diff options
Diffstat (limited to 'arch/i386/kernel/relocate_kernel.S')
| -rw-r--r-- | arch/i386/kernel/relocate_kernel.S | 162 |
1 files changed, 147 insertions, 15 deletions
diff --git a/arch/i386/kernel/relocate_kernel.S b/arch/i386/kernel/relocate_kernel.S index d312616effa..f151d6fae46 100644 --- a/arch/i386/kernel/relocate_kernel.S +++ b/arch/i386/kernel/relocate_kernel.S @@ -7,16 +7,138 @@ */ #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 - /* - * Must be relocatable PIC code callable as a C function, that once - * it starts can not use the previous processes stack. - */ - .globl relocate_new_kernel relocate_new_kernel: /* read the arguments and say goodbye to the stack */ movl 4(%esp), %ebx /* page_list */ - movl 8(%esp), %ebp /* reboot_code_buffer */ + movl 8(%esp), %ebp /* list of pages */ movl 12(%esp), %edx /* start address */ movl 16(%esp), %ecx /* cpu_has_pae */ @@ -24,11 +146,26 @@ relocate_new_kernel: pushl $0 popfl - /* set a new stack at the bottom of our page... */ - lea 4096(%ebp), %esp + /* get physical address of control page now */ + /* this is impossible after page table switch */ + movl PTR(PA_CONTROL_PAGE)(%ebp), %edi - /* store the parameters back on the stack */ - pushl %edx /* store the start address */ + /* 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 @@ -113,8 +250,3 @@ relocate_new_kernel: xorl %edi, %edi xorl %ebp, %ebp ret -relocate_new_kernel_end: - - .globl relocate_new_kernel_size -relocate_new_kernel_size: - .long relocate_new_kernel_end - relocate_new_kernel |