information for jumping back */
|
|
movl PTR(VA_CONTROL_PAGE)(%ebp), %edi
|
|
movl %edi, CP_VA_CONTROL_PAGE(%edi)
|
|
movl PTR(PA_PGD)(%ebp), %eax
|
|
movl %eax, CP_PA_PGD(%edi)
|
|
movl PTR(PA_SWAP_PAGE)(%ebp), %eax
|
|
movl %eax, CP_PA_SWAP_PAGE(%edi)
|
|
movl %ebx, CP_PA_BACKUP_PAGES_MAP(%edi)
|
|
|
|
/*
|
|
* get physical address of control page now
|
|
* this is impossible after page table switch
|
|
*/
|
|
movl PTR(PA_CONTROL_PAGE)(%ebp), %edi
|
|
|
|
/* switch to new set of page tables */
|
|
movl PTR(PA_PGD)(%ebp), %eax
|
|
movl %eax, %cr3
|
|
|
|
/* setup a new stack at the end of the physical control page */
|
|
lea PAGE_SIZE(%edi), %esp
|
|
|
|
/* jump to identity mapped page */
|
|
movl %edi, %eax
|
|
addl $(identity_mapped - relocate_kernel), %eax
|
|
pushl %eax
|
|
ret
|
|
|
|
identity_mapped:
|
|
/* set return address to 0 if not preserving context */
|
|
pushl $0
|
|
/* store the start address on the stack */
|
|
pushl %edx
|
|
|
|
/*
|
|
* Set cr0 to a known state:
|
|
* - Paging disabled
|
|
* - Alignment check disabled
|
|
* - Write protect disabled
|
|
* - No task switch
|
|
* - Don't do FP software emulation.
|
|
* - Proctected mode enabled
|
|
*/
|
|
movl %cr0, %eax
|
|
andl $~(X86_CR0_PG | X86_CR0_AM | X86_CR0_WP | X86_CR0_TS | X86_CR0_EM), %eax
|
|
orl $(X86_CR0_PE), %eax
|
|
movl %eax, %cr0
|
|
|
|
/* clear cr4 if applicable */
|
|
testl %ecx, %ecx
|
|
jz 1f
|
|
/*
|
|
* Set cr4 to a known state:
|
|
* Setting everything to zero seems safe.
|
|
*/
|
|
xorl %eax, %eax
|
|
movl %eax, %cr4
|
|
|
|
jmp 1f
|
|
1:
|
|
|
|
/* Flush the TLB (needed?) */
|
|
xorl %eax, %eax
|
|
movl %eax, %cr3
|
|
|
|
movl CP_PA_SWAP_PAGE(%edi), %eax
|
|
pushl %eax
|
|
pushl %ebx
|
|
call swap_pages
|
|
addl $8, %esp
|
|
|
|
/*
|
|
* To be certain of avoiding problems with self-modifying code
|
|
* I need to execute a serializing instruction here.
|
|
* So I flush the TLB, it's handy, and not processor dependent.
|
|
*/
|
|
xorl %eax, %eax
|
|
movl %eax, %cr3
|
|
|
|
/*
|
|
* set all of the registers to known values
|
|
* leave %esp alone
|
|
*/
|
|
|
|
testl %esi, %esi
|
|
jnz 1f
|
|
xorl %edi, %edi
|
|
xorl %eax, %eax
|
|
xorl %ebx, %ebx
|
|
xorl %ecx, %ecx
|
|
xorl %edx, %edx
|
|
xorl %esi, %esi
|
|
xorl %ebp, %ebp
|
|
ret
|
|
1:
|
|
popl %edx
|
|
movl CP_PA_SWAP_PAGE(%edi), %esp
|
|
addl $PAGE_SIZE, %esp
|
|
2:
|
|
call *%edx
|
|
|
|
/* get the re-entry point of the peer system */
|
|
movl 0(%esp), %ebp
|
|
call 1f
|
|
1:
|
|
popl %ebx
|
|
subl $(1b - relocate_kernel), %ebx
|
|
movl CP_VA_CONTROL_PAGE(%ebx), %edi
|
|
lea PAGE_SIZE(%ebx), %esp
|
|
movl CP_PA_SWAP_PAGE(%ebx), %eax
|
|
movl CP_PA_BACKUP_PAGES_MAP(%ebx), %edx
|
|
pushl %eax
|
|
pushl %edx
|
|
call swap_pages
|
|
addl $8, %esp
|
|
movl CP_PA_PGD(%ebx), %eax
|
|
movl %eax, %cr3
|
|
movl %cr0, %eax
|
|
orl $X86_CR0_PG, %eax
|
|
movl %eax, %cr0
|
|
lea PAGE_SIZE(%edi), %esp
|
|
movl %edi, %eax
|
|
addl $(virtual_mapped - relocate_kernel), %eax
|
|
pushl %eax
|
|
ret
|
|
|
|
virtual_mapped:
|
|
movl CR4(%edi), %eax
|
|
movl %eax, %cr4
|
|
movl CR3(%edi), %eax
|
|
movl %eax, %cr3
|
|
movl CR0(%edi), %eax
|
|
movl %eax, %cr0
|
|
movl ESP(%edi), %esp
|
|
movl %ebp, %eax
|
|
|
|
popf
|
|
popl %ebp
|
|
popl %edi
|
|
popl %esi
|
|
popl %ebx
|
|
ret
|
|
|
|
/* Do the copies */
|
|
swap_pages:
|
|
movl 8(%esp), %edx
|
|
movl 4(%esp), %ecx
|
|
pushl %ebp
|
|
pushl %ebx
|
|
pushl %edi
|
|
pushl %esi
|
|
movl %ecx, %ebx
|
|
jmp 1f
|
|
|
|
0: /* top, read another word from the indirection page */
|
|
movl (%ebx), %ecx
|
|
addl $4, %ebx
|
|
1:
|
|
testb $0x1, %cl /* is it a destination page */
|
|
jz 2f
|
|
movl %ecx, %edi
|
|
andl $0xfffff000, %edi
|
|
jmp 0b
|
|
2:
|
|
testb $0x2, %cl /* is it an indirection page */
|
|
jz 2f
|
|
movl %ecx, %ebx
|
|
andl $0xfffff000, %ebx
|
|
jmp 0b
|
|
2:
|
|
testb $0x4, %cl /* is it the done indicator */
|
|
jz 2f
|
|
jmp 3f
|
|
2:
|
|
testb $0x8, %cl /* is it the source indicator */
|
|
jz 0b /* Ignore it otherwise */
|
|
movl %ecx, %esi /* For every source page do a copy */
|
|
andl $0xfffff000, %esi
|
|
|
|
movl %edi, %eax
|
|
movl %esi, %ebp
|
|
|
|
movl %edx, %edi
|
|
movl $1024, %ecx
|
|
rep ; movsl
|
|
|
|
movl %ebp, %edi
|
|
movl %eax, %esi
|
|
movl $1024, %ecx
|
|
rep ; movsl
|
|
|
|
movl %eax, %edi
|
|
movl %edx, %esi
|
|
movl $1024, %ecx
|
|
rep ; movsl
|
|
|
|
lea PAGE_SIZE(%ebp), %esi
|
|
jmp 0b
|
|
3:
|
|
popl %esi
|
|
popl %edi
|
|
popl %ebx
|
|
popl %ebp
|
|
ret
|
|
|
|
.globl kexec_control_code_size
|
|
.set kexec_control_code_size, . - relocate_kernel
|
|
|