diff options
Diffstat (limited to 'sys/boot/i386/pxeldr/pxeldr.s')
| -rw-r--r-- | sys/boot/i386/pxeldr/pxeldr.s | 287 |
1 files changed, 0 insertions, 287 deletions
diff --git a/sys/boot/i386/pxeldr/pxeldr.s b/sys/boot/i386/pxeldr/pxeldr.s deleted file mode 100644 index fa93c9c..0000000 --- a/sys/boot/i386/pxeldr/pxeldr.s +++ /dev/null @@ -1,287 +0,0 @@ -# -# 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 over the network via PXE w/o having to write a -# separate PXE-aware client just to load the loader. -# - -# -# 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 - .set MEM_BIOS_KEYBOARD,0x496 # BDA byte with keyboard bit -# -# 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_PXE,0x2 # flag to indicate booting from - # PXE loader -# -# Boot howto bits -# - .set RB_SERIAL,0x1000 # serial console -# -# 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 -# -# Bit in MEM_BIOS_KEYBOARD that is set if an enhanced keyboard is present -# - .set KEYBOARD_BIT,0x10 -# -# We expect to be loaded by the BIOS at 0x7c00 (standard boot loader entry -# point) -# - .code16 - .globl start - .org 0x0, 0x0 -# -# BTX program loader for PXE network booting -# -start: cld # string ops inc - xorw %ax, %ax # zero %ax - movw %ax, %ss # setup the - movw $start, %sp # stack - movw %es, %cx # save PXENV+ segment - movw %ax, %ds # setup the - movw %ax, %es # data segments - andl $0xffff, %ecx # clear upper words - andl $0xffff, %ebx # of %ebx and %ecx - shll $4, %ecx # calculate the offset of - addl %ebx, %ecx # the PXENV+ struct and - pushl %ecx # save it on the stack - movw $welcome_msg, %si # %ds:(%si) -> welcome message - callw putstr # display the welcome message -# -# Setup the arguments that the loader is expecting from boot[12] -# - movw $bootinfo_msg, %si # %ds:(%si) -> boot args message - callw putstr # display the message - movw $MEM_ARG, %bx # %ds:(%bx) -> boot args - movw %bx, %di # %es:(%di) -> boot args - xorl %eax, %eax # zero %eax - movw $(MEM_ARG_SIZE/4), %cx # Size of arguments in 32-bit - # dwords - rep # Clear the arguments - stosl # to zero - orb $KARGS_FLAGS_PXE, 0x8(%bx) # kargs->bootflags |= - # KARGS_FLAGS_PXE - popl 0xc(%bx) # kargs->pxeinfo = *PXENV+ -ifdef(`ALWAYS_SERIAL',` -# -# set the RBX_SERIAL bit in the howto byte. - orl $RB_SERIAL, (%bx) # enable serial console -') -ifdef(`PROBE_KEYBOARD',` -# -# Look at the BIOS data area to see if we have an enhanced keyboard. If not, -# set the RBX_SERIAL bit in the howto byte. - testb $KEYBOARD_BIT, MEM_BIOS_KEYBOARD # keyboard present? - jnz keyb # yes, so skip - orl $RB_SERIAL, (%bx) # enable serial console -keyb: -') -# -# Turn on the A20 address line -# - callw seta20 # Turn A20 on -# -# Relocate the loader and BTX using a very lazy protected mode -# - movw $relocate_msg, %si # Display the - callw putstr # relocation message - movl end+AOUT_ENTRY, %edi # %edi is the destination - movl $(end+AOUT_HEADER), %esi # %esi is - # the start of the text - # segment - movl end+AOUT_TEXT, %ecx # %ecx = length of the text - # segment - 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 - 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 end+AOUT_DATA, %ecx # size of the data segment - rep # Relocate the - movsb # data segment - movl end+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 end+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 - 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 $0,$pm_end # Long jump to clear the - # instruction pre-fetch queue -pm_end: sti # Turn interrupts back on now -# -# Copy the BTX client to MEM_BTX_CLIENT -# - xorw %ax, %ax # zero %ax and set - movw %ax, %ds # %ds and %es - movw %ax, %es # to segment 0 - movw $MEM_BTX_CLIENT, %di # Prepare to relocate - movw $btx_client, %si # the simple btx client - movw $(btx_client_end-btx_client), %cx # length of btx client - rep # Relocate the - movsb # simple BTX client -# -# Copy the boot[12] args to where the BTX client can see them -# - movw $MEM_ARG, %si # where the args are at now - movw $MEM_ARG_BTX, %di # where the args are moving to - movw $(MEM_ARG_SIZE/4), %cx # size of the arguments in longs - rep # Relocate - movsl # the words -# -# Save the entry point so the client can get to it later on -# - movl end+AOUT_ENTRY, %eax # load the entry point - stosl # add it to the end of the - # arguments -# -# 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,0x0,0x9200,0x0 # SEL_RDATA - .word 0xffff,0x0,0x9a00,0xcf # SEL_SCODE (32-bit) - .word 0xffff,0x0,0x9a00,0x8f # SEL_SCODE16 (16-bit) -gdt.1: -# -# Pseudo-descriptors. -# -gdtdesc: .word gdt.1-gdt-1 # Limit - .long gdt # Base - -welcome_msg: .asciz "PXE 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" - - .p2align 4 -end: |
