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Diffstat (limited to 'stage2/nbloader.S')
| -rw-r--r-- | stage2/nbloader.S | 121 |
1 files changed, 0 insertions, 121 deletions
diff --git a/stage2/nbloader.S b/stage2/nbloader.S deleted file mode 100644 index 57ad936..0000000 --- a/stage2/nbloader.S +++ /dev/null @@ -1,121 +0,0 @@ -/* - * GRUB -- GRand Unified Bootloader - * Copyright (C) 2000 Free Software Foundation, Inc. - * - * 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, write to the Free Software - * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - */ - -#include <nbi.h> -#include <diskless_size.h> - - .file "nbloader.S" - .text - .code16 - - /* Just a dummy entry */ -.globl _start; _start: - - /* - * netboot image header - */ - - .long NBI_MAGIC - .long 0x00000004 - /* load address of the first block */ - .word NBI_DEST_OFF - .word NBI_DEST_SEG - /* start addr of the relocation code */ - .word NBI_DEST_OFF + (relocate - _start) - .word NBI_DEST_SEG - - .long 0x04000004 - .long NBI_DEST_ADDR + 0x0200 - .long DISKLESS_SIZE - .long DISKLESS_SIZE - -relocate: - /* - * This code is for now located at 0x10000. - * Relocate the code in two steps: - * 1. Copy the first 32k to 0x8000 and jump to the relocated area. - * 2. Copy the rest to 0x10000 (0x8000 + 32k). - */ - - /* Copy the first 32k */ - movw $NBI_DEST_SEG, %ax - movw %ax, %ds - movw $RELOCATED_SEG, %ax - movw %ax, %es - xorw %si, %si - xorw %di, %di - /* Always copy 32k bytes */ - movw $0x4000, %cx - - cld - rep - movsw - - /* Jump to the relocated address */ - ljmp $0, $(RELOCATED_ADDR + copy_rest - _start) - - /* Copy the rest */ -copy_rest: - /* Set %edx to the number of bytes */ - movl $(DISKLESS_SIZE + 0x200 - 0x8000), %edx - -copy_loop: - /* Check the rest */ - orl %edx, %edx - jz boot_stage2 - - /* Copy by 32k, as that is easy to implement */ - movl $0x8000, %ecx - cmpl %ecx, %edx - jg copy - movl %edx, %ecx - -copy: - /* Update the number of rest bytes */ - subl %ecx, %edx - - /* Add 0x0800 (32k >> 4) into %es and %ds */ - movw %es, %ax - addw $0x0800, %ax - movw %ax, %es - movw %ds, %ax - addw $0x800, %ax - movw %ax, %ds - - /* Zero the offsets */ - xorw %si, %si - xorw %di, %di - - /* Use word-size copy */ - addw $1, %cx - shrw $1, %cx - - /* The direction is already correct */ - rep - movsw - - jmp copy_loop - - /* Jump to the stage2 */ -boot_stage2: - ljmp $0, $STAGE2_START_ADDR - - /* This ensures that the length of this image will be 1 sector */ - . = _start + 0x200 - 1 - .byte 0 |