| /* |
| * relocate_kernel.S - put the kernel image in place to boot |
| * Copyright (C) 2002-2005 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> |
| #include <asm/processor-flags.h> |
| #include <asm/pgtable.h> |
| |
| /* |
| * Must be relocatable PIC code callable as a C function |
| */ |
| |
| #define PTR(x) (x << 3) |
| #define PAGE_ATTR (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY) |
| |
| .text |
| .align PAGE_SIZE |
| .code64 |
| .globl relocate_kernel |
| relocate_kernel: |
| /* %rdi indirection_page |
| * %rsi page_list |
| * %rdx start address |
| */ |
| |
| /* zero out flags, and disable interrupts */ |
| pushq $0 |
| popfq |
| |
| /* get physical address of control page now */ |
| /* this is impossible after page table switch */ |
| movq PTR(PA_CONTROL_PAGE)(%rsi), %r8 |
| |
| /* get physical address of page table now too */ |
| movq PTR(PA_TABLE_PAGE)(%rsi), %rcx |
| |
| /* Switch to the identity mapped page tables */ |
| movq %rcx, %cr3 |
| |
| /* setup a new stack at the end of the physical control page */ |
| lea PAGE_SIZE(%r8), %rsp |
| |
| /* jump to identity mapped page */ |
| addq $(identity_mapped - relocate_kernel), %r8 |
| pushq %r8 |
| ret |
| |
| identity_mapped: |
| /* store the start address on the stack */ |
| pushq %rdx |
| |
| /* Set cr0 to a known state: |
| * - Paging enabled |
| * - Alignment check disabled |
| * - Write protect disabled |
| * - No task switch |
| * - Don't do FP software emulation. |
| * - Proctected mode enabled |
| */ |
| movq %cr0, %rax |
| andq $~(X86_CR0_AM | X86_CR0_WP | X86_CR0_TS | X86_CR0_EM), %rax |
| orl $(X86_CR0_PG | X86_CR0_PE), %eax |
| movq %rax, %cr0 |
| |
| /* Set cr4 to a known state: |
| * - physical address extension enabled |
| */ |
| movq $X86_CR4_PAE, %rax |
| movq %rax, %cr4 |
| |
| jmp 1f |
| 1: |
| |
| /* Flush the TLB (needed?) */ |
| movq %rcx, %cr3 |
| |
| /* Do the copies */ |
| movq %rdi, %rcx /* Put the page_list in %rcx */ |
| xorq %rdi, %rdi |
| xorq %rsi, %rsi |
| jmp 1f |
| |
| 0: /* top, read another word for the indirection page */ |
| |
| movq (%rbx), %rcx |
| addq $8, %rbx |
| 1: |
| testq $0x1, %rcx /* is it a destination page? */ |
| jz 2f |
| movq %rcx, %rdi |
| andq $0xfffffffffffff000, %rdi |
| jmp 0b |
| 2: |
| testq $0x2, %rcx /* is it an indirection page? */ |
| jz 2f |
| movq %rcx, %rbx |
| andq $0xfffffffffffff000, %rbx |
| jmp 0b |
| 2: |
| testq $0x4, %rcx /* is it the done indicator? */ |
| jz 2f |
| jmp 3f |
| 2: |
| testq $0x8, %rcx /* is it the source indicator? */ |
| jz 0b /* Ignore it otherwise */ |
| movq %rcx, %rsi /* For ever source page do a copy */ |
| andq $0xfffffffffffff000, %rsi |
| |
| movq $512, %rcx |
| rep ; movsq |
| 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 by reloading %cr3 here, it's handy, |
| * and not processor dependent. |
| */ |
| movq %cr3, %rax |
| movq %rax, %cr3 |
| |
| /* set all of the registers to known values */ |
| /* leave %rsp alone */ |
| |
| xorq %rax, %rax |
| xorq %rbx, %rbx |
| xorq %rcx, %rcx |
| xorq %rdx, %rdx |
| xorq %rsi, %rsi |
| xorq %rdi, %rdi |
| xorq %rbp, %rbp |
| xorq %r8, %r8 |
| xorq %r9, %r9 |
| xorq %r10, %r9 |
| xorq %r11, %r11 |
| xorq %r12, %r12 |
| xorq %r13, %r13 |
| xorq %r14, %r14 |
| xorq %r15, %r15 |
| |
| ret |
