diff options
Diffstat (limited to 'sys/boot/i386/libi386/crt/bootsect/start_bootsect.S')
| -rw-r--r-- | sys/boot/i386/libi386/crt/bootsect/start_bootsect.S | 540 |
1 files changed, 0 insertions, 540 deletions
diff --git a/sys/boot/i386/libi386/crt/bootsect/start_bootsect.S b/sys/boot/i386/libi386/crt/bootsect/start_bootsect.S deleted file mode 100644 index 438ae69..0000000 --- a/sys/boot/i386/libi386/crt/bootsect/start_bootsect.S +++ /dev/null @@ -1,540 +0,0 @@ -/* $NetBSD: start_bootsect.S,v 1.3 1998/02/19 14:15:38 drochner Exp $ */ - -/* BIOS bootsector startup - parts from netbsd:sys/arch/i386/boot/start.S - and freebsd:sys/i386/boot/biosboot/boot2.S - */ - -/* - * Ported to boot 386BSD by Julian Elischer (julian@tfs.com) Sept 1992 - * - * Mach Operating System - * Copyright (c) 1992, 1991 Carnegie Mellon University - * All Rights Reserved. - * - * Permission to use, copy, modify and distribute this software and its - * documentation is hereby granted, provided that both the copyright - * notice and this permission notice appear in all copies of the - * software, derivative works or modified versions, and any portions - * thereof, and that both notices appear in supporting documentation. - * - * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" - * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR - * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. - * - * Carnegie Mellon requests users of this software to return to - * - * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU - * School of Computer Science - * Carnegie Mellon University - * Pittsburgh PA 15213-3890 - * - * any improvements or extensions that they make and grant Carnegie Mellon - * the rights to redistribute these changes. - */ - -/* - Copyright 1988, 1989, 1990, 1991, 1992 - by Intel Corporation, Santa Clara, California. - - All Rights Reserved - -Permission to use, copy, modify, and distribute this software and -its documentation for any purpose and without fee is hereby -granted, provided that the above copyright notice appears in all -copies and that both the copyright notice and this permission notice -appear in supporting documentation, and that the name of Intel -not be used in advertising or publicity pertaining to distribution -of the software without specific, written prior permission. - -INTEL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE -INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, -IN NO EVENT SHALL INTEL BE LIABLE FOR ANY SPECIAL, INDIRECT, OR -CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM -LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT, -NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION -WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. -*/ - -#include <machine/asm.h> -#define addr32 .byte 0x67 -#define data32 .byte 0x66 -/* #include <machine/disklabel.h> */ - -#include "bbinfo.h" - -BOOTSEG = 0x0100 # boot will be loaded here (below 640K) -BOOTSTACK = 0xfffc # boot stack -LOADSZ = PRIM_LOADSZ # size of first loaded chunk - -SIGNATURE = 0xaa55 -PARTSTART = 0x1be # starting address of partition table -NUMPART = 4 # number of partitions in partition table -PARTSZ = 16 # sizeof(struct dos_partition) -BSDPART = 0xA5 -BOOTABLE = 0x80 # value of dp_flag, means bootable partition - - .text -_boot1: -ENTRY(start) - # start (aka boot1) is loaded at 0x0:0x7c00 but we want 0x7c0:0 - # ljmp to the next instruction to adjust %cs - data32 - ljmp $0x7c0, $start1 - -start1: - # set up %ds - movl %cs, %ax - movl %ax, %ds - - # temporary stack while we locate boot2 - # set up %ss and %esp - data32 - movl $BOOTSEG, %eax - movl %ax, %ss - data32 - movl $BOOTSTACK, %esp - - /*** set up %es, (where we will load boot2 to) ***/ - movl %ax, %es - - # bootstrap passes us drive number in %dl - cmpb $0x80, %dl - data32 - jae hd - -fd: -# reset the disk system - movb $0x00, %ah - int $0x13 - data32 - movl $0x0001, %ecx # cyl 0, sector 1 - movb $0x00, %dh # head - # XXX Override the drive number. - movb $0x00, %dl - data32 - jmp load - -hd: /**** load sector 0 (DOSBBSECTOR) into the BOOTSEG ****/ - data32 - movl $0x0201, %eax - xorl %ebx, %ebx # %bx = 0 - data32 - movl $0x0001, %ecx - data32 - andl $0xff, %edx - /*mov $0x0080, %edx*/ - int $0x13 - data32 - jb read_error - - /***# find the first BSD partition *****/ - data32 - movl $PARTSTART, %ebx - data32 - movl $NUMPART, %ecx -again: - addr32 - movb %es:4(%ebx), %al /* dp_typ */ - cmpb $BSDPART, %al - data32 - je found - data32 - addl $PARTSZ, %ebx - data32 - loop again - - /* didn't find either NetBSD or 386BSD partitions */ - data32 - movl $enoboot, %esi - data32 - jmp err_stop - - -/* -# BIOS call "INT 0x13 Function 0x2" to read sectors from disk into memory -# Call with %ah = 0x2 -# %al = number of sectors -# %ch = cylinder -# %cl = sector -# %dh = head -# %dl = drive (0x80 for hard disk, 0x0 for floppy disk) -# %es:%bx = segment:offset of buffer -# Return: -# %al = 0x0 on success; err code on failure -*/ - -found: - addr32 - movb %es:1(%ebx), %dh /* head: dp_sdh */ - addr32 - movl %es:2(%ebx), %ecx /*sect, cyl: dp_ssect + (dp_scyl << 8)*/ - -load: - movb $0x2, %ah /* function 2 */ - movb $LOADSZ, %al /* number of blocks */ - xorl %ebx, %ebx /* %bx = 0, put it at 0 in the BOOTSEG */ - int $0x13 - data32 - jb read_error - - # ljmp to the second stage boot loader (boot2). - # After ljmp, %cs is BOOTSEG and boot1 (512 bytes) will be used - # for stack space while we load boot3. - - data32 - ljmp $BOOTSEG, $CNAME(boot2) - -# -# read_error -# - -read_error: - data32 - movl $eread, %esi -err_stop: - data32 - call message - data32 - jmp stop - -# -# message: write the error message in %ds:%esi to console -# - -message: -/* -# BIOS call "INT 10H Function 0Eh" to write character to console -# Call with %ah = 0x0e -# %al = character -# %bh = page -# %bl = foreground color -*/ - data32 - pushl %eax - data32 - pushl %ebx - data32 - pushl %edx - -nextb: - cld - lodsb # load a byte into %al - testb %al, %al - data32 - jz done - - movb $0x0e, %ah - data32 - movl $0x0001, %ebx - int $0x10 - - data32 - jmp nextb - -done: - data32 - popl %edx - data32 - popl %ebx - data32 - popl %eax - data32 - ret - -_ourseg: - .long 0 - -/************************************************************************** -GLOBAL DESCRIPTOR TABLE -**************************************************************************/ - .align 4 -gdt: /* 0x0 */ - .word 0, 0 - .byte 0, 0x00, 0x00, 0 - -/* additional dummy for Linux support (?) */ /* 0x8 */ - .word 0, 0 - .byte 0, 0x00, 0x00, 0 - - /* kernel code segment */ - .globl flatcodeseg -flatcodeseg = . - gdt /* 0x10 */ - .word 0xffff, 0 - .byte 0, 0x9f, 0xcf, 0 - - /* kernel data segment */ - .globl flatdataseg -flatdataseg = . - gdt /* 0x18 */ - .word 0xffff, 0 - .byte 0, 0x93, 0xcf, 0 - - /* boot code segment, will be patched */ -bootcodeseg = . - gdt /* 0x20 */ - .word 0xffff, 0 - .byte 0, 0x9e, 0x40, 0 - - /* boot data segment, will be patched */ -bootdataseg = . - gdt /* 0x28 */ - .word 0xffff, 0 - .byte 0, 0x92, 0x0f, 0 - - /* 16 bit real mode, will be patched */ -bootrealseg = . - gdt /* 0x30 */ - .word 0xffff, 0 - .byte 0, 0x9e, 0x00, 0 -gdtlen = . - gdt - - .align 4 -gdtarg: - .word gdtlen-1 /* limit */ - .long 0 /* addr, will be inserted */ - -_boot2: - data32 - xorl %eax, %eax - movl %cs, %ax - movl %ax, %ds - movl %ax, %es - addr32 - data32 - movl %eax, CNAME(ourseg) - data32 - shll $4, %eax - - /* fix up GDT entries for bootstrap */ -#define FIXUP(gdt_index) \ - addr32; \ - movl %eax, gdt+gdt_index+2; /* actually movw %ax */ \ - addr32; \ - movb %bl, gdt+gdt_index+4 - - data32 - shldl $16, %eax, %ebx - - FIXUP(bootcodeseg) - FIXUP(bootrealseg) - FIXUP(bootdataseg) - - /* fix up GDT pointer */ - data32 - addl $gdt, %eax - addr32 - data32 - movl %eax, gdtarg+2 - - /* change to protected mode */ - data32 - call CNAME(real_to_prot) - - /* move the stack over the top of boot1 while we load */ - movl $_ourseg - 4, %eax - movl %eax, %esp - - movzbl %dl, %edx /* discard head (%dh) and random high bits */ - pushl %edx - call CNAME(bootsectmain) - - /* Go to internal stack */ - movl $CNAME(stacktop), %eax - movl %eax, %esp - call CNAME(main) - - -ENTRY(exit) -stop: - cli - hlt - -eread: .asciz "Read error\r\n" -enoboot: .asciz "No bootable partition\r\n" -endofcode: -/* throw in a partition in case we are block0 as well */ -/* flag, head, sec, cyl, typ, ehead, esect, ecyl, start, len */ - . = CNAME(boot1) + PARTSTART - .byte 0x0,0,0,0,0,0,0,0 - .long 0,0 - .byte 0x0,0,0,0,0,0,0,0 - .long 0,0 - .byte 0x0,0,0,0,0,0,0,0 - .long 0,0 - .byte BOOTABLE,0,1,0,BSDPART,255,255,255 - .long 0,50000 -/* the last 2 bytes in the sector 0 contain the signature */ - . = CNAME(boot1) + 0x1fe - .short SIGNATURE - . = CNAME(boot1) + 0x200 - .globl _disklabel -_disklabel: - . = CNAME(boot1) + 0x400 - - -CR0_PE = 0x1 -/* - * real_to_prot() - * transfer from real mode to protected mode. - */ -ENTRY(real_to_prot) - # guarantee that interrupt is disabled when in prot mode - cli - - # load the gdtr - addr32 - data32 - lgdt gdtarg - - # set the PE bit of CR0 - movl %cr0, %eax - - data32 - orl $CR0_PE, %eax - movl %eax, %cr0 - - # make intrasegment jump to flush the processor pipeline and - # reload CS register - data32 - ljmp $bootcodeseg, $xprot - -xprot: - # we are in USE32 mode now - # set up the protected mode segment registers : DS, SS, ES - movl $bootdataseg, %eax - movl %ax, %ds - movl %ax, %ss - movl %ax, %es - - ret - -/* - * prot_to_real() - * transfer from protected mode to real mode - */ -ENTRY(prot_to_real) - # set up a dummy stack frame for the second seg change. - # Adjust the intersegment jump instruction following - # the clearing of protected mode bit. - # This is self-modifying code, but we need a writable - # code segment, and an intersegment return does not give us that. - - movl _ourseg, %eax - movw %ax, xreal-2 - - # Change to use16 mode. - ljmp $bootrealseg, $x16 - -x16: - # clear the PE bit of CR0 - movl %cr0, %eax - data32 - andl $~CR0_PE, %eax - movl %eax, %cr0 - # Here we have an 16 bits intersegment jump. - .byte 0xea - .word xreal - .word 0 - -xreal: - # we are in real mode now - # set up the real mode segment registers : DS, SS, ES - movl %cs, %ax - movl %ax, %ds - movl %ax, %ss - movl %ax, %es - - sti - data32 - ret - -/* - * pbzero(dst, cnt) - * where dst is a physical address and cnt is the length - */ -ENTRY(pbzero) - pushl %ebp - movl %esp, %ebp - pushl %es - pushl %edi - - cld - - # set %es to point at the flat segment - movl $flatdataseg, %eax - movl %ax, %es - - movl 8(%ebp), %edi # destination - movl 12(%ebp), %ecx # count - xorl %eax, %eax # value - - rep - stosb - - popl %edi - popl %es - popl %ebp - ret - -/* - * vpbcopy(src, dst, cnt) - * where src is a virtual address and dst is a physical address - */ -ENTRY(vpbcopy) - pushl %ebp - movl %esp, %ebp - pushl %es - pushl %esi - pushl %edi - - cld - - # set %es to point at the flat segment - movl $flatdataseg, %eax - movl %ax, %es - - movl 8(%ebp), %esi # source - movl 12(%ebp), %edi # destination - movl 16(%ebp), %ecx # count - - rep - movsb - - popl %edi - popl %esi - popl %es - popl %ebp - ret - -/* - * pvbcopy(src, dst, cnt) - * where src is a physical address and dst is a virtual address - */ -ENTRY(pvbcopy) - pushl %ebp - movl %esp, %ebp - pushl %ds - pushl %esi - pushl %edi - - cld - - # set %ds to point at the flat segment - movl $flatdataseg, %eax - movl %ax, %ds - - movl 8(%ebp), %esi # source - movl 12(%ebp), %edi # destination - movl 16(%ebp), %ecx # count - - rep - movsb - - popl %edi - popl %esi - popl %ds - popl %ebp - ret - -ENTRY(vtophys) - movl _ourseg, %eax - shll $4, %eax - addl 4(%esp), %eax - ret |
