grub/grub-core/lib/i386/relocator64.S
Daniel Kiper 9862b24121 i386/relocator: Add grub_relocator64_efi relocator
Add grub_relocator64_efi relocator. It will be used on EFI 64-bit platforms
when multiboot2 compatible image requests MULTIBOOT_TAG_TYPE_EFI_BS. Relocator
will set lower parts of %rax and %rbx accordingly to multiboot2 specification.
On the other hand processor mode, just before jumping into loaded image, will
be set accordingly to Unified Extensible Firmware Interface Specification,
Version 2.4 Errata B, section 2.3.4, x64 Platforms, boot services. This way
loaded image will be able to use EFI boot services without any issues.

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Vladimir Serbinenko <phcoder@gmail.com>
2016-10-27 15:53:43 +02:00

176 lines
4.1 KiB
ArmAsm

/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2009,2010 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/>.
*/
#define CODE32_SEGMENT 0x18
#define CODE_SEGMENT 0x08
/* The data segment of the protected mode. */
#define DATA_SEGMENT 0x10
#include "relocator_common.S"
.p2align 4 /* force 16-byte alignment */
VARIABLE(grub_relocator64_start)
PREAMBLE
#ifndef __x86_64__
DISABLE_PAGING
/* Turn on PAE. */
movl %cr4, %eax
orl $(GRUB_MEMORY_CPU_CR4_PAE_ON | GRUB_MEMORY_CPU_CR4_PSE_ON), %eax
movl %eax, %cr4
/* mov imm32, %eax */
.byte 0xb8
VARIABLE(grub_relocator64_cr3)
.long 0
movl %eax, %cr3
/* Turn on amd64. */
movl $GRUB_MEMORY_CPU_AMD64_MSR, %ecx
rdmsr
orl $GRUB_MEMORY_CPU_AMD64_MSR_ON, %eax
wrmsr
/* Enable paging. */
movl %cr0, %eax
orl $GRUB_MEMORY_CPU_CR0_PAGING_ON, %eax
movl %eax, %cr0
RELOAD_GDT
#else
/* mov imm64, %rax */
.byte 0x48
.byte 0xb8
VARIABLE(grub_relocator64_cr3)
.quad 0
movq %rax, %cr3
#endif
.code64
/* mov imm64, %rax */
.byte 0x48
.byte 0xb8
VARIABLE(grub_relocator64_rsp)
.quad 0
movq %rax, %rsp
/*
* Here is grub_relocator64_efi_start() entry point.
* Following code is shared between grub_relocator64_efi_start()
* and grub_relocator64_start().
*
* Think twice before changing anything below!!!
*/
VARIABLE(grub_relocator64_efi_start)
/* mov imm64, %rax */
.byte 0x48
.byte 0xb8
VARIABLE(grub_relocator64_rsi)
.quad 0
movq %rax, %rsi
/* mov imm64, %rax */
.byte 0x48
.byte 0xb8
VARIABLE(grub_relocator64_rax)
.quad 0
/* mov imm64, %rbx */
.byte 0x48
.byte 0xbb
VARIABLE(grub_relocator64_rbx)
.quad 0
/* mov imm64, %rcx */
.byte 0x48
.byte 0xb9
VARIABLE(grub_relocator64_rcx)
.quad 0
/* mov imm64, %rdx */
.byte 0x48
.byte 0xba
VARIABLE(grub_relocator64_rdx)
.quad 0
/* Cleared direction flag is of no problem with any current
payload and makes this implementation easier. */
cld
#ifdef __APPLE__
.byte 0xff, 0x25
.quad 0
#else
jmp *LOCAL(jump_addr) (%rip)
#endif
LOCAL(jump_addr):
VARIABLE(grub_relocator64_rip)
.quad 0
/* Here grub_relocator64_efi_start() ends. Ufff... */
VARIABLE(grub_relocator64_efi_end)
#ifndef __x86_64__
.p2align 4
LOCAL(gdt):
/* NULL. */
.byte 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
/* 64-bit segment. */
.word 0xffff /* Limit xffff. */
.word 0x0000 /* Base xxxx0000. */
.byte 0x00 /* Base xx00xxxx. */
.byte (0x8 /* Type 8. */ | (1 << 4) /* Code. */ \
| (0 << 5) /* Ring 0. */ | (1 << 7) /* Present. */)
.byte (0xf /* Limit fxxxx. */ | (0 << 4) /* AVL flag. */ \
| (1 << 5) /* 64-bit. */ | (0 << 6) \
| (1 << 7) /* 4K granular. */)
.byte 0x00 /* Base 00xxxxxx. */
/* Data segment*/
.word 0xffff /* Limit xffff. */
.word 0x0000 /* Base xxxx0000. */
.byte 0x00 /* Base xx00xxxx. */
.byte (0x0 /* Type 0. */ | (0 << 4) /* Data. */ \
| (0 << 5) /* Ring 0. */ | (1 << 7) /* Present. */)
.byte (0xf /* Limit fxxxx. */ | (0 << 4) /* AVL flag. */ \
| (0 << 5) /* Data. */ | (0 << 6) \
| (1 << 7) /* 4K granular. */)
.byte 0x00 /* Base 00xxxxxx. */
/* Compatibility segment. */
.word 0xffff /* Limit xffff. */
.word 0x0000 /* Base xxxx0000. */
.byte 0x00 /* Base xx00xxxx. */
.byte (0x8 /* Type 8. */ | (1 << 4) /* Code. */ \
| (0 << 5) /* Ring 0. */ | (1 << 7) /* Present. */)
.byte (0xf /* Limit fxxxx. */ | (0 << 4) /* AVL flag. */ \
| (0 << 5) /* 32-bit. */ | (1 << 6) /* 32-bit. */ \
| (1 << 7) /* 4K granular. */)
.byte 0x00 /* Base 00xxxxxx. */
LOCAL(gdt_end):
#endif
VARIABLE(grub_relocator64_end)