diff options
Diffstat (limited to 'qemu/pc-bios/optionrom/linuxboot.S')
| -rw-r--r-- | qemu/pc-bios/optionrom/linuxboot.S | 195 |
1 files changed, 0 insertions, 195 deletions
diff --git a/qemu/pc-bios/optionrom/linuxboot.S b/qemu/pc-bios/optionrom/linuxboot.S deleted file mode 100644 index ba821ab92..000000000 --- a/qemu/pc-bios/optionrom/linuxboot.S +++ /dev/null @@ -1,195 +0,0 @@ -/* - * Linux Boot 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> - * - * Based on code in hw/pc.c. - */ - -#include "optionrom.h" - -#define BOOT_ROM_PRODUCT "Linux loader" - -BOOT_ROM_START - -run_linuxboot: - - cli - cld - - jmp copy_kernel -boot_kernel: - - read_fw FW_CFG_SETUP_ADDR - - mov %eax, %ebx - shr $4, %ebx - - /* All segments contain real_addr */ - mov %bx, %ds - mov %bx, %es - mov %bx, %fs - mov %bx, %gs - mov %bx, %ss - - /* CX = CS we want to jump to */ - add $0x20, %bx - mov %bx, %cx - - /* SP = cmdline_addr-real_addr-16 */ - read_fw FW_CFG_CMDLINE_ADDR - mov %eax, %ebx - read_fw FW_CFG_SETUP_ADDR - sub %eax, %ebx - sub $16, %ebx - mov %ebx, %esp - - /* Build indirect lret descriptor */ - pushw %cx /* CS */ - xor %ax, %ax - pushw %ax /* IP = 0 */ - - /* Clear registers */ - xor %eax, %eax - xor %ebx, %ebx - xor %ecx, %ecx - xor %edx, %edx - xor %edi, %edi - xor %ebp, %ebp - - /* Jump to Linux */ - lret - - -copy_kernel: - /* Read info block in low memory (0x10000 or 0x90000) */ - read_fw FW_CFG_SETUP_ADDR - shr $4, %eax - mov %eax, %es - xor %edi, %edi - read_fw_blob_addr32_edi(FW_CFG_SETUP) - - cmpw $0x203, %es:0x206 // if protocol >= 0x203 - jae 1f // have initrd_max - movl $0x37ffffff, %es:0x22c // else assume 0x37ffffff -1: - - /* Check if using kernel-specified initrd address */ - read_fw FW_CFG_INITRD_ADDR - mov %eax, %edi // (load_kernel wants it in %edi) - read_fw FW_CFG_INITRD_SIZE // find end of initrd - add %edi, %eax - xor %es:0x22c, %eax // if it matches es:0x22c - and $-4096, %eax // (apart from padding for page) - jz load_kernel // then initrd is not at top - // of memory - - /* pc.c placed the initrd at end of memory. Compute a better - * initrd address based on e801 data. - */ - mov $0xe801, %ax - xor %cx, %cx - xor %dx, %dx - int $0x15 - - /* Output could be in AX/BX or CX/DX */ - or %cx, %cx - jnz 1f - or %dx, %dx - jnz 1f - mov %ax, %cx - mov %bx, %dx -1: - - or %dx, %dx - jnz 2f - addw $1024, %cx /* add 1 MB */ - movzwl %cx, %edi - shll $10, %edi /* convert to bytes */ - jmp 3f - -2: - addw $16777216 >> 16, %dx /* add 16 MB */ - movzwl %dx, %edi - shll $16, %edi /* convert to bytes */ - -3: - read_fw FW_CFG_INITRD_SIZE - subl %eax, %edi - andl $-4096, %edi /* EDI = start of initrd */ - movl %edi, %es:0x218 /* put it in the header */ - -load_kernel: - /* We need to load the kernel into memory we can't access in 16 bit - mode, so let's get into 32 bit mode, write the kernel and jump - back again. */ - - /* Reserve space on the stack for our GDT descriptor. */ - mov %esp, %ebp - sub $16, %esp - - /* Now create the GDT descriptor */ - movw $((3 * 8) - 1), -16(%bp) - mov %cs, %eax - movzwl %ax, %eax - shl $4, %eax - addl $gdt, %eax - movl %eax, -14(%bp) - - /* And load the GDT */ - data32 lgdt -16(%bp) - mov %ebp, %esp - - /* Get us to protected mode now */ - mov $1, %eax - mov %eax, %cr0 - - /* So we can set ES to a 32-bit segment */ - mov $0x10, %eax - mov %eax, %es - - /* We're now running in 16-bit CS, but 32-bit ES! */ - - /* Load kernel and initrd */ - read_fw_blob_addr32_edi(FW_CFG_INITRD) - read_fw_blob_addr32(FW_CFG_KERNEL) - read_fw_blob_addr32(FW_CFG_CMDLINE) - - /* And now jump into Linux! */ - mov $0, %eax - mov %eax, %cr0 - - /* ES = CS */ - mov %cs, %ax - mov %ax, %es - - jmp boot_kernel - -/* Variables */ - -.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 - -BOOT_ROM_END |