diff options
author | jlemon <jlemon@FreeBSD.org> | 2000-07-17 17:06:04 +0000 |
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committer | jlemon <jlemon@FreeBSD.org> | 2000-07-17 17:06:04 +0000 |
commit | 21066c4e6325eed94474ab26509d7d8e72a4cd42 (patch) | |
tree | 36455798040721fb8a0f6d19258e00dbb063ce0d /sys/boot | |
parent | 59ad463b6cb30b2828ca1c035845c8b43c8a3e1b (diff) | |
download | FreeBSD-src-21066c4e6325eed94474ab26509d7d8e72a4cd42.zip FreeBSD-src-21066c4e6325eed94474ab26509d7d8e72a4cd42.tar.gz |
This is `liloboot', which creates a file which can be treated like a
Linux kernel image, and is designed to be dropped into a Linux system
and booted via LILO. Once booted, the user is greeted by the FreeBSD
loader. This still isn't quite complete, as the the root= specification
from LILO isn't currently passed to the loader yet.
Diffstat (limited to 'sys/boot')
-rw-r--r-- | sys/boot/i386/liloldr/Makefile | 51 | ||||
-rw-r--r-- | sys/boot/i386/liloldr/lilobsect.s | 41 | ||||
-rw-r--r-- | sys/boot/i386/liloldr/liloldr.s | 280 |
3 files changed, 372 insertions, 0 deletions
diff --git a/sys/boot/i386/liloldr/Makefile b/sys/boot/i386/liloldr/Makefile new file mode 100644 index 0000000..4f44a94 --- /dev/null +++ b/sys/boot/i386/liloldr/Makefile @@ -0,0 +1,51 @@ +# $FreeBSD$ + +ORG= 0x0 + +LDR= liloldr +BSECT= lilobsect +BOOT= liloboot +PROG= ${BOOT} +MAN8= ${BOOT}.8 +STRIP= +BINDIR?= /boot + +.if exists(${.OBJDIR}/../loader) +LOADER= ${.OBJDIR}/../loader/loader +.else +LOADER= ${.CURDIR}/../loader/loader +.endif + +LOADER_SIZE != wc -c ${LOADER} | awk '{print int(($$1 + 15) / 16)}' +AFLAGS= --defsym LOADER_SIZE=${LOADER_SIZE} + +${BOOT}: ${BSECT} ${LDR} ${LOADER} + cat ${BSECT} ${LDR} ${LOADER} > ${.TARGET}.tmp + dd if=${.TARGET}.tmp of=${.TARGET} obs=2k conv=osync + rm ${.TARGET}.tmp + +${LDR}: ${LDR}.o +.if ${OBJFORMAT} == aout + ${LD} -nostdlib -N -s -T ${ORG} -o ${LDR}.out ${LDR}.o + dd if=${LDR}.out of=${.TARGET} ibs=32 skip=1 +.else + ${LD} -N -e start -Ttext ${ORG} -o ${LDR}.out ${LDR}.o + objcopy -S -O binary ${LDR}.out ${.TARGET} +.endif + +${BSECT}: ${BSECT}.o +.if ${OBJFORMAT} == aout + ${LD} -nostdlib -N -s -T ${ORG} -o ${BSECT}.out ${BSECT}.o + dd if=${BSECT}.out of=${.TARGET} ibs=32 skip=1 +.else + ${LD} -N -e start -Ttext ${ORG} -o ${BSECT}.out ${BSECT}.o + objcopy -S -O binary ${BSECT}.out ${.TARGET} +.endif + + +${BSECT}.o: ${BSECT}.s ${LOADER} + +CLEANFILES+= ${LDR} ${LDR}.out ${LDR}.o \ + ${BSECT} ${BSECT}.out ${BSECT}.o ${BOOT}.tmp + +.include <bsd.prog.mk> diff --git a/sys/boot/i386/liloldr/lilobsect.s b/sys/boot/i386/liloldr/lilobsect.s new file mode 100644 index 0000000..0c81f5f --- /dev/null +++ b/sys/boot/i386/liloldr/lilobsect.s @@ -0,0 +1,41 @@ +# +# Copyright (c) 2000 Jonathan Lemon +# All rights reserved. +# +# Redistribution and use in source and binary forms are freely +# permitted provided that the above copyright notice and this +# paragraph and the following disclaimer are duplicated in all +# such forms. +# +# This software is provided "AS IS" and without any express or +# implied warranties, including, without limitation, the implied +# warranties of merchantability and fitness for a particular +# purpose. +# +# $FreeBSD$ + +# +# LILO constants +# + .set SETUP_OFF,497 # offset of setup table + .set SETUP_SECTORS,4 # historical + + .globl start + .org 0x0, 0x0 +# +# Create an empty bootblock, but fill in the setup table. +# +bootsect: + .org SETUP_OFF,0x00 +# +# bootblock setup for LILO +# + .byte SETUP_SECTORS # size of setup code in sectors + .word 0x00 # read only root + .word LOADER_SIZE # size of kernel in 16B units + .word 0x00 # not used (swap dev?) + .word 0x00 # ram disk size in KB + .word 0xffff # video mode (80x25) + .byte 0x00 # root dev major number + .byte 0x00 # root dev minor number + .word 0xaa55 # Magic number diff --git a/sys/boot/i386/liloldr/liloldr.s b/sys/boot/i386/liloldr/liloldr.s new file mode 100644 index 0000000..3aaa197 --- /dev/null +++ b/sys/boot/i386/liloldr/liloldr.s @@ -0,0 +1,280 @@ +# +# Copyright (c) 2000 Jonathan Lemon <jlemon@FreeBSD.org> +# Copyright (c) 2000 John Baldwin +# All rights reserved. +# +# Redistribution and use in source and binary forms are freely +# permitted provided that the above copyright notice and this +# paragraph and the following disclaimer are duplicated in all +# such forms. +# +# This software is provided "AS IS" and without any express or +# implied warranties, including, without limitation, the implied +# warranties of merchantability and fitness for a particular +# purpose. +# +# $FreeBSD$ + +# +# This simple program is a preloader for the normal boot3 loader. It is +# simply prepended to the beginning of a fully built and btxld'd loader. +# It then copies the loader to the address boot2 normally loads it, emulates +# the boot[12] environment (protected mode, a bootinfo struct, etc.), and +# then jumps to the start of btxldr to start the boot process. This method +# allows a stock /boot/loader to be booted from LILO. +# + +# +# Memory locations. +# + .set MEM_PAGE_SIZE,0x1000 # memory page size, 4k + .set MEM_ARG,0x900 # Arguments at start + .set MEM_ARG_BTX,0xa100 # Where we move them to so the + # BTX client can see them + .set MEM_ARG_SIZE,0x18 # Size of the arguments + .set MEM_BTX_ADDRESS,0x9000 # where BTX lives + .set MEM_BTX_ENTRY,0x9010 # where BTX starts to execute + .set MEM_BTX_OFFSET,MEM_PAGE_SIZE # offset of BTX in the loader + .set MEM_BTX_CLIENT,0xa000 # where BTX clients live +# +# a.out header fields +# + .set AOUT_TEXT,0x04 # text segment size + .set AOUT_DATA,0x08 # data segment size + .set AOUT_BSS,0x0c # zero'd BSS size + .set AOUT_SYMBOLS,0x10 # symbol table + .set AOUT_ENTRY,0x14 # entry point + .set AOUT_HEADER,MEM_PAGE_SIZE # size of the a.out header +# +# Flags for kargs->bootflags +# + .set KARGS_FLAGS_LILO,0x4 # flag to indicate booting from + # LILO loader +# +# Segment selectors. +# + .set SEL_SDATA,0x8 # Supervisor data + .set SEL_RDATA,0x10 # Real mode data + .set SEL_SCODE,0x18 # PM-32 code + .set SEL_SCODE16,0x20 # PM-16 code +# +# BTX constants +# + .set INT_SYS,0x30 # BTX syscall interrupt +# +# LILO constants +# + .set SETUP_OFF,497 # offset of setup table + .set SETUP_SECTORS,4 # historical + .set SEG_LOADER,0x1000 # segment for loader + .set SEG_BSECT,0x9000 # segment for bootsector + .set SEG_SETUP,0x9020 # segment for setup + .set LDR_BASE,0x10000 # where LILO puts loader + .set SETUP_BASE,0x90200 # base address for us + .set ROOT_DEV,0x901FC +# +# We expect to be loaded by LILO at 0x90200, and the loader at LDR_BASE +# %cs upon entry == SEG_SETUP == 0x9020 +# + .code16 + .globl start + .org 0x0, 0x0 +# +# BTX program loader for LILO booting +# +start: jmp code_start + + .ascii "HdrS" # signature + .word 0x0201 # version + .word 0x00,0x00,0x00 # LOADLIN hacks + .word welcome_msg + .byte 0x00 # loader type (LILO) + .byte 0x00 # load kernel high (NO) + .word 0x00 # LOADLIN hacks + .long SEG_LOADER # load address + .long 0x00 # ramdisk image + .long 0x00 # ramdisk size + .word 0x00,0x00 # bzImage hacks + .word 0x00 # heap end pointer + +code_start: cld # string ops inc + movw $SEG_BSECT, %ax # use bootsector area + movw %ax, %ss # for the + movw $0x1E0, %sp # stack + movw %cs, %ax # inherit code segment + movw %ax, %ds # setup the + movw %ax, %es # data segments + movw $welcome_msg, %si # %ds:(%si) -> welcome message + callw putstr # display the welcome message +# +# Turn on the A20 address line +# + callw seta20 # Turn A20 on +# +# Dealing with segments is a pain, so move into protected mode immediately. +# + movw $relocate_msg, %si # Display the + callw putstr # relocation message + lgdt gdtdesc # setup our own gdt + cli # turn off interrupts + movl %cr0, %eax # Turn on + orb $0x1, %al # protected + movl %eax, %cr0 # mode + ljmp $SEL_SCODE,$pm_start # long jump to clear the + # instruction pre-fetch queue + .code32 +pm_start: movw $SEL_SDATA, %ax # Initialize + movw %ax, %ds # %ds and + movw %ax, %es # %es to a flat selector + movl LDR_BASE+AOUT_ENTRY, %edi # %edi is the destination + movl $LDR_BASE+AOUT_HEADER, %esi # %esi is + # the start of the text + # segment + movl LDR_BASE+AOUT_TEXT, %ecx # %ecx = length of the text + # segment + rep # Relocate the + movsb # text segment + addl $(MEM_PAGE_SIZE - 1), %edi # pad %edi out to a new page + andl $~(MEM_PAGE_SIZE - 1), %edi # for the data segment + movl LDR_BASE+AOUT_DATA, %ecx # size of the data segment + rep # Relocate the + movsb # data segment + movl LDR_BASE+AOUT_BSS, %ecx # size of the bss + xorl %eax, %eax # zero %eax + addb $3, %cl # round %ecx up to + shrl $2, %ecx # a multiple of 4 + rep # zero the + stosl # bss + movl LDR_BASE+AOUT_ENTRY, %esi # %esi -> relocated loader + addl $MEM_BTX_OFFSET, %esi # %esi -> BTX in the loader + movl $MEM_BTX_ADDRESS, %edi # %edi -> where BTX needs to go + movzwl 0xa(%esi), %ecx # %ecx -> length of BTX + rep # Relocate + movsb # BTX +# +# Copy the BTX client to MEM_BTX_CLIENT +# + movl $MEM_BTX_CLIENT, %edi # Prepare to relocate + movl $SETUP_BASE+btx_client, %esi # the simple btx client + movl $(btx_client_end-btx_client), %ecx # length of btx client + rep # Relocate the + movsb # simple BTX client +# +# Setup the boot[12] args for the BTX client +# + movl $MEM_ARG_BTX, %ebx # %ebx -> boot args + movl %ebx, %edi # Destination + movl $(MEM_ARG_SIZE/4), %ecx # Size of the arguments in longs + xorl %eax, %eax # zero %eax + rep # Clear the arguments + stosl # to zero + movw $KARGS_FLAGS_LILO, 0x8(%ebx) # set kargs->bootflags + movw ROOT_DEV, %ax + movw %ax, 0x04(%ebx) +# +# Save the entry point so the client can get to it later on +# + movl LDR_BASE+AOUT_ENTRY, %eax # load the entry point + stosl # add it to the end of the + # arguments +# +# setup is done, return +# + ljmp $SEL_SCODE16,$pm_16 # Jump to 16-bit PM + .code16 +pm_16: movw $SEL_RDATA, %ax # Initialize + movw %ax, %ds # %ds and + movw %ax, %es # %es to a real mode selector + movl %cr0, %eax # Turn off + andb $~0x1, %al # protected + movl %eax, %cr0 # mode + ljmp $SEG_SETUP,$pm_end # Long jump to clear the + # instruction pre-fetch queue +pm_end: sti # Turn interrupts back on now +# +# Restore real mode environment +# + movw %cs, %ax # inherit code segment + movw %ax, %ds # setup the + movw %ax, %es # data segments +# +# Now we just start up BTX and let it do the rest +# + movw $jump_message, %si # Display the + callw putstr # jump message + ljmp $0,$MEM_BTX_ENTRY # Jump to the BTX entry point +# +# Display a null-terminated string +# +putstr: lodsb # load %al from %ds:(%si) + testb %al,%al # stop at null + jnz putc # if the char != null, output it + retw # return when null is hit +putc: movw $0x7,%bx # attribute for output + movb $0xe,%ah # BIOS: put_char + int $0x10 # call BIOS, print char in %al + jmp putstr # keep looping + +# +# Enable A20 +# +seta20: cli # Disable interrupts +seta20.1: inb $0x64,%al # Get status + testb $0x2,%al # Busy? + jnz seta20.1 # Yes + movb $0xd1,%al # Command: Write + outb %al,$0x64 # output port +seta20.2: inb $0x64,%al # Get status + testb $0x2,%al # Busy? + jnz seta20.2 # Yes + movb $0xdf,%al # Enable + outb %al,$0x60 # A20 + sti # Enable interrupts + retw # To caller + +# +# BTX client to start btxldr +# + .code32 +btx_client: movl $(MEM_ARG_BTX-MEM_BTX_CLIENT+MEM_ARG_SIZE-4), %esi + # %ds:(%esi) -> end + # of boot[12] args + movl $(MEM_ARG_SIZE/4), %ecx # Number of words to push + std # Go backwards +push_arg: lodsl # Read argument + pushl %eax # Push it onto the stack + loop push_arg # Push all of the arguments + cld # In case anyone depends on this + pushl MEM_ARG_BTX-MEM_BTX_CLIENT+MEM_ARG_SIZE # Entry point of + # the loader + pushl %eax # Emulate a near call + movl $0x1, %eax # 'exec' system call + int $INT_SYS # BTX system call +btx_client_end: + .code16 + + .p2align 4 +# +# Global descriptor table. +# +gdt: .word 0x0,0x0,0x0,0x0 # Null entry + .word 0xffff,0x0,0x9200,0xcf # SEL_SDATA + .word 0xffff,0x0200,0x9209,0x0f # SEL_RDATA + .word 0xffff,0x0200,0x9a09,0x4f # SEL_SCODE (32-bit) + .word 0xffff,0x0200,0x9a09,0x0f # SEL_SCODE16 (16-bit) +gdt.1: +# +# Pseudo-descriptors. +# +gdtdesc: .word gdt.1-gdt-1 # Limit + .long gdt+SETUP_BASE # Base + +welcome_msg: .asciz "LILO Loader 1.00\r\n\n" +bootinfo_msg: .asciz "Building the boot loader arguments\r\n" +relocate_msg: .asciz "Relocating the loader and the BTX\r\n" +jump_message: .asciz "Starting the BTX loader\r\n" +# +# pad out to setup sectors. +# + .org SETUP_SECTORS*512,0x00 +end: |