From 70bc2ef25ce55dbe80574d7918c7fcb0ca42b881 Mon Sep 17 00:00:00 2001 From: bean Date: Tue, 29 Jan 2008 10:59:56 +0000 Subject: [PATCH] 2008-01-29 Bean * 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. --- ChangeLog | 6 ++ boot/i386/pc/lnxboot.S | 145 +++++++++++++++++++++-------------------- 2 files changed, 79 insertions(+), 72 deletions(-) diff --git a/ChangeLog b/ChangeLog index ecc016a51..8cd297bc6 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,9 @@ +2008-01-29 Bean + + * 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 * conf/i386-pc.rmk (pkglib_MODULES): Add `png.mod'. diff --git a/boot/i386/pc/lnxboot.S b/boot/i386/pc/lnxboot.S index f1a4ded43..6a4de8dd5 100644 --- a/boot/i386/pc/lnxboot.S +++ b/boot/i386/pc/lnxboot.S @@ -1,7 +1,7 @@ /* -*-Asm-*- */ /* * 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 * it under the terms of the GNU General Public License as published by @@ -20,6 +20,7 @@ #include #include #include +#include .file "lnxboot.S" @@ -36,22 +37,7 @@ .globl start, _start data_start: - pushw %cs - 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) - + xorl %ebp, %ebp jmp linux_next . = data_start + 0x1F1 @@ -76,29 +62,29 @@ boot_flag: start: _start: - jmp linux_code + jmp linux_init - .ascii "HdrS" // Header signature - .word 0x0203 // Header version number + .ascii "HdrS" /* Header signature. */ + .word 0x0203 /* Header version number. */ realmode_swtch: - .word 0, 0 // default_switch, SETUPSEG + .word 0, 0 /* default_switch, SETUPSEG. */ start_sys_seg: - .word 0x1000 // obsolete + .word 0x1000 /* Obsolete. */ version_ptr: - .word 0 // version string ptr + .word 0 /* Version string ptr. */ type_of_loader: - .byte 0 // Filled in by boot loader + .byte 0 /* Filled in by boot loader. */ loadflags: - .byte 1 // Please load high + .byte 1 /* Please load high. */ setup_move_size: - .word 0 // Unused + .word 0 /* Unused. */ code32_start: - .long 0x100000 // 32-bit start address + .long 0x100000 /* 32-bit start address. */ ramdisk_image: - .long 0 // Loaded ramdisk image address + .long 0 /* Loaded ramdisk image address. */ ramdisk_size: - .long 0 // Size of loaded ramdisk + .long 0 /* Size of loaded ramdisk. */ bootsect_kludge: .word 0, 0 heap_end_ptr: @@ -106,27 +92,27 @@ heap_end_ptr: pad1: .word 0 cmd_line_ptr: - .long 0 // Command line + .long 0 /* Command line. */ ramdisk_max: - .long 0xffffffff // Highest allowed ramdisk address + .long 0xffffffff /* Highest allowed ramdisk address. */ gdt: - .long 0, 0, 0, 0 // Must be zero - .word 0xffff // 64 K segment size + .long 0, 0, 0, 0 /* Must be zero. */ + .word 0xffff /* 64 K segment size. */ gdt_src1: - .byte 0, 0 ,0 // Low 24 bits of source addy - .byte 0x93 // Access rights - .byte 0 // Extended access rights + .byte 0, 0 ,0 /* Low 24 bits of source address. */ + .byte 0x93 /* Access rights. */ + .byte 0 /* Extended access rights. */ gdt_src2: - .byte 0 // High 8 bits of source addy - .word 0xffff // 64 K segment size + .byte 0 /* High 8 bits of source address. */ + .word 0xffff /* 64 K segment size. */ gdt_dst1: - .byte 0, 0, 0 // Low 24 bits of target addy - .byte 0x93 // Access rights - .byte 0 // Extended access rights + .byte 0, 0, 0 /* Low 24 bits of target address. */ + .byte 0x93 /* Access rights. */ + .byte 0 /* Extended access rights. */ gdt_dst2: - .byte 0 // High 8 bits of source addy - .long 0, 0, 0, 0 // More space for the BIOS + .byte 0 /* High 8 bits of source address. */ + .long 0, 0, 0, 0 /* More space for the BIOS. */ reg_edx: .byte 0x80,0,0xFF,0xFF @@ -134,9 +120,10 @@ reg_edx: data_leng: .long 0 -linux_code: +linux_init: movw %cs:(reg_edx - start), %dx + movl %cs:(code32_start - start), %ebp linux_next: @@ -150,7 +137,7 @@ normalize: addw %bx, %ax pushw %ax pushw $(real_code - start) - lret // jump to real_code + lret /* Jump to real_code. */ real_code: subw $0x20, %ax @@ -158,16 +145,13 @@ real_code: movw (setup_sects - data_start), %cx shlw $7, %cx - // Setup stack + /* Setup stack. */ xorw %si, %si movw %si, %ss movw $(CODE_ADDR), %sp - pushl %esi - pushl %edi - - // Move itself to 0:CODE_ADDR + /* Move itself to 0:CODE_ADDR. */ cld movw %cs, %ax @@ -183,41 +167,55 @@ real_code: real_code_2: + xchgl %ebp, %esi + orl %esi, %esi + jnz 1f + movw %ds, %si + shll $4, %esi + addl %ebp, %esi +1: + pushw %es popw %ds - movl (ramdisk_image - start), %esi - or %esi, %esi - jnz 1f - movl (code32_start - start), %esi -1: - movl $0x200, %ecx addl %ecx, %esi movl $DATA_ADDR, %edi 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 movl %eax, %ss:(DATA_ADDR + GRUB_KERNEL_MACHINE_INSTALL_DOS_PART) movsbl (reg_edx + 2 - start), %eax 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 -// Parameters: -// esi: source address -// edi: target address -// ecx: number of bytes +/* + * Parameters: + * esi: source address + * edi: target address + * ecx: number of bytes + */ + move_memory: incl %ecx andb $0xFE, %cl @@ -261,8 +259,8 @@ move_memory: 2: - leal (%esi, %eax), %esi - leal (%edi, %eax), %edi + addl %eax, %esi + addl %eax, %edi subl %eax, %ecx jnz 1b @@ -270,8 +268,11 @@ move_memory: popw %dx ret -// Parameters: -// si: message +/* + * Parameters: + * si: message + */ + fail: movb $0x0e, %ah xorw %bx, %bx