| pxeldr.S (58713) | pxeldr.S (60821) |
|---|---|
| 1# 2# Copyright (c) 2000 John Baldwin 3# All rights reserved. 4# 5# Redistribution and use in source and binary forms are freely 6# permitted provided that the above copyright notice and this 7# paragraph and the following disclaimer are duplicated in all 8# such forms. 9# 10# This software is provided "AS IS" and without any express or 11# implied warranties, including, without limitation, the implied 12# warranties of merchantability and fitness for a particular 13# purpose. 14# 15 | 1# 2# Copyright (c) 2000 John Baldwin 3# All rights reserved. 4# 5# Redistribution and use in source and binary forms are freely 6# permitted provided that the above copyright notice and this 7# paragraph and the following disclaimer are duplicated in all 8# such forms. 9# 10# This software is provided "AS IS" and without any express or 11# implied warranties, including, without limitation, the implied 12# warranties of merchantability and fitness for a particular 13# purpose. 14# 15 |
| 16# $FreeBSD: head/sys/boot/i386/pxeldr/pxeldr.S 58713 2000-03-28 01:19:53Z jhb $ | 16# $FreeBSD: head/sys/boot/i386/pxeldr/pxeldr.S 60821 2000-05-23 12:18:49Z jhb $ |
| 17 18# 19# This simple program is a preloader for the normal boot3 loader. It is simply 20# prepended to the beginning of a fully built and btxld'd loader. It then 21# copies the loader to the address boot2 normally loads it, emulates the 22# boot[12] environment (protected mode, a bootinfo struct, etc.), and then jumps 23# to the start of btxldr to start the boot process. This method allows a stock 24# /boot/loader to be booted over the network via PXE w/o having to write a --- 55 unchanged lines hidden (view full) --- 80 movw %ax, %ds # setup the 81 movw %ax, %es # data segments 82 andl $0xffff, %ecx # clear upper words 83 andl $0xffff, %ebx # of %ebx and %ecx 84 shll $4, %ecx # calculate the offset of 85 addl %ebx, %ecx # the PXENV+ struct and 86 pushl %ecx # save it on the stack 87 movw $welcome_msg, %si # %ds:(%si) -> welcome message | 17 18# 19# This simple program is a preloader for the normal boot3 loader. It is simply 20# prepended to the beginning of a fully built and btxld'd loader. It then 21# copies the loader to the address boot2 normally loads it, emulates the 22# boot[12] environment (protected mode, a bootinfo struct, etc.), and then jumps 23# to the start of btxldr to start the boot process. This method allows a stock 24# /boot/loader to be booted over the network via PXE w/o having to write a --- 55 unchanged lines hidden (view full) --- 80 movw %ax, %ds # setup the 81 movw %ax, %es # data segments 82 andl $0xffff, %ecx # clear upper words 83 andl $0xffff, %ebx # of %ebx and %ecx 84 shll $4, %ecx # calculate the offset of 85 addl %ebx, %ecx # the PXENV+ struct and 86 pushl %ecx # save it on the stack 87 movw $welcome_msg, %si # %ds:(%si) -> welcome message |
| 88 call putstr # display the welcome message | 88 callw putstr # display the welcome message |
| 89# 90# Setup the arguments that the loader is expecting from boot[12] 91# 92 movw $bootinfo_msg, %si # %ds:(%si) -> boot args message | 89# 90# Setup the arguments that the loader is expecting from boot[12] 91# 92 movw $bootinfo_msg, %si # %ds:(%si) -> boot args message |
| 93 call putstr # display the message 94 movl $MEM_ARG, %ebx # %ds:(%ebx) -> boot args | 93 callw putstr # display the message 94 movl $MEM_ARG, %bx # %ds:(%bx) -> boot args |
| 95 movw %bx, %di # %es:(%di) -> boot args 96 xorl %eax, %eax # zero %eax 97 movw $(MEM_ARG_SIZE/4), %cx # Size of arguments in 32-bit 98 # dwords 99 rep # Clear the arguments 100 stosl # to zero | 95 movw %bx, %di # %es:(%di) -> boot args 96 xorl %eax, %eax # zero %eax 97 movw $(MEM_ARG_SIZE/4), %cx # Size of arguments in 32-bit 98 # dwords 99 rep # Clear the arguments 100 stosl # to zero |
| 101 orb $KARGS_FLAGS_PXE, 0x8(%ebx) # kargs->bootflags |= | 101 orb $KARGS_FLAGS_PXE, 0x8(%bx) # kargs->bootflags |= |
| 102 # KARGS_FLAGS_PXE | 102 # KARGS_FLAGS_PXE |
| 103 popl 0xc(%ebx) # kargs->pxeinfo = *PXENV+ | 103 popl 0xc(%bx) # kargs->pxeinfo = *PXENV+ |
| 104# 105# Turn on the A20 address line 106# | 104# 105# Turn on the A20 address line 106# |
| 107 call seta20 # Turn A20 on | 107 callw seta20 # Turn A20 on |
| 108# 109# Relocate the loader and BTX using a very lazy protected mode 110# 111 movw $relocate_msg, %si # Display the | 108# 109# Relocate the loader and BTX using a very lazy protected mode 110# 111 movw $relocate_msg, %si # Display the |
| 112 call putstr # relocation message | 112 callw putstr # relocation message |
| 113 movl end+AOUT_ENTRY, %edi # %edi is the destination 114 movl $(end+AOUT_HEADER), %esi # %esi is 115 # the start of the text 116 # segment 117 movl end+AOUT_TEXT, %ecx # %ecx = length of the text 118 # segment 119 lgdt gdtdesc # setup our own gdt 120 cli # turn off interrupts 121 movl %cr0, %eax # Turn on 122 orb $0x1, %al # protected 123 movl %eax, %cr0 # mode | 113 movl end+AOUT_ENTRY, %edi # %edi is the destination 114 movl $(end+AOUT_HEADER), %esi # %esi is 115 # the start of the text 116 # segment 117 movl end+AOUT_TEXT, %ecx # %ecx = length of the text 118 # segment 119 lgdt gdtdesc # setup our own gdt 120 cli # turn off interrupts 121 movl %cr0, %eax # Turn on 122 orb $0x1, %al # protected 123 movl %eax, %cr0 # mode |
| 124 .byte 0xea # long jump to 125 .word pm_start # clear the instruction 126 .word SEL_SCODE # pre-fetch queue | 124 ljmp $SEL_SCODE,$pm_start # long jump to clear the 125 # instruction pre-fetch queue |
| 127 .code32 128pm_start: movw $SEL_SDATA, %ax # Initialize 129 movw %ax, %ds # %ds and 130 movw %ax, %es # %es to a flat selector 131 rep # Relocate the 132 movsb # text segment 133 addl $(MEM_PAGE_SIZE - 1), %edi # pad %edi out to a new page 134 andl $~(MEM_PAGE_SIZE - 1), %edi # for the data segment --- 15 unchanged lines hidden (view full) --- 150 ljmp $SEL_SCODE16,$pm_16 # Jump to 16-bit PM 151 .code16 152pm_16: movw $SEL_RDATA, %ax # Initialize 153 movw %ax, %ds # %ds and 154 movw %ax, %es # %es to a real mode selector 155 movl %cr0, %eax # Turn off 156 andb $~0x1, %al # protected 157 movl %eax, %cr0 # mode | 126 .code32 127pm_start: movw $SEL_SDATA, %ax # Initialize 128 movw %ax, %ds # %ds and 129 movw %ax, %es # %es to a flat selector 130 rep # Relocate the 131 movsb # text segment 132 addl $(MEM_PAGE_SIZE - 1), %edi # pad %edi out to a new page 133 andl $~(MEM_PAGE_SIZE - 1), %edi # for the data segment --- 15 unchanged lines hidden (view full) --- 149 ljmp $SEL_SCODE16,$pm_16 # Jump to 16-bit PM 150 .code16 151pm_16: movw $SEL_RDATA, %ax # Initialize 152 movw %ax, %ds # %ds and 153 movw %ax, %es # %es to a real mode selector 154 movl %cr0, %eax # Turn off 155 andb $~0x1, %al # protected 156 movl %eax, %cr0 # mode |
| 158 .byte 0xea # Long jump to 159 .word pm_end # clear the instruction 160 .word 0x0 # pre-fetch | 157 ljmp $0,$pm_end # Long jump to clear the 158 # instruction pre-fetch queue |
| 161pm_end: sti # Turn interrupts back on now 162# 163# Copy the BTX client to MEM_BTX_CLIENT 164# 165 xorw %ax, %ax # zero %ax and set 166 movw %ax, %ds # %ds and %es 167 movw %ax, %es # to segment 0 168 movw $MEM_BTX_CLIENT, %di # Prepare to relocate --- 14 unchanged lines hidden (view full) --- 183# 184 movl end+AOUT_ENTRY, %eax # load the entry point 185 stosl # add it to the end of the 186 # arguments 187# 188# Now we just start up BTX and let it do the rest 189# 190 movw $jump_message, %si # Display the | 159pm_end: sti # Turn interrupts back on now 160# 161# Copy the BTX client to MEM_BTX_CLIENT 162# 163 xorw %ax, %ax # zero %ax and set 164 movw %ax, %ds # %ds and %es 165 movw %ax, %es # to segment 0 166 movw $MEM_BTX_CLIENT, %di # Prepare to relocate --- 14 unchanged lines hidden (view full) --- 181# 182 movl end+AOUT_ENTRY, %eax # load the entry point 183 stosl # add it to the end of the 184 # arguments 185# 186# Now we just start up BTX and let it do the rest 187# 188 movw $jump_message, %si # Display the |
| 191 call putstr # jump message 192 .byte 0xea # Jump to 193 .word MEM_BTX_ENTRY # BTX entry 194 .word 0x0 # point | 189 callw putstr # jump message 190 ljmp $0,$MEM_BTX_ENTRY # Jump to the BTX entry point |
| 195 196# 197# Display a null-terminated string 198# 199putstr: lodsb # load %al from %ds:(%si) 200 testb %al,%al # stop at null 201 jnz putc # if the char != null, output it | 191 192# 193# Display a null-terminated string 194# 195putstr: lodsb # load %al from %ds:(%si) 196 testb %al,%al # stop at null 197 jnz putc # if the char != null, output it |
| 202 ret # return when null is hit | 198 retw # return when null is hit |
| 203putc: movw $0x7,%bx # attribute for output 204 movb $0xe,%ah # BIOS: put_char 205 int $0x10 # call BIOS, print char in %al 206 jmp putstr # keep looping 207 208# 209# Enable A20 210# --- 4 unchanged lines hidden (view full) --- 215 movb $0xd1,%al # Command: Write 216 outb %al,$0x64 # output port 217seta20.2: inb $0x64,%al # Get status 218 testb $0x2,%al # Busy? 219 jnz seta20.2 # Yes 220 movb $0xdf,%al # Enable 221 outb %al,$0x60 # A20 222 sti # Enable interrupts | 199putc: movw $0x7,%bx # attribute for output 200 movb $0xe,%ah # BIOS: put_char 201 int $0x10 # call BIOS, print char in %al 202 jmp putstr # keep looping 203 204# 205# Enable A20 206# --- 4 unchanged lines hidden (view full) --- 211 movb $0xd1,%al # Command: Write 212 outb %al,$0x64 # output port 213seta20.2: inb $0x64,%al # Get status 214 testb $0x2,%al # Busy? 215 jnz seta20.2 # Yes 216 movb $0xdf,%al # Enable 217 outb %al,$0x60 # A20 218 sti # Enable interrupts |
| 223 ret # To caller | 219 retw # To caller |
| 224 225# 226# BTX client to start btxldr 227# 228 .code32 229btx_client: movl $(MEM_ARG_BTX-MEM_BTX_CLIENT+MEM_ARG_SIZE-4), %esi 230 # %ds:(%esi) -> end 231 # of boot[12] args --- 36 unchanged lines hidden --- | 220 221# 222# BTX client to start btxldr 223# 224 .code32 225btx_client: movl $(MEM_ARG_BTX-MEM_BTX_CLIENT+MEM_ARG_SIZE-4), %esi 226 # %ds:(%esi) -> end 227 # of boot[12] args --- 36 unchanged lines hidden --- |