--- /dev/null
+/*
+ * 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
projects / karo-tx-linux.git / blobdiff