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2008-01-29 Bean <bean123ch@gmail.com>

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* boot/i386/pc/lnxboot.S (data_start): Code cleanup.
        (real_code_2): Code cleanup and change comment style.
        (move_memory): Avoid using 32-bit address mode.
This commit is contained in:
bean 2008-01-29 10:59:56 +00:00
parent 6a4d50ead0
commit 70bc2ef25c
2 changed files with 79 additions and 72 deletions
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6
ChangeLog
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@ -1,3 +1,9 @@
2008-01-29 Bean <bean123ch@gmail.com>
* boot/i386/pc/lnxboot.S (data_start): Code cleanup.
(real_code_2): Code cleanup and change comment style.
(move_memory): Avoid using 32-bit address mode.
2008-01-29 Bean <bean123ch@gmail.com> 2008-01-29 Bean <bean123ch@gmail.com>
* conf/i386-pc.rmk (pkglib_MODULES): Add `png.mod'. * conf/i386-pc.rmk (pkglib_MODULES): Add `png.mod'.

145
boot/i386/pc/lnxboot.S
View file

@ -1,7 +1,7 @@
/* -*-Asm-*- */ /* -*-Asm-*- */
/* /*
* GRUB -- GRand Unified Bootloader * GRUB -- GRand Unified Bootloader
* Copyright (C) 1999,2000,2001,2002,2005,2006,2007 Free Software Foundation, Inc. * Copyright (C) 2007,2008 Free Software Foundation, Inc.
* *
* GRUB is free software: you can redistribute it and/or modify * GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by * it under the terms of the GNU General Public License as published by
@ -20,6 +20,7 @@
#include <grub/boot.h> #include <grub/boot.h>
#include <grub/machine/boot.h> #include <grub/machine/boot.h>
#include <grub/machine/kernel.h> #include <grub/machine/kernel.h>
#include <multiboot.h>
.file "lnxboot.S" .file "lnxboot.S"
@ -36,22 +37,7 @@
.globl start, _start .globl start, _start
data_start: data_start:
pushw %cs xorl %ebp, %ebp
popw %ds
xorl %eax, %eax
xorl %ebx, %ebx
call data_next
data_next:
popw %bx
movw %cs, %ax
shll $4, %eax
leal 0x200 + data_start - data_next(%ebx,%eax), %eax
movzbl setup_sects - data_next(%bx), %ecx
shll $9, %ecx
addl %ecx, %eax
movl %eax, code32_start - data_next(%bx)
jmp linux_next jmp linux_next
. = data_start + 0x1F1 . = data_start + 0x1F1
@ -76,29 +62,29 @@ boot_flag:
start: start:
_start: _start:
jmp linux_code jmp linux_init
.ascii "HdrS" // Header signature .ascii "HdrS" /* Header signature. */
.word 0x0203 // Header version number .word 0x0203 /* Header version number. */
realmode_swtch: realmode_swtch:
.word 0, 0 // default_switch, SETUPSEG .word 0, 0 /* default_switch, SETUPSEG. */
start_sys_seg: start_sys_seg:
.word 0x1000 // obsolete .word 0x1000 /* Obsolete. */
version_ptr: version_ptr:
.word 0 // version string ptr .word 0 /* Version string ptr. */
type_of_loader: type_of_loader:
.byte 0 // Filled in by boot loader .byte 0 /* Filled in by boot loader. */
loadflags: loadflags:
.byte 1 // Please load high .byte 1 /* Please load high. */
setup_move_size: setup_move_size:
.word 0 // Unused .word 0 /* Unused. */
code32_start: code32_start:
.long 0x100000 // 32-bit start address .long 0x100000 /* 32-bit start address. */
ramdisk_image: ramdisk_image:
.long 0 // Loaded ramdisk image address .long 0 /* Loaded ramdisk image address. */
ramdisk_size: ramdisk_size:
.long 0 // Size of loaded ramdisk .long 0 /* Size of loaded ramdisk. */
bootsect_kludge: bootsect_kludge:
.word 0, 0 .word 0, 0
heap_end_ptr: heap_end_ptr:
@ -106,27 +92,27 @@ heap_end_ptr:
pad1: pad1:
.word 0 .word 0
cmd_line_ptr: cmd_line_ptr:
.long 0 // Command line .long 0 /* Command line. */
ramdisk_max: ramdisk_max:
.long 0xffffffff // Highest allowed ramdisk address .long 0xffffffff /* Highest allowed ramdisk address. */
gdt: gdt:
.long 0, 0, 0, 0 // Must be zero .long 0, 0, 0, 0 /* Must be zero. */
.word 0xffff // 64 K segment size .word 0xffff /* 64 K segment size. */
gdt_src1: gdt_src1:
.byte 0, 0 ,0 // Low 24 bits of source addy .byte 0, 0 ,0 /* Low 24 bits of source address. */
.byte 0x93 // Access rights .byte 0x93 /* Access rights. */
.byte 0 // Extended access rights .byte 0 /* Extended access rights. */
gdt_src2: gdt_src2:
.byte 0 // High 8 bits of source addy .byte 0 /* High 8 bits of source address. */
.word 0xffff // 64 K segment size .word 0xffff /* 64 K segment size. */
gdt_dst1: gdt_dst1:
.byte 0, 0, 0 // Low 24 bits of target addy .byte 0, 0, 0 /* Low 24 bits of target address. */
.byte 0x93 // Access rights .byte 0x93 /* Access rights. */
.byte 0 // Extended access rights .byte 0 /* Extended access rights. */
gdt_dst2: gdt_dst2:
.byte 0 // High 8 bits of source addy .byte 0 /* High 8 bits of source address. */
.long 0, 0, 0, 0 // More space for the BIOS .long 0, 0, 0, 0 /* More space for the BIOS. */
reg_edx: reg_edx:
.byte 0x80,0,0xFF,0xFF .byte 0x80,0,0xFF,0xFF
@ -134,9 +120,10 @@ reg_edx:
data_leng: data_leng:
.long 0 .long 0
linux_code: linux_init:
movw %cs:(reg_edx - start), %dx movw %cs:(reg_edx - start), %dx
movl %cs:(code32_start - start), %ebp
linux_next: linux_next:
@ -150,7 +137,7 @@ normalize:
addw %bx, %ax addw %bx, %ax
pushw %ax pushw %ax
pushw $(real_code - start) pushw $(real_code - start)
lret // jump to real_code lret /* Jump to real_code. */
real_code: real_code:
subw $0x20, %ax subw $0x20, %ax
@ -158,16 +145,13 @@ real_code:
movw (setup_sects - data_start), %cx movw (setup_sects - data_start), %cx
shlw $7, %cx shlw $7, %cx
// Setup stack /* Setup stack. */
xorw %si, %si xorw %si, %si
movw %si, %ss movw %si, %ss
movw $(CODE_ADDR), %sp movw $(CODE_ADDR), %sp
pushl %esi /* Move itself to 0:CODE_ADDR. */
pushl %edi
// Move itself to 0:CODE_ADDR
cld cld
movw %cs, %ax movw %cs, %ax
@ -183,41 +167,55 @@ real_code:
real_code_2: real_code_2:
xchgl %ebp, %esi
orl %esi, %esi
jnz 1f
movw %ds, %si
shll $4, %esi
addl %ebp, %esi
1:
pushw %es pushw %es
popw %ds popw %ds
movl (ramdisk_image - start), %esi
or %esi, %esi
jnz 1f
movl (code32_start - start), %esi
1:
movl $0x200, %ecx movl $0x200, %ecx
addl %ecx, %esi addl %ecx, %esi
movl $DATA_ADDR, %edi movl $DATA_ADDR, %edi
call move_memory call move_memory
/* Check for multiboot signature. */
cmpl $MULTIBOOT_MAGIC, %ss:(DATA_ADDR + 0x50)
jz 1f
movl (ramdisk_image - start), %esi
movl (ramdisk_size - start), %ecx
movl $(DATA_ADDR - 0x200), %edi
jmp 2f
1:
movl %ss:(DATA_ADDR + GRUB_KERNEL_MACHINE_COMPRESSED_SIZE), %ecx
addl $(GRUB_KERNEL_MACHINE_RAW_SIZE - 0x200), %ecx
2:
call move_memory
movsbl %dh, %eax movsbl %dh, %eax
movl %eax, %ss:(DATA_ADDR + GRUB_KERNEL_MACHINE_INSTALL_DOS_PART) movl %eax, %ss:(DATA_ADDR + GRUB_KERNEL_MACHINE_INSTALL_DOS_PART)
movsbl (reg_edx + 2 - start), %eax movsbl (reg_edx + 2 - start), %eax
movl %eax, %ss:(DATA_ADDR + GRUB_KERNEL_MACHINE_INSTALL_BSD_PART) movl %eax, %ss:(DATA_ADDR + GRUB_KERNEL_MACHINE_INSTALL_BSD_PART)
movl %ss:(DATA_ADDR + GRUB_KERNEL_MACHINE_COMPRESSED_SIZE), %ecx
addl $(GRUB_KERNEL_MACHINE_RAW_SIZE - 0x200), %ecx
call move_memory
popl %edi
popl %esi
ljmp $(DATA_ADDR >> 4), $0 ljmp $(DATA_ADDR >> 4), $0
// Parameters: /*
// esi: source address * Parameters:
// edi: target address * esi: source address
// ecx: number of bytes * edi: target address
* ecx: number of bytes
*/
move_memory: move_memory:
incl %ecx incl %ecx
andb $0xFE, %cl andb $0xFE, %cl
@ -261,8 +259,8 @@ move_memory:
2: 2:
leal (%esi, %eax), %esi addl %eax, %esi
leal (%edi, %eax), %edi addl %eax, %edi
subl %eax, %ecx subl %eax, %ecx
jnz 1b jnz 1b
@ -270,8 +268,11 @@ move_memory:
popw %dx popw %dx
ret ret
// Parameters: /*
// si: message * Parameters:
* si: message
*/
fail: fail:
movb $0x0e, %ah movb $0x0e, %ah
xorw %bx, %bx xorw %bx, %bx