diff options
Diffstat (limited to 'arch/x86/kernel/relocate_kernel_32.S')
| -rw-r--r-- | arch/x86/kernel/relocate_kernel_32.S | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/arch/x86/kernel/relocate_kernel_32.S b/arch/x86/kernel/relocate_kernel_32.S new file mode 100644 index 000000000000..f151d6fae462 --- /dev/null +++ b/arch/x86/kernel/relocate_kernel_32.S @@ -0,0 +1,252 @@ +/* + * 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.h> +#include <asm/kexec.h> + +/* + * Must be relocatable PIC code callable as a C function + */ + +#define PTR(x) (x << 2) +#define PAGE_ALIGNED (1 << PAGE_SHIFT) +#define PAGE_ATTR 0x63 /* _PAGE_PRESENT|_PAGE_RW|_PAGE_ACCESSED|_PAGE_DIRTY */ +#define PAE_PGD_ATTR 0x01 /* _PAGE_PRESENT */ + + .text + .align PAGE_ALIGNED + .globl relocate_kernel +relocate_kernel: + movl 8(%esp), %ebp /* list of pages */ + +#ifdef CONFIG_X86_PAE + /* map the control page at its virtual address */ + + movl PTR(VA_PGD)(%ebp), %edi + movl PTR(VA_CONTROL_PAGE)(%ebp), %eax + andl $0xc0000000, %eax + shrl $27, %eax + addl %edi, %eax + + movl PTR(PA_PMD_0)(%ebp), %edx + orl $PAE_PGD_ATTR, %edx + movl %edx, (%eax) + + movl PTR(VA_PMD_0)(%ebp), %edi + movl PTR(VA_CONTROL_PAGE)(%ebp), %eax + andl $0x3fe00000, %eax + shrl $18, %eax + addl %edi, %eax + + movl PTR(PA_PTE_0)(%ebp), %edx + orl $PAGE_ATTR, %edx + movl %edx, (%eax) + + movl PTR(VA_PTE_0)(%ebp), %edi + movl PTR(VA_CONTROL_PAGE)(%ebp), %eax + andl $0x001ff000, %eax + shrl $9, %eax + addl %edi, %eax + + movl PTR(PA_CONTROL_PAGE)(%ebp), %edx + orl $PAGE_ATTR, %edx + movl %edx, (%eax) + + /* identity map the control page at its physical address */ + + movl PTR(VA_PGD)(%ebp), %edi + movl PTR(PA_CONTROL_PAGE)(%ebp), %eax + andl $0xc0000000, %eax + shrl $27, %eax + addl %edi, %eax + + movl PTR(PA_PMD_1)(%ebp), %edx + orl $PAE_PGD_ATTR, %edx + movl %edx, (%eax) + + movl PTR(VA_PMD_1)(%ebp), %edi + movl PTR(PA_CONTROL_PAGE)(%ebp), %eax + andl $0x3fe00000, %eax + shrl $18, %eax + addl %edi, %eax + + movl PTR(PA_PTE_1)(%ebp), %edx + orl $PAGE_ATTR, %edx + movl %edx, (%eax) + + movl PTR(VA_PTE_1)(%ebp), %edi + movl PTR(PA_CONTROL_PAGE)(%ebp), %eax + andl $0x001ff000, %eax + shrl $9, %eax + addl %edi, %eax + + movl PTR(PA_CONTROL_PAGE)(%ebp), %edx + orl $PAGE_ATTR, %edx + movl %edx, (%eax) +#else + /* map the control page at its virtual address */ + + movl PTR(VA_PGD)(%ebp), %edi + movl PTR(VA_CONTROL_PAGE)(%ebp), %eax + andl $0xffc00000, %eax + shrl $20, %eax + addl %edi, %eax + + movl PTR(PA_PTE_0)(%ebp), %edx + orl $PAGE_ATTR, %edx + movl %edx, (%eax) + + movl PTR(VA_PTE_0)(%ebp), %edi + movl PTR(VA_CONTROL_PAGE)(%ebp), %eax + andl $0x003ff000, %eax + shrl $10, %eax + addl %edi, %eax + + movl PTR(PA_CONTROL_PAGE)(%ebp), %edx + orl $PAGE_ATTR, %edx + movl %edx, (%eax) + + /* identity map the control page at its physical address */ + + movl PTR(VA_PGD)(%ebp), %edi + movl PTR(PA_CONTROL_PAGE)(%ebp), %eax + andl $0xffc00000, %eax + shrl $20, %eax + addl %edi, %eax + + movl PTR(PA_PTE_1)(%ebp), %edx + orl $PAGE_ATTR, %edx + movl %edx, (%eax) + + movl PTR(VA_PTE_1)(%ebp), %edi + movl PTR(PA_CONTROL_PAGE)(%ebp), %eax + andl $0x003ff000, %eax + shrl $10, %eax + addl %edi, %eax + + movl PTR(PA_CONTROL_PAGE)(%ebp), %edx + orl $PAGE_ATTR, %edx + movl %edx, (%eax) +#endif + +relocate_new_kernel: + /* read the arguments and say goodbye to the stack */ + movl 4(%esp), %ebx /* page_list */ + movl 8(%esp), %ebp /* list of pages */ + movl 12(%esp), %edx /* start address */ + movl 16(%esp), %ecx /* cpu_has_pae */ + + /* zero out flags, and disable interrupts */ + pushl $0 + popfl + + /* 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 4096(%edi), %esp + + /* jump to identity mapped page */ + movl %edi, %eax + addl $(identity_mapped - relocate_kernel), %eax + pushl %eax + ret + +identity_mapped: + /* store the start address on the stack */ + pushl %edx + + /* Set cr0 to a known state: + * 31 0 == Paging disabled + * 18 0 == Alignment check disabled + * 16 0 == Write protect disabled + * 3 0 == No task switch + * 2 0 == Don't do FP software emulation. + * 0 1 == Proctected mode enabled + */ + movl %cr0, %eax + andl $~((1<<31)|(1<<18)|(1<<16)|(1<<3)|(1<<2)), %eax + orl $(1<<0), %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. + */ + movl %cr4, %eax + andl $0, %eax + movl %eax, %cr4 + + jmp 1f +1: + + /* Flush the TLB (needed?) */ + xorl %eax, %eax + movl %eax, %cr3 + + /* Do the copies */ + movl %ebx, %ecx + jmp 1f + +0: /* top, read another word from the indirection page */ + movl (%ebx), %ecx + addl $4, %ebx +1: + testl $0x1, %ecx /* is it a destination page */ + jz 2f + movl %ecx, %edi + andl $0xfffff000, %edi + jmp 0b +2: + testl $0x2, %ecx /* is it an indirection page */ + jz 2f + movl %ecx, %ebx + andl $0xfffff000, %ebx + jmp 0b +2: + testl $0x4, %ecx /* is it the done indicator */ + jz 2f + jmp 3f +2: + testl $0x8, %ecx /* is it the source indicator */ + jz 0b /* Ignore it otherwise */ + movl %ecx, %esi /* For every source page do a copy */ + andl $0xfffff000, %esi + + movl $1024, %ecx + rep ; movsl + jmp 0b + +3: + + /* 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 */ + + xorl %eax, %eax + xorl %ebx, %ebx + xorl %ecx, %ecx + xorl %edx, %edx + xorl %esi, %esi + xorl %edi, %edi + xorl %ebp, %ebp + ret |
