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/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2013 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#include <grub/i386/memory.h>
#include <grub/i386/types.h>
#include <grub/symbol.h>
#include <grub/xen.h>
.p2align 4 /* force 16-byte alignment */
VARIABLE(grub_relocator_xen_remap_start)
LOCAL(base):
/* Remap the remapper to it's new address. */
/* mov imm32, %ebx - %ebx: new virtual address of remapper */
.byte 0xbb
VARIABLE(grub_relocator_xen_remapper_virt)
.long 0
/* mov imm32, %ecx - %ecx: low part of page table entry */
.byte 0xb9
VARIABLE(grub_relocator_xen_remapper_map)
.long 0
/* mov imm32, %edx - %edx: high part of page table entry */
.byte 0xba
VARIABLE(grub_relocator_xen_remapper_map_high)
.long 0
movl %ebx, %ebp /* %ebx is clobbered by hypercall */
movl $UVMF_INVLPG, %esi /* esi: flags (inv. single entry) */
movl $__HYPERVISOR_update_va_mapping, %eax
int $0x82
movl %ebp, %ebx
addl $(LOCAL(cont) - LOCAL(base)), %ebx
jmp *%ebx /* Continue with new virtual address */
LOCAL(cont):
/* Modify mappings of new page tables to be read-only. */
/* mov imm32, %eax */
.byte 0xb8
VARIABLE(grub_relocator_xen_paging_areas_addr)
.long 0
movl %eax, %ebx
1:
movl 0(%ebx), %ebp /* Get start pfn of the current area */
movl GRUB_TARGET_SIZEOF_LONG(%ebx), %ecx /* Get # of pg tables */
testl %ecx, %ecx /* 0 -> last area reached */
jz 3f
addl $(2 * GRUB_TARGET_SIZEOF_LONG), %ebx
movl %ebx, %esp /* Save current area pointer */
2:
movl %ecx, %edi
/* mov imm32, %eax */
.byte 0xb8
VARIABLE(grub_relocator_xen_mfn_list)
.long 0
movl 0(%eax, %ebp, 4), %ecx /* mfn */
movl %ebp, %ebx
shll $PAGE_SHIFT, %ebx /* virtual address (1:1 mapping) */
movl %ecx, %edx
shll $PAGE_SHIFT, %ecx /* prepare pte low part */
shrl $(32 - PAGE_SHIFT), %edx /* pte high part */
orl $(GRUB_PAGE_PRESENT | GRUB_PAGE_USER), %ecx /* pte low */
movl $UVMF_INVLPG, %esi
movl $__HYPERVISOR_update_va_mapping, %eax
int $0x82 /* parameters: eax, ebx, ecx, edx, esi */
incl %ebp /* next pfn */
movl %edi, %ecx
loop 2b
mov %esp, %ebx /* restore area poniter */
jmp 1b
3:
/* Switch page tables: pin new L3 pt, load cr3, unpin old L3. */
/* mov imm32, %ebx */
.byte 0xbb
VARIABLE(grub_relocator_xen_mmu_op_addr)
.long 0
movl $3, %ecx /* 3 mmu ops */
movl $0, %edx /* pdone (not used) */
movl $DOMID_SELF, %esi
movl $__HYPERVISOR_mmuext_op, %eax
int $0x82
/* Continue in virtual kernel mapping. */
/* mov imm32, %eax */
.byte 0xb8
VARIABLE(grub_relocator_xen_remap_continue)
.long 0
jmp *%eax
VARIABLE(grub_relocator_xen_paging_areas)
.long 0, 0, 0, 0, 0, 0, 0, 0
VARIABLE(grub_relocator_xen_mmu_op)
.space 256
VARIABLE(grub_relocator_xen_remap_end)
VARIABLE(grub_relocator_xen_start)
/* Unmap old remapper area. */
/* mov imm32, %eax */
.byte 0xb8
VARIABLE(grub_relocator_xen_remapper_virt2)
.long 0
movl %eax, %ebx
xorl %ecx, %ecx /* Invalid pte */
xorl %edx, %edx
movl $UVMF_INVLPG, %esi
movl $__HYPERVISOR_update_va_mapping, %eax
int $0x82
/* Prepare registers for starting kernel. */
/* mov imm32, %eax */
.byte 0xb8
VARIABLE(grub_relocator_xen_stack)
.long 0
movl %eax, %esp
/* mov imm32, %eax */
.byte 0xb8
VARIABLE(grub_relocator_xen_start_info)
.long 0
movl %eax, %esi
cld
/* mov imm32, %eax */
.byte 0xb8
VARIABLE(grub_relocator_xen_entry_point)
.long 0
/* Now start the new kernel. */
jmp *%eax
VARIABLE(grub_relocator_xen_end)
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