diff options
Diffstat (limited to 'qemu/pc-bios/optionrom/multiboot.S')
| -rw-r--r-- | qemu/pc-bios/optionrom/multiboot.S | 232 |
1 files changed, 0 insertions, 232 deletions
diff --git a/qemu/pc-bios/optionrom/multiboot.S b/qemu/pc-bios/optionrom/multiboot.S deleted file mode 100644 index b7efe4de3..000000000 --- a/qemu/pc-bios/optionrom/multiboot.S +++ /dev/null @@ -1,232 +0,0 @@ -/* - * Multiboot Option ROM - * - * This program 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 2 of the License, or - * (at your option) any later version. - * - * This program 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 this program; if not, see <http://www.gnu.org/licenses/>. - * - * Copyright Novell Inc, 2009 - * Authors: Alexander Graf <agraf@suse.de> - */ - -#include "optionrom.h" - -#define BOOT_ROM_PRODUCT "multiboot loader" - -#define MULTIBOOT_MAGIC 0x2badb002 - -#define GS_PROT_JUMP 0 -#define GS_GDT_DESC 6 - - -BOOT_ROM_START - -run_multiboot: - - cli - cld - - mov %cs, %eax - shl $0x4, %eax - - /* set up a long jump descriptor that is PC relative */ - - /* move stack memory to %gs */ - mov %ss, %ecx - shl $0x4, %ecx - mov %esp, %ebx - add %ebx, %ecx - sub $0x20, %ecx - sub $0x30, %esp - shr $0x4, %ecx - mov %cx, %gs - - /* now push the indirect jump descriptor there */ - mov (prot_jump), %ebx - add %eax, %ebx - movl %ebx, %gs:GS_PROT_JUMP - mov $8, %bx - movw %bx, %gs:GS_PROT_JUMP + 4 - - /* fix the gdt descriptor to be PC relative */ - movw (gdt_desc), %bx - movw %bx, %gs:GS_GDT_DESC - movl (gdt_desc+2), %ebx - add %eax, %ebx - movl %ebx, %gs:GS_GDT_DESC + 2 - - xor %eax, %eax - mov %eax, %es - - /* Read the bootinfo struct into RAM */ - read_fw_blob(FW_CFG_INITRD) - - /* FS = bootinfo_struct */ - read_fw FW_CFG_INITRD_ADDR - shr $4, %eax - mov %ax, %fs - - /* Account for the EBDA in the multiboot structure's e801 - * map. - */ - int $0x12 - cwtl - movl %eax, %fs:4 - - /* ES = mmap_addr */ - mov %fs:48, %eax - shr $4, %eax - mov %ax, %es - - /* Initialize multiboot mmap structs using int 0x15(e820) */ - xor %ebx, %ebx - /* Start storing mmap data at %es:0 */ - xor %edi, %edi - -mmap_loop: - /* The multiboot entry size has offset -4, so leave some space */ - add $4, %di - /* entry size (mmap struct) & max buffer size (int15) */ - movl $20, %ecx - /* e820 */ - movl $0x0000e820, %eax - /* 'SMAP' magic */ - movl $0x534d4150, %edx - int $0x15 - -mmap_check_entry: - /* Error or last entry already done? */ - jb mmap_done - -mmap_store_entry: - /* store entry size */ - /* old as(1) doesn't like this insn so emit the bytes instead: - movl %ecx, %es:-4(%edi) - */ - .dc.b 0x26,0x67,0x66,0x89,0x4f,0xfc - - /* %edi += entry_size, store as mbs_mmap_length */ - add %ecx, %edi - movw %di, %fs:0x2c - - /* Continuation value 0 means last entry */ - test %ebx, %ebx - jnz mmap_loop - -mmap_done: - /* Calculate upper_mem field: The amount of memory between 1 MB and - the first upper memory hole. Get it from the mmap. */ - xor %di, %di - mov $0x100000, %edx -upper_mem_entry: - cmp %fs:0x2c, %di - je upper_mem_done - add $4, %di - - /* Skip if type != 1 */ - cmpl $1, %es:16(%di) - jne upper_mem_next - - /* Skip if > 4 GB */ - movl %es:4(%di), %eax - test %eax, %eax - jnz upper_mem_next - - /* Check for contiguous extension (base <= %edx < base + length) */ - movl %es:(%di), %eax - cmp %eax, %edx - jb upper_mem_next - addl %es:8(%di), %eax - cmp %eax, %edx - jae upper_mem_next - - /* If so, update %edx, and restart the search (mmap isn't ordered) */ - mov %eax, %edx - xor %di, %di - jmp upper_mem_entry - -upper_mem_next: - addl %es:-4(%di), %edi - jmp upper_mem_entry - -upper_mem_done: - sub $0x100000, %edx - shr $10, %edx - mov %edx, %fs:0x8 - -real_to_prot: - /* Load the GDT before going into protected mode */ -lgdt: - data32 lgdt %gs:GS_GDT_DESC - - /* get us to protected mode now */ - movl $1, %eax - movl %eax, %cr0 - - /* the LJMP sets CS for us and gets us to 32-bit */ -ljmp: - data32 ljmp *%gs:GS_PROT_JUMP - -prot_mode: -.code32 - - /* initialize all other segments */ - movl $0x10, %eax - movl %eax, %ss - movl %eax, %ds - movl %eax, %es - movl %eax, %fs - movl %eax, %gs - - /* Read the kernel and modules into RAM */ - read_fw_blob(FW_CFG_KERNEL) - - /* Jump off to the kernel */ - read_fw FW_CFG_KERNEL_ENTRY - mov %eax, %ecx - - /* EBX contains a pointer to the bootinfo struct */ - read_fw FW_CFG_INITRD_ADDR - movl %eax, %ebx - - /* EAX has to contain the magic */ - movl $MULTIBOOT_MAGIC, %eax -ljmp2: - jmp *%ecx - -/* Variables */ -.align 4, 0 -prot_jump: .long prot_mode - .short 8 - -.align 4, 0 -gdt: - /* 0x00 */ -.byte 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 - - /* 0x08: code segment (base=0, limit=0xfffff, type=32bit code exec/read, DPL=0, 4k) */ -.byte 0xff, 0xff, 0x00, 0x00, 0x00, 0x9a, 0xcf, 0x00 - - /* 0x10: data segment (base=0, limit=0xfffff, type=32bit data read/write, DPL=0, 4k) */ -.byte 0xff, 0xff, 0x00, 0x00, 0x00, 0x92, 0xcf, 0x00 - - /* 0x18: code segment (base=0, limit=0x0ffff, type=16bit code exec/read/conf, DPL=0, 1b) */ -.byte 0xff, 0xff, 0x00, 0x00, 0x00, 0x9e, 0x00, 0x00 - - /* 0x20: data segment (base=0, limit=0x0ffff, type=16bit data read/write, DPL=0, 1b) */ -.byte 0xff, 0xff, 0x00, 0x00, 0x00, 0x92, 0x00, 0x00 - -gdt_desc: -.short (5 * 8) - 1 -.long gdt - -BOOT_ROM_END |