c76386454e
* grub-core/kern/i386/pc/startup.S: Remove 0-data check. * grub-core/lib/reed_solomon.c (decode_block): Do not proceed on 0 data or 0 redundancy. (grub_reed_solomon_add_redundancy): Do not proceed with 0 redundancy. (grub_reed_solomon_recover): Likewise.
1011 lines
19 KiB
ArmAsm
1011 lines
19 KiB
ArmAsm
/*
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* GRUB -- GRand Unified Bootloader
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* Copyright (C) 1999,2000,2001,2002,2003,2005,2006,2007,2008,2009 Free Software Foundation, Inc.
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*
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* GRUB is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* GRUB is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
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*/
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/*
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* Note: These functions defined in this file may be called from C.
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* Be careful of that you must not modify some registers. Quote
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* from gcc-2.95.2/gcc/config/i386/i386.h:
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1 for registers not available across function calls.
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These must include the FIXED_REGISTERS and also any
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registers that can be used without being saved.
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The latter must include the registers where values are returned
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and the register where structure-value addresses are passed.
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Aside from that, you can include as many other registers as you like.
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ax,dx,cx,bx,si,di,bp,sp,st,st1,st2,st3,st4,st5,st6,st7,arg
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{ 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 }
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*/
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/*
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* Note: GRUB is compiled with the options -mrtd and -mregparm=3.
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* So the first three arguments are passed in %eax, %edx, and %ecx,
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* respectively, and if a function has a fixed number of arguments
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* and the number is greater than three, the function must return
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* with "ret $N" where N is ((the number of arguments) - 3) * 4.
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*/
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#include <config.h>
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#include <grub/symbol.h>
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#include <grub/boot.h>
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#include <grub/machine/boot.h>
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#include <grub/machine/memory.h>
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#include <grub/machine/console.h>
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#include <grub/cpu/linux.h>
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#include <grub/machine/kernel.h>
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#include <grub/term.h>
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#include <multiboot.h>
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#include <multiboot2.h>
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#define ABS(x) ((x) - LOCAL (base) + GRUB_BOOT_MACHINE_KERNEL_ADDR + 0x200)
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.file "startup.S"
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.text
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/* Tell GAS to generate 16-bit instructions so that this code works
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in real mode. */
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.code16
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.globl start, _start
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start:
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_start:
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LOCAL (base):
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/*
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* Guarantee that "main" is loaded at 0x0:0x8200.
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*/
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#ifdef __APPLE__
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ljmp $0, $(ABS(LOCAL (codestart)) - 0x10000)
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#else
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ljmp $0, $ABS(LOCAL (codestart))
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#endif
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/*
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* Compatibility version number
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*
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* These MUST be at byte offset 6 and 7 of the executable
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* DO NOT MOVE !!!
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*/
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. = _start + 0x6
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.byte GRUB_BOOT_VERSION_MAJOR, GRUB_BOOT_VERSION_MINOR
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/*
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* This is a special data area 8 bytes from the beginning.
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*/
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. = _start + 0x8
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VARIABLE(grub_total_module_size)
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.long 0
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VARIABLE(grub_kernel_image_size)
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.long 0
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VARIABLE(grub_compressed_size)
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.long 0
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VARIABLE(grub_install_dos_part)
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.long 0xFFFFFFFF
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VARIABLE(grub_install_bsd_part)
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.long 0xFFFFFFFF
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reed_solomon_redundancy:
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.long 0
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#ifdef APPLE_CC
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bss_start:
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.long 0
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bss_end:
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.long 0
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#endif
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/*
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* This is the area for all of the special variables.
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*/
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VARIABLE(grub_boot_drive)
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.byte 0
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/* the real mode code continues... */
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LOCAL (codestart):
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cli /* we're not safe here! */
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/* set up %ds, %ss, and %es */
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xorw %ax, %ax
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movw %ax, %ds
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movw %ax, %ss
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movw %ax, %es
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/* set up the real mode/BIOS stack */
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movl $GRUB_MEMORY_MACHINE_REAL_STACK, %ebp
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movl %ebp, %esp
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sti /* we're safe again */
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/* save the boot drive */
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ADDR32 movb %dl, EXT_C(grub_boot_drive)
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/* reset disk system (%ah = 0) */
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int $0x13
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/* transition to protected mode */
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DATA32 call real_to_prot
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/* The ".code32" directive takes GAS out of 16-bit mode. */
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.code32
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incl %eax
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call grub_gate_a20
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movl EXT_C(grub_compressed_size), %edx
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addl $(GRUB_KERNEL_MACHINE_RAW_SIZE - GRUB_KERNEL_I386_PC_NO_REED_SOLOMON_PART), %edx
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movl reed_solomon_redundancy, %ecx
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leal _start + GRUB_KERNEL_I386_PC_NO_REED_SOLOMON_PART, %eax
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call EXT_C (grub_reed_solomon_recover)
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jmp post_reed_solomon
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#include <rs_decoder.S>
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.text
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. = _start + GRUB_KERNEL_I386_PC_NO_REED_SOLOMON_PART
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/*
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* Support for booting GRUB from a Multiboot boot loader (e.g. GRUB itself).
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* This uses the a.out kludge to load raw binary to the area starting at 1MB,
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* and relocates itself after loaded.
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*/
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.p2align 2 /* force 4-byte alignment */
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multiboot_header:
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/* magic */
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.long 0x1BADB002
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/* flags */
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.long (1 << 16)
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/* checksum */
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.long -0x1BADB002 - (1 << 16)
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/* header addr */
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.long multiboot_header - _start + 0x100000 + 0x200
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/* load addr */
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.long 0x100000
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/* load end addr */
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.long 0
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/* bss end addr */
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.long 0
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/* entry addr */
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.long multiboot_entry - _start + 0x100000 + 0x200
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multiboot_entry:
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.code32
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/* obtain the boot device */
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movl 12(%ebx), %edx
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movl $GRUB_MEMORY_MACHINE_PROT_STACK, %ebp
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movl %ebp, %esp
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/* relocate the code */
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movl $(GRUB_KERNEL_MACHINE_RAW_SIZE + 0x200), %ecx
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addl EXT_C(grub_compressed_size) - _start + 0x100000 + 0x200, %ecx
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movl $0x100000, %esi
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movl $GRUB_BOOT_MACHINE_KERNEL_ADDR, %edi
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cld
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rep
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movsb
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/* jump to the real address */
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movl $multiboot_trampoline, %eax
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jmp *%eax
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multiboot_trampoline:
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/* fill the boot information */
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movl %edx, %eax
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shrl $8, %eax
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xorl %ebx, %ebx
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cmpb $0xFF, %ah
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je 1f
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movb %ah, %bl
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movl %ebx, EXT_C(grub_install_dos_part)
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1:
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cmpb $0xFF, %al
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je 2f
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movb %al, %bl
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movl %ebx, EXT_C(grub_install_bsd_part)
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2:
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shrl $24, %edx
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movb $0xFF, %dh
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/* enter the usual booting */
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call prot_to_real
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jmp LOCAL (codestart)
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post_reed_solomon:
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#ifdef ENABLE_LZMA
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movl $GRUB_MEMORY_MACHINE_DECOMPRESSION_ADDR, %edi
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movl $(_start + GRUB_KERNEL_MACHINE_RAW_SIZE), %esi
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pushl %edi
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pushl %esi
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movl EXT_C(grub_kernel_image_size), %ecx
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addl EXT_C(grub_total_module_size), %ecx
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subl $GRUB_KERNEL_MACHINE_RAW_SIZE, %ecx
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pushl %ecx
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leal (%edi, %ecx), %ebx
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call _LzmaDecodeA
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/* _LzmaDecodeA clears DF, so no need to run cld */
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popl %ecx
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popl %edi
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popl %esi
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#endif
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/* copy back the decompressed part (except the modules) */
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subl EXT_C(grub_total_module_size), %ecx
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rep
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movsb
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#if 0
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/* copy modules before cleaning out the bss */
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movl EXT_C(grub_total_module_size), %ecx
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movl EXT_C(grub_kernel_image_size), %esi
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addl %ecx, %esi
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addl $_start, %esi
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decl %esi
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movl $END_SYMBOL, %edi
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addl %ecx, %edi
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decl %edi
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std
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rep
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movsb
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#endif
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#ifdef APPLE_CC
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/* clean out the bss */
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bss_start_abs = ABS (bss_start)
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bss_end_abs = ABS (bss_end)
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movl bss_start_abs, %edi
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/* compute the bss length */
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movl bss_end_abs, %ecx
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subl %edi, %ecx
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#else
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/* clean out the bss */
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movl $BSS_START_SYMBOL, %edi
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/* compute the bss length */
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movl $END_SYMBOL, %ecx
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subl %edi, %ecx
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#endif
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/* clean out */
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xorl %eax, %eax
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cld
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rep
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stosb
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/*
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* Call the start of main body of C code.
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*/
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call EXT_C(grub_main)
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#include "../realmode.S"
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/*
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* grub_gate_a20(int on)
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*
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* Gate address-line 20 for high memory.
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*
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* This routine is probably overconservative in what it does, but so what?
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*
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* It also eats any keystrokes in the keyboard buffer. :-(
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*/
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grub_gate_a20:
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movl %eax, %edx
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gate_a20_test_current_state:
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/* first of all, test if already in a good state */
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call gate_a20_check_state
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cmpb %al, %dl
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jnz gate_a20_try_bios
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ret
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gate_a20_try_bios:
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/* second, try a BIOS call */
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pushl %ebp
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call prot_to_real
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.code16
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movw $0x2400, %ax
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testb %dl, %dl
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jz 1f
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incw %ax
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1: int $0x15
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DATA32 call real_to_prot
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.code32
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popl %ebp
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call gate_a20_check_state
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cmpb %al, %dl
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jnz gate_a20_try_system_control_port_a
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ret
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gate_a20_try_system_control_port_a:
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/*
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* In macbook, the keyboard test would hang the machine, so we move
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* this forward.
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*/
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/* fourth, try the system control port A */
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inb $0x92
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andb $(~0x03), %al
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testb %dl, %dl
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jz 6f
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orb $0x02, %al
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6: outb $0x92
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/* When turning off Gate A20, do not check the state strictly,
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because a failure is not fatal usually, and Gate A20 is always
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on some modern machines. */
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testb %dl, %dl
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jz 7f
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call gate_a20_check_state
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cmpb %al, %dl
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jnz gate_a20_try_keyboard_controller
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7: ret
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gate_a20_flush_keyboard_buffer:
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inb $0x64
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andb $0x02, %al
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jnz gate_a20_flush_keyboard_buffer
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2:
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inb $0x64
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andb $0x01, %al
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jz 3f
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inb $0x60
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jmp 2b
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3:
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ret
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gate_a20_try_keyboard_controller:
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/* third, try the keyboard controller */
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call gate_a20_flush_keyboard_buffer
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movb $0xd1, %al
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outb $0x64
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4:
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inb $0x64
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andb $0x02, %al
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jnz 4b
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movb $0xdd, %al
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testb %dl, %dl
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jz 5f
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orb $0x02, %al
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5: outb $0x60
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call gate_a20_flush_keyboard_buffer
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/* output a dummy command (USB keyboard hack) */
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movb $0xff, %al
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outb $0x64
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call gate_a20_flush_keyboard_buffer
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call gate_a20_check_state
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cmpb %al, %dl
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/* everything failed, so restart from the beginning */
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jnz gate_a20_try_bios
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ret
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gate_a20_check_state:
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/* iterate the checking for a while */
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movl $100, %ecx
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1:
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call 3f
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cmpb %al, %dl
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jz 2f
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loop 1b
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2:
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ret
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3:
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pushl %ebx
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pushl %ecx
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xorl %eax, %eax
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/* compare the byte at 0x8000 with that at 0x108000 */
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movl $GRUB_BOOT_MACHINE_KERNEL_ADDR, %ebx
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pushl %ebx
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/* save the original byte in CL */
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movb (%ebx), %cl
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/* store the value at 0x108000 in AL */
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addl $0x100000, %ebx
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movb (%ebx), %al
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/* try to set one less value at 0x8000 */
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popl %ebx
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movb %al, %ch
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decb %ch
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movb %ch, (%ebx)
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/* serialize */
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outb %al, $0x80
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outb %al, $0x80
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/* obtain the value at 0x108000 in CH */
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pushl %ebx
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addl $0x100000, %ebx
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movb (%ebx), %ch
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/* this result is 1 if A20 is on or 0 if it is off */
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subb %ch, %al
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xorb $1, %al
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/* restore the original */
|
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popl %ebx
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movb %cl, (%ebx)
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popl %ecx
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popl %ebx
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ret
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|
|
#ifdef ENABLE_LZMA
|
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#include "lzma_decode.S"
|
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#endif
|
|
|
|
/*
|
|
* The code beyond this point is compressed. Assert that the uncompressed
|
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* code fits GRUB_KERNEL_MACHINE_RAW_SIZE.
|
|
*/
|
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. = _start + GRUB_KERNEL_MACHINE_RAW_SIZE
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|
|
|
. = _start + GRUB_KERNEL_MACHINE_PREFIX
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VARIABLE(grub_prefix)
|
|
/* to be filled by grub-mkimage */
|
|
|
|
/*
|
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* Leave some breathing room for the prefix.
|
|
*/
|
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. = _start + GRUB_KERNEL_MACHINE_PREFIX_END
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|
|
|
|
|
|
|
/*
|
|
* grub_exit()
|
|
*
|
|
* Exit the system.
|
|
*/
|
|
FUNCTION(grub_exit)
|
|
call prot_to_real
|
|
.code16
|
|
/* Tell the BIOS a boot failure. If this does not work, reboot. */
|
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int $0x18
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|
jmp cold_reboot
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|
.code32
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|
|
|
/*
|
|
* void grub_chainloader_real_boot (int drive, void *part_addr)
|
|
*
|
|
* This starts another boot loader.
|
|
*/
|
|
|
|
FUNCTION(grub_chainloader_real_boot)
|
|
pushl %edx
|
|
pushl %eax
|
|
|
|
/* Turn off Gate A20 */
|
|
xorl %eax, %eax
|
|
call grub_gate_a20
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|
|
|
/* set up to pass boot drive */
|
|
popl %edx
|
|
|
|
/* ESI must point to a partition table entry */
|
|
popl %esi
|
|
|
|
call prot_to_real
|
|
.code16
|
|
ljmp $0, $GRUB_MEMORY_MACHINE_BOOT_LOADER_ADDR
|
|
.code32
|
|
|
|
/*
|
|
* void grub_console_putchar (int c)
|
|
*
|
|
* Put the character C on the console. Because GRUB wants to write a
|
|
* character with an attribute, this implementation is a bit tricky.
|
|
* If C is a control character (CR, LF, BEL, BS), use INT 10, AH = 0Eh
|
|
* (TELETYPE OUTPUT). Otherwise, save the original position, put a space,
|
|
* save the current position, restore the original position, write the
|
|
* character and the attribute, and restore the current position.
|
|
*
|
|
* The reason why this is so complicated is that there is no easy way to
|
|
* get the height of the screen, and the TELETYPE OUTPUT BIOS call doesn't
|
|
* support setting a background attribute.
|
|
*/
|
|
FUNCTION(grub_console_putchar)
|
|
/* Retrieve the base character. */
|
|
movl 0(%edx), %edx
|
|
pusha
|
|
movb EXT_C(grub_console_cur_color), %bl
|
|
|
|
call prot_to_real
|
|
.code16
|
|
movb %dl, %al
|
|
xorb %bh, %bh
|
|
|
|
/* use teletype output if control character */
|
|
cmpb $0x7, %al
|
|
je 1f
|
|
cmpb $0x8, %al
|
|
je 1f
|
|
cmpb $0xa, %al
|
|
je 1f
|
|
cmpb $0xd, %al
|
|
je 1f
|
|
|
|
/* save the character and the attribute on the stack */
|
|
pushw %ax
|
|
pushw %bx
|
|
|
|
/* get the current position */
|
|
movb $0x3, %ah
|
|
int $0x10
|
|
|
|
/* check the column with the width */
|
|
cmpb $79, %dl
|
|
jl 2f
|
|
|
|
/* print CR and LF, if next write will exceed the width */
|
|
movw $0x0e0d, %ax
|
|
int $0x10
|
|
movb $0x0a, %al
|
|
int $0x10
|
|
|
|
/* get the current position */
|
|
movb $0x3, %ah
|
|
int $0x10
|
|
|
|
2:
|
|
/* restore the character and the attribute */
|
|
popw %bx
|
|
popw %ax
|
|
|
|
/* write the character with the attribute */
|
|
movb $0x9, %ah
|
|
movw $1, %cx
|
|
int $0x10
|
|
|
|
/* move the cursor forward */
|
|
incb %dl
|
|
movb $0x2, %ah
|
|
int $0x10
|
|
|
|
jmp 3f
|
|
|
|
1: movw $1, %bx
|
|
movb $0xe, %ah
|
|
int $0x10
|
|
|
|
3: DATA32 call real_to_prot
|
|
.code32
|
|
|
|
popa
|
|
ret
|
|
|
|
|
|
LOCAL(bypass_table):
|
|
.word 0x011b, 0x0f00 | '\t', 0x0e00 | '\b', 0x1c00 | '\r'
|
|
.word 0x1c00 | '\n'
|
|
LOCAL(bypass_table_end):
|
|
|
|
/*
|
|
* int grub_console_getkey (void)
|
|
* if there is a character pending, return it; otherwise return -1
|
|
* BIOS call "INT 16H Function 01H" to check whether a character is pending
|
|
* Call with %ah = 0x1
|
|
* Return:
|
|
* If key waiting to be input:
|
|
* %ah = keyboard scan code
|
|
* %al = ASCII character
|
|
* Zero flag = clear
|
|
* else
|
|
* Zero flag = set
|
|
* BIOS call "INT 16H Function 00H" to read character from keyboard
|
|
* Call with %ah = 0x0
|
|
* Return: %ah = keyboard scan code
|
|
* %al = ASCII character
|
|
*/
|
|
|
|
FUNCTION(grub_console_getkey)
|
|
pushl %ebp
|
|
pushl %edi
|
|
|
|
call prot_to_real
|
|
.code16
|
|
|
|
/*
|
|
* Due to a bug in apple's bootcamp implementation, INT 16/AH = 0 would
|
|
* cause the machine to hang at the second keystroke. However, we can
|
|
* work around this problem by ensuring the presence of keystroke with
|
|
* INT 16/AH = 1 before calling INT 16/AH = 0.
|
|
*/
|
|
|
|
movb $1, %ah
|
|
int $0x16
|
|
jz notpending
|
|
|
|
movb $0, %ah
|
|
int $0x16
|
|
|
|
xorl %edx, %edx
|
|
movw %ax, %dx /* real_to_prot uses %eax */
|
|
|
|
DATA32 call real_to_prot
|
|
.code32
|
|
|
|
movl $0xff, %eax
|
|
testl %eax, %edx
|
|
jz 1f
|
|
|
|
andl %edx, %eax
|
|
cmpl $0x20, %eax
|
|
jae 2f
|
|
movl %edx, %eax
|
|
leal LOCAL(bypass_table), %edi
|
|
movl $((LOCAL(bypass_table_end) - LOCAL(bypass_table)) >> 1), %ecx
|
|
repne scasw
|
|
jz 3f
|
|
|
|
andl $0xff, %eax
|
|
addl $(('a' - 1) | GRUB_TERM_CTRL), %eax
|
|
jmp 2f
|
|
3:
|
|
andl $0xff, %eax
|
|
jmp 2f
|
|
|
|
1: movl %edx, %eax
|
|
shrl $8, %eax
|
|
orl $GRUB_TERM_EXTENDED, %eax
|
|
2:
|
|
popl %edi
|
|
popl %ebp
|
|
ret
|
|
|
|
notpending:
|
|
.code16
|
|
DATA32 call real_to_prot
|
|
.code32
|
|
#if GRUB_TERM_NO_KEY != 0
|
|
#error Fix this asm code
|
|
#endif
|
|
jmp 2b
|
|
|
|
|
|
/*
|
|
* grub_uint16_t grub_console_getxy (void)
|
|
* BIOS call "INT 10H Function 03h" to get cursor position
|
|
* Call with %ah = 0x03
|
|
* %bh = page
|
|
* Returns %ch = starting scan line
|
|
* %cl = ending scan line
|
|
* %dh = row (0 is top)
|
|
* %dl = column (0 is left)
|
|
*/
|
|
|
|
|
|
FUNCTION(grub_console_getxy)
|
|
pushl %ebp
|
|
pushl %ebx /* save EBX */
|
|
|
|
call prot_to_real
|
|
.code16
|
|
|
|
xorb %bh, %bh /* set page to 0 */
|
|
movb $0x3, %ah
|
|
int $0x10 /* get cursor position */
|
|
|
|
DATA32 call real_to_prot
|
|
.code32
|
|
|
|
movb %dl, %ah
|
|
movb %dh, %al
|
|
|
|
popl %ebx
|
|
popl %ebp
|
|
ret
|
|
|
|
|
|
/*
|
|
* void grub_console_gotoxy(grub_uint8_t x, grub_uint8_t y)
|
|
* BIOS call "INT 10H Function 02h" to set cursor position
|
|
* Call with %ah = 0x02
|
|
* %bh = page
|
|
* %dh = row (0 is top)
|
|
* %dl = column (0 is left)
|
|
*/
|
|
|
|
|
|
FUNCTION(grub_console_gotoxy)
|
|
pushl %ebp
|
|
pushl %ebx /* save EBX */
|
|
|
|
movb %cl, %dh /* %dh = y */
|
|
/* %dl = x */
|
|
|
|
call prot_to_real
|
|
.code16
|
|
|
|
xorb %bh, %bh /* set page to 0 */
|
|
movb $0x2, %ah
|
|
int $0x10 /* set cursor position */
|
|
|
|
DATA32 call real_to_prot
|
|
.code32
|
|
|
|
popl %ebx
|
|
popl %ebp
|
|
ret
|
|
|
|
|
|
/*
|
|
* void grub_console_cls (void)
|
|
* BIOS call "INT 10H Function 09h" to write character and attribute
|
|
* Call with %ah = 0x09
|
|
* %al = (character)
|
|
* %bh = (page number)
|
|
* %bl = (attribute)
|
|
* %cx = (number of times)
|
|
*/
|
|
|
|
FUNCTION(grub_console_cls)
|
|
pushl %ebp
|
|
pushl %ebx /* save EBX */
|
|
|
|
call prot_to_real
|
|
.code16
|
|
|
|
/* move the cursor to the beginning */
|
|
movb $0x02, %ah
|
|
xorb %bh, %bh
|
|
xorw %dx, %dx
|
|
int $0x10
|
|
|
|
/* write spaces to the entire screen */
|
|
movw $0x0920, %ax
|
|
movw $0x07, %bx
|
|
movw $(80 * 25), %cx
|
|
int $0x10
|
|
|
|
/* move back the cursor */
|
|
movb $0x02, %ah
|
|
int $0x10
|
|
|
|
DATA32 call real_to_prot
|
|
.code32
|
|
|
|
popl %ebx
|
|
popl %ebp
|
|
ret
|
|
|
|
|
|
/*
|
|
* void grub_console_setcursor (int on)
|
|
* BIOS call "INT 10H Function 01h" to set cursor type
|
|
* Call with %ah = 0x01
|
|
* %ch = cursor starting scanline
|
|
* %cl = cursor ending scanline
|
|
*/
|
|
|
|
console_cursor_state:
|
|
.byte 1
|
|
console_cursor_shape:
|
|
.word 0
|
|
|
|
FUNCTION(grub_console_setcursor)
|
|
pushl %ebp
|
|
pushl %ebx
|
|
|
|
/* push ON */
|
|
pushl %edx
|
|
|
|
/* check if the standard cursor shape has already been saved */
|
|
movw console_cursor_shape, %ax
|
|
testw %ax, %ax
|
|
jne 1f
|
|
|
|
call prot_to_real
|
|
.code16
|
|
|
|
movb $0x03, %ah
|
|
xorb %bh, %bh
|
|
int $0x10
|
|
|
|
DATA32 call real_to_prot
|
|
.code32
|
|
|
|
cmp %cl, %ch
|
|
jb 3f
|
|
movw $0x0d0e, %cx
|
|
3:
|
|
movw %cx, console_cursor_shape
|
|
1:
|
|
/* set %cx to the designated cursor shape */
|
|
movw $0x2000, %cx
|
|
popl %eax
|
|
testl %eax, %eax
|
|
jz 2f
|
|
movw console_cursor_shape, %cx
|
|
2:
|
|
call prot_to_real
|
|
.code16
|
|
|
|
movb $0x1, %ah
|
|
int $0x10
|
|
|
|
DATA32 call real_to_prot
|
|
.code32
|
|
|
|
popl %ebx
|
|
popl %ebp
|
|
ret
|
|
|
|
/*
|
|
* grub_get_rtc()
|
|
* return the real time in ticks, of which there are about
|
|
* 18-20 per second
|
|
*/
|
|
FUNCTION(grub_get_rtc)
|
|
pushl %ebp
|
|
|
|
call prot_to_real /* enter real mode */
|
|
.code16
|
|
|
|
/* %ax is already zero */
|
|
int $0x1a
|
|
|
|
DATA32 call real_to_prot
|
|
.code32
|
|
|
|
movl %ecx, %eax
|
|
shll $16, %eax
|
|
movw %dx, %ax
|
|
|
|
popl %ebp
|
|
ret
|
|
|
|
/*
|
|
* int grub_pxe_call (int func, void* data, grub_uint32_t pxe_rm_entry);
|
|
*/
|
|
FUNCTION(grub_pxe_call)
|
|
pushl %ebp
|
|
movl %esp, %ebp
|
|
pushl %esi
|
|
pushl %edi
|
|
pushl %ebx
|
|
|
|
movl %ecx, %ebx
|
|
movl %eax, %ecx
|
|
movl %edx, %eax
|
|
andl $0xF, %eax
|
|
shrl $4, %edx
|
|
shll $16, %edx
|
|
addl %eax, %edx
|
|
|
|
call prot_to_real
|
|
.code16
|
|
|
|
pushl %ebx
|
|
pushl %edx
|
|
pushw %cx
|
|
movw %sp, %bx
|
|
lcall *%ss:6(%bx)
|
|
cld
|
|
addw $10, %sp
|
|
movw %ax, %cx
|
|
|
|
DATA32 call real_to_prot
|
|
.code32
|
|
|
|
movzwl %cx, %eax
|
|
|
|
popl %ebx
|
|
popl %edi
|
|
popl %esi
|
|
popl %ebp
|
|
ret
|
|
|
|
FUNCTION(grub_bios_interrupt)
|
|
pushl %ebp
|
|
pushl %ecx
|
|
pushl %eax
|
|
pushl %ebx
|
|
pushl %esi
|
|
pushl %edi
|
|
pushl %edx
|
|
|
|
movb %al, intno
|
|
movl (%edx), %eax
|
|
movl %eax, LOCAL(bios_register_eax)
|
|
movw 4(%edx), %ax
|
|
movw %ax, LOCAL(bios_register_es)
|
|
movw 6(%edx), %ax
|
|
movw %ax, LOCAL(bios_register_ds)
|
|
movw 8(%edx), %ax
|
|
movw %ax, LOCAL(bios_register_flags)
|
|
|
|
movl 12(%edx), %ebx
|
|
movl 16(%edx), %ecx
|
|
movl 20(%edx), %edi
|
|
movl 24(%edx), %esi
|
|
movl 28(%edx), %edx
|
|
|
|
call prot_to_real
|
|
.code16
|
|
|
|
mov %ds, %ax
|
|
push %ax
|
|
|
|
/* movw imm16, %ax*/
|
|
.byte 0xb8
|
|
LOCAL(bios_register_es):
|
|
.short 0
|
|
movw %ax, %es
|
|
/* movw imm16, %ax*/
|
|
.byte 0xb8
|
|
LOCAL(bios_register_ds):
|
|
.short 0
|
|
movw %ax, %ds
|
|
|
|
/* movw imm16, %ax*/
|
|
.byte 0xb8
|
|
LOCAL(bios_register_flags):
|
|
.short 0
|
|
push %ax
|
|
popf
|
|
|
|
/* movl imm32, %eax*/
|
|
.byte 0x66, 0xb8
|
|
LOCAL(bios_register_eax):
|
|
.long 0
|
|
|
|
/* int imm8. */
|
|
.byte 0xcd
|
|
intno:
|
|
.byte 0
|
|
|
|
movl %eax, %cs:LOCAL(bios_register_eax)
|
|
movw %ds, %ax
|
|
movw %ax, %cs:LOCAL(bios_register_ds)
|
|
pop %ax
|
|
mov %ax, %ds
|
|
pushf
|
|
pop %ax
|
|
movw %ax, LOCAL(bios_register_flags)
|
|
mov %es, %ax
|
|
movw %ax, LOCAL(bios_register_es)
|
|
|
|
DATA32 call real_to_prot
|
|
.code32
|
|
|
|
popl %eax
|
|
|
|
movl %ebx, 12(%eax)
|
|
movl %ecx, 16(%eax)
|
|
movl %edi, 20(%eax)
|
|
movl %esi, 24(%eax)
|
|
movl %edx, 28(%eax)
|
|
|
|
movl %eax, %edx
|
|
|
|
movl LOCAL(bios_register_eax), %eax
|
|
movl %eax, (%edx)
|
|
movw LOCAL(bios_register_es), %ax
|
|
movw %ax, 4(%edx)
|
|
movw LOCAL(bios_register_ds), %ax
|
|
movw %ax, 6(%edx)
|
|
movw LOCAL(bios_register_flags), %ax
|
|
movw %ax, 8(%edx)
|
|
|
|
popl %edi
|
|
popl %esi
|
|
popl %ebx
|
|
popl %eax
|
|
popl %ecx
|
|
popl %ebp
|
|
ret
|