diff options
Diffstat (limited to 'arch/x86/kernel/relocate_kernel_64.S')
| -rw-r--r-- | arch/x86/kernel/relocate_kernel_64.S | 24 |
1 files changed, 16 insertions, 8 deletions
diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S index d32cfb27a479..cfc0d24003dc 100644 --- a/arch/x86/kernel/relocate_kernel_64.S +++ b/arch/x86/kernel/relocate_kernel_64.S | |||
| @@ -24,7 +24,8 @@ | |||
| 24 | .code64 | 24 | .code64 |
| 25 | .globl relocate_kernel | 25 | .globl relocate_kernel |
| 26 | relocate_kernel: | 26 | relocate_kernel: |
| 27 | /* %rdi indirection_page | 27 | /* |
| 28 | * %rdi indirection_page | ||
| 28 | * %rsi page_list | 29 | * %rsi page_list |
| 29 | * %rdx start address | 30 | * %rdx start address |
| 30 | */ | 31 | */ |
| @@ -33,8 +34,10 @@ relocate_kernel: | |||
| 33 | pushq $0 | 34 | pushq $0 |
| 34 | popfq | 35 | popfq |
| 35 | 36 | ||
| 36 | /* get physical address of control page now */ | 37 | /* |
| 37 | /* this is impossible after page table switch */ | 38 | * get physical address of control page now |
| 39 | * this is impossible after page table switch | ||
| 40 | */ | ||
| 38 | movq PTR(PA_CONTROL_PAGE)(%rsi), %r8 | 41 | movq PTR(PA_CONTROL_PAGE)(%rsi), %r8 |
| 39 | 42 | ||
| 40 | /* get physical address of page table now too */ | 43 | /* get physical address of page table now too */ |
| @@ -55,7 +58,8 @@ identity_mapped: | |||
| 55 | /* store the start address on the stack */ | 58 | /* store the start address on the stack */ |
| 56 | pushq %rdx | 59 | pushq %rdx |
| 57 | 60 | ||
| 58 | /* Set cr0 to a known state: | 61 | /* |
| 62 | * Set cr0 to a known state: | ||
| 59 | * - Paging enabled | 63 | * - Paging enabled |
| 60 | * - Alignment check disabled | 64 | * - Alignment check disabled |
| 61 | * - Write protect disabled | 65 | * - Write protect disabled |
| @@ -68,7 +72,8 @@ identity_mapped: | |||
| 68 | orl $(X86_CR0_PG | X86_CR0_PE), %eax | 72 | orl $(X86_CR0_PG | X86_CR0_PE), %eax |
| 69 | movq %rax, %cr0 | 73 | movq %rax, %cr0 |
| 70 | 74 | ||
| 71 | /* Set cr4 to a known state: | 75 | /* |
| 76 | * Set cr4 to a known state: | ||
| 72 | * - physical address extension enabled | 77 | * - physical address extension enabled |
| 73 | */ | 78 | */ |
| 74 | movq $X86_CR4_PAE, %rax | 79 | movq $X86_CR4_PAE, %rax |
| @@ -117,7 +122,8 @@ identity_mapped: | |||
| 117 | jmp 0b | 122 | jmp 0b |
| 118 | 3: | 123 | 3: |
| 119 | 124 | ||
| 120 | /* To be certain of avoiding problems with self-modifying code | 125 | /* |
| 126 | * To be certain of avoiding problems with self-modifying code | ||
| 121 | * I need to execute a serializing instruction here. | 127 | * I need to execute a serializing instruction here. |
| 122 | * So I flush the TLB by reloading %cr3 here, it's handy, | 128 | * So I flush the TLB by reloading %cr3 here, it's handy, |
| 123 | * and not processor dependent. | 129 | * and not processor dependent. |
| @@ -125,8 +131,10 @@ identity_mapped: | |||
| 125 | movq %cr3, %rax | 131 | movq %cr3, %rax |
| 126 | movq %rax, %cr3 | 132 | movq %rax, %cr3 |
| 127 | 133 | ||
| 128 | /* set all of the registers to known values */ | 134 | /* |
| 129 | /* leave %rsp alone */ | 135 | * set all of the registers to known values |
| 136 | * leave %rsp alone | ||
| 137 | */ | ||
| 130 | 138 | ||
| 131 | xorq %rax, %rax | 139 | xorq %rax, %rax |
| 132 | xorq %rbx, %rbx | 140 | xorq %rbx, %rbx |