diff options
Diffstat (limited to 'grub-core/lib/x86_64/relocator_asm.S')
| -rw-r--r-- | grub-core/lib/x86_64/relocator_asm.S | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/grub-core/lib/x86_64/relocator_asm.S b/grub-core/lib/x86_64/relocator_asm.S new file mode 100644 index 0000000..2ab6d8c --- /dev/null +++ b/grub-core/lib/x86_64/relocator_asm.S @@ -0,0 +1,85 @@ +/* + * GRUB -- GRand Unified Bootloader + * Copyright (C) 2009 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/symbol.h> +#include <grub/i386/memory.h> + + .p2align 2 + +VARIABLE(grub_relocator_backward_start) + /* mov imm32, %rax */ + .byte 0x48 + .byte 0xb8 +VARIABLE(grub_relocator_backward_dest) + .long 0, 0 + movq %rax, %rdi + + /* mov imm64, %rax */ + .byte 0x48 + .byte 0xb8 +VARIABLE(grub_relocator_backward_src) + .long 0, 0 + movq %rax, %rsi + + /* mov imm64, %rcx */ + .byte 0x48 + .byte 0xb9 +VARIABLE(grub_relocator_backward_chunk_size) + .long 0, 0 + + add %rcx, %rsi + add %rcx, %rdi + + /* Backward movsb is implicitly off-by-one. compensate that. */ + sub $1, %rsi + sub $1, %rdi + + /* Backward copy. */ + std + + rep + movsb +VARIABLE(grub_relocator_backward_end) + + +VARIABLE(grub_relocator_forward_start) + /* mov imm64, %rax */ + .byte 0x48 + .byte 0xb8 +VARIABLE(grub_relocator_forward_dest) + .long 0, 0 + movq %rax, %rdi + + /* mov imm64, %rax */ + .byte 0x48 + .byte 0xb8 +VARIABLE(grub_relocator_forward_src) + .long 0, 0 + movq %rax, %rsi + + /* mov imm64, %rcx */ + .byte 0x48 + .byte 0xb9 +VARIABLE(grub_relocator_forward_chunk_size) + .long 0, 0 + + /* Forward copy. */ + cld + rep + movsb +VARIABLE(grub_relocator_forward_end) |