diff options
Diffstat (limited to 'contrib/syslinux/latest/mbr/isohdpfx.S')
| -rw-r--r-- | contrib/syslinux/latest/mbr/isohdpfx.S | 263 |
1 files changed, 0 insertions, 263 deletions
diff --git a/contrib/syslinux/latest/mbr/isohdpfx.S b/contrib/syslinux/latest/mbr/isohdpfx.S deleted file mode 100644 index 0bf807e..0000000 --- a/contrib/syslinux/latest/mbr/isohdpfx.S +++ /dev/null @@ -1,263 +0,0 @@ -/* ----------------------------------------------------------------------- - * - * Copyright 2007-2009 H. Peter Anvin - All Rights Reserved - * Copyright 2009 Intel Corporation; author: H. Peter Anvin - * - * Permission is hereby granted, free of charge, to any person - * obtaining a copy of this software and associated documentation - * files (the "Software"), to deal in the Software without - * restriction, including without limitation the rights to use, - * copy, modify, merge, publish, distribute, sublicense, and/or - * sell copies of the Software, and to permit persons to whom - * the Software is furnished to do so, subject to the following - * conditions: - * - * The above copyright notice and this permission notice shall - * be included in all copies or substantial portions of the Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, - * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES - * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND - * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT - * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, - * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING - * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR - * OTHER DEALINGS IN THE SOFTWARE. - * - * ----------------------------------------------------------------------- */ - -/* - * Modified MBR code used on an ISO image in hybrid mode. - * - * This doesn't follow the El Torito spec at all -- it is just a stub - * loader of a hard-coded offset, but that's good enough to load - * ISOLINUX. - */ - -#include "adjust.h" - - .code16 - .text - -HYBRID_MAGIC = 0x7078c0fb -isolinux_hybrid_signature = 0x7c00+64 -isolinux_start_hybrid = 0x7c00+64+4 - - .globl bootsec -/* Important: the top 6 words on the stack are passed to isolinux.bin */ -stack = 0x7c00 -partoffset = (stack-8) -driveno = (stack-14) -heads = (stack-16) -sectors = (stack-18) -ebios_flag = (stack-20) -secpercyl = (stack-24) - -BIOS_kbdflags = 0x417 -BIOS_page = 0x462 - - /* gas/ld has issues with doing this as absolute addresses... */ - .section ".bootsec", "a", @nobits - .globl bootsec -bootsec: - .space 512 - - .text - .globl _start -_start: - - cli - xorw %bp, %bp - movw %bp, %ss - movw $stack, %sp - sti - cld - - /* Check to see if we have a partition table entry */ - xorl %ebx, %ebx - xorl %ecx, %ecx -#ifdef PARTITION_SUPPORT - andw %si, %si /* %si == 0 -> no partition data */ - jz 1f - testb $0x7f, (%si) /* Invalid active flag field? */ - jnz 1f - cmpb %cl, 4(%si) /* Partition type zero == invalid? */ - je 1f - cmpl $0x58504721, %eax /* !GPT signature in EAX? */ - jne 2f - cmpb $0xed, 4(%si) /* EFI partition type? */ - jne 2f - - /* We have GPT partition information */ - movl (32+20)(%si), %ecx - movl (36+20)(%si), %ebx - jmp 1f - - /* We have non-GPT partition information */ -2: - movl 8(%si), %ecx -#endif -1: - /* We have no partition information */ - pushl %ebx /* -4: partoffset_hi */ - pushl %ecx /* -8: partoffset_lo */ - pushw %es /* -10: es:di -> $PnP header */ - pushw %di /* -12: es:di -> $PnP header */ - - movw %bp, %ds - movw %bp, %es - - ADJUST_DRIVE - pushw %dx /* -14: dl -> drive number */ - - /* Copy down to 0:0x600 */ - movw $0x7c00, %si - movw $_start, %di - movw $(512/2), %cx - rep; movsw - - ljmpw $0, $next -next: - - /* Check to see if we have EBIOS */ - pushw %dx /* drive number */ - movb $0x41, %ah /* %al == 0 already */ - movw $0x55aa, %bx - xorw %cx, %cx - xorb %dh, %dh - stc - int $0x13 - jc 1f - cmpw $0xaa55, %bx - jne 1f - andw $1,%cx /* Bit 0 = fixed disk subset */ - jz 1f - - /* We have EBIOS; patch in the following code at - read_sector_cbios: movb $0x42, %ah ; jmp read_common */ - movl $0xeb42b4+((read_common-read_sector_cbios-4) << 24), \ - (read_sector_cbios) - jmp 1f -1: - popw %dx - pushw %cx /* EBIOS flag */ - - /* Get (C)HS geometry */ - movb $0x08, %ah - int $0x13 - andw $0x3f, %cx /* Sector count */ - popw %bx /* EBIOS flag */ - pushw %cx /* -16: Save sectors on the stack */ - movzbw %dh, %ax /* dh = max head */ - incw %ax /* From 0-based max to count */ - pushw %ax /* -18: Save heads on the stack */ - mulw %cx /* Heads*sectors -> sectors per cylinder */ - - pushw %bx /* -20: EBIOS flag */ - - /* Save sectors/cylinder on the stack */ - pushw %dx /* -22: High word */ - pushw %ax /* -24: Low word */ - - /* - * Load sectors. We do this one at a time mostly to avoid - * pitfalls and to share code with the stock MBR code. - */ - movw $0x7c00, %bx - movw $4, %cx /* Sector count */ - movl (lba_offset), %eax - -2: - call read_sector - jc disk_error - incl %eax - addb $(512 >> 8), %bh - loopw 2b - - /* - * Okay, that actually worked... update the stack pointer - * and jump into isolinux.bin... - */ - cmpl $HYBRID_MAGIC,(isolinux_hybrid_signature) - jne bad_signature - - cli - movw $ebios_flag, %sp - - /* - * Use a ljmpw here to work around a bug in some unknown version - * of gas or ld when it comes to jumping to an absolute symbol... - * - * Look more closely into it if we ever are short on space. - */ - ljmpw $0, $isolinux_start_hybrid - -bad_signature: - call error - .ascii "isolinux.bin missing or corrupt.\r\n" - -/* - * read_sector: read a single sector pointed to by %eax to %es:%bx. - * CF is set on error. All registers saved. - */ -read_sector: - pushal - xorl %edx, %edx - addl (partoffset), %eax - adcl (partoffset+4), %edx - pushl %edx /* MSW of LBA */ - pushl %eax /* LSW of LBA */ - pushw %es /* Buffer segment */ - pushw %bx /* Buffer offset */ - pushw $1 /* Sector count */ - pushw $16 /* Size of packet */ - movw %sp, %si - - /* This chunk is skipped if we have ebios */ - /* Do not clobber %eax before this chunk! */ - /* This also relies on %bx and %edx as set up above. */ -read_sector_cbios: - divl (secpercyl) - shlb $6, %ah - movb %ah, %cl - movb %al, %ch - xchgw %dx, %ax - divb (sectors) - movb %al, %dh - orb %ah, %cl - incw %cx /* Sectors are 1-based */ - movw $0x0201, %ax - -read_common: - movb (driveno), %dl - int $0x13 - leaw 16(%si), %sp /* Drop DAPA */ - popal - ret - -disk_error: - call error - .ascii "Operating system load error.\r\n" - -/* - * Print error messages. This is invoked with "call", with the - * error message at the return address. - */ -error: - popw %si -2: - lodsb - movb $0x0e, %ah - movb (BIOS_page), %bh - movb $0x07, %bl - int $0x10 /* May destroy %bp */ - cmpb $10, %al /* Newline? */ - jne 2b - - int $0x18 /* Boot failure */ -die: - hlt - jmp die - - /* Address of pointer to isolinux.bin */ -lba_offset = _start+432 |