diff options
Diffstat (limited to 'grub-core/kern/i386/xen/startup_pvh.S')
| -rw-r--r-- | grub-core/kern/i386/xen/startup_pvh.S | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/grub-core/kern/i386/xen/startup_pvh.S b/grub-core/kern/i386/xen/startup_pvh.S new file mode 100644 index 0000000..363c318 --- /dev/null +++ b/grub-core/kern/i386/xen/startup_pvh.S @@ -0,0 +1,81 @@ +/* startup.S - bootstrap GRUB itself */ +/* + * GRUB -- GRand Unified Bootloader + * Copyright (C) 2018 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 <config.h> +#include <grub/symbol.h> +#include <grub/machine/memory.h> + + .file "startup_pvh.S" + .text + .globl start, _start + .code32 + +start: +_start: + cld + lgdt gdtdesc + ljmp $GRUB_MEMORY_MACHINE_PROT_MODE_CSEG, $1f +1: + movl $GRUB_MEMORY_MACHINE_PROT_MODE_DSEG, %eax + mov %eax, %ds + mov %eax, %es + mov %eax, %fs + mov %eax, %gs + mov %eax, %ss + leal LOCAL(stack_end), %esp + + /* Save address of start info structure. */ + mov %ebx, pvh_start_info + call EXT_C(grub_main) + /* Doesn't return. */ + + .p2align 3 +gdt: + .word 0, 0 + .byte 0, 0, 0, 0 + + /* -- code segment -- + * base = 0x00000000, limit = 0xFFFFF (4 KiB Granularity), present + * type = 32bit code execute/read, DPL = 0 + */ + .word 0xFFFF, 0 + .byte 0, 0x9A, 0xCF, 0 + + /* -- data segment -- + * base = 0x00000000, limit 0xFFFFF (4 KiB Granularity), present + * type = 32 bit data read/write, DPL = 0 + */ + .word 0xFFFF, 0 + .byte 0, 0x92, 0xCF, 0 + + .p2align 3 +/* this is the GDT descriptor */ +gdtdesc: + .word 0x17 /* limit */ + .long gdt /* addr */ + + .p2align 2 +/* Saved pointer to start info structure. */ + .globl pvh_start_info +pvh_start_info: + .long 0 + + .bss + .space GRUB_MEMORY_MACHINE_PROT_STACK_SIZE +LOCAL(stack_end): |