diff options
Diffstat (limited to 'grub-core/lib/i386/xen/relocator.S')
| -rw-r--r-- | grub-core/lib/i386/xen/relocator.S | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/grub-core/lib/i386/xen/relocator.S b/grub-core/lib/i386/xen/relocator.S new file mode 100644 index 0000000..96e51b5 --- /dev/null +++ b/grub-core/lib/i386/xen/relocator.S @@ -0,0 +1,165 @@ +/* + * 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) |