| /* |
| * 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> |
| |
| /* |
| * 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 12(%esp), %edx /* start address */ |
| movl 16(%esp), %ecx /* cpu_has_pae */ |
| |
| /* zero out flags, and disable interrupts */ |
| pushl $0 |
| popfl |
| |
| /* set a new stack at the bottom of our page... */ |
| lea 4096(%ebp), %esp |
| |
| /* store the parameters back on the stack */ |
| pushl %edx /* store the start address */ |
| |
| /* 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 |
| relocate_new_kernel_end: |
| |
| .globl relocate_new_kernel_size |
| relocate_new_kernel_size: |
| .long relocate_new_kernel_end - relocate_new_kernel |