| cdboot.S (130943) | cdboot.S (157652) |
|---|---|
| 1# 2# Copyright (c) 2001 John Baldwin <jhb@FreeBSD.org> 3# All rights reserved. 4# 5# Redistribution and use in source and binary forms, with or without 6# modification, are permitted provided that the following conditions 7# are met: 8# 1. Redistributions of source code must retain the above copyright --- 13 unchanged lines hidden (view full) --- 22# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27# SUCH DAMAGE. 28# 29 | 1# 2# Copyright (c) 2001 John Baldwin <jhb@FreeBSD.org> 3# All rights reserved. 4# 5# Redistribution and use in source and binary forms, with or without 6# modification, are permitted provided that the following conditions 7# are met: 8# 1. Redistributions of source code must retain the above copyright --- 13 unchanged lines hidden (view full) --- 22# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27# SUCH DAMAGE. 28# 29 |
| 30# $FreeBSD: head/sys/boot/i386/cdboot/cdboot.s 130943 2004-06-22 21:55:22Z jhb $ | 30# $FreeBSD: head/sys/boot/i386/cdboot/cdboot.s 157652 2006-04-11 04:39:29Z sobomax $ |
| 31 32# 33# This program is a freestanding boot program to load an a.out binary 34# from a CD-ROM booted with no emulation mode as described by the El 35# Torito standard. Due to broken BIOSen that do not load the desired 36# number of sectors, we try to fit this in as small a space as possible. 37# 38# Basically, we first create a set of boot arguments to pass to the loaded --- 441 unchanged lines hidden (view full) --- 480 call putc # Output it 481 mov $8,%al # Backspace 482 call putc # Output it 483 pop %bx # Restore 484 pop %ax # Restore 485 ret 486 487# | 31 32# 33# This program is a freestanding boot program to load an a.out binary 34# from a CD-ROM booted with no emulation mode as described by the El 35# Torito standard. Due to broken BIOSen that do not load the desired 36# number of sectors, we try to fit this in as small a space as possible. 37# 38# Basically, we first create a set of boot arguments to pass to the loaded --- 441 unchanged lines hidden (view full) --- 480 call putc # Output it 481 mov $8,%al # Backspace 482 call putc # Output it 483 pop %bx # Restore 484 pop %ax # Restore 485 ret 486 487# |
| 488# Enable A20 | 488# Enable A20. Put upper limit on amount of time we wait for the 489# keyboard controller to get ready (65K x ISA access time). If 490# we wait more than that amount it's likely that the hardware 491# is legacy-free and simply doesn't have keyboard controller 492# and don't need enabling A20 at all. |
| 489# 490seta20: cli # Disable interrupts | 493# 494seta20: cli # Disable interrupts |
| 491seta20.1: in $0x64,%al # Get status | 495 xor %cx,%cx # Clear 496seta20.1: inc %cx # Increment, overflow? 497 jz seta20.3 # Yes 498 in $0x64,%al # Get status |
| 492 test $0x2,%al # Busy? 493 jnz seta20.1 # Yes 494 mov $0xd1,%al # Command: Write 495 out %al,$0x64 # output port 496seta20.2: in $0x64,%al # Get status 497 test $0x2,%al # Busy? 498 jnz seta20.2 # Yes 499 mov $0xdf,%al # Enable 500 out %al,$0x60 # A20 | 499 test $0x2,%al # Busy? 500 jnz seta20.1 # Yes 501 mov $0xd1,%al # Command: Write 502 out %al,$0x64 # output port 503seta20.2: in $0x64,%al # Get status 504 test $0x2,%al # Busy? 505 jnz seta20.2 # Yes 506 mov $0xdf,%al # Enable 507 out %al,$0x60 # A20 |
| 501 sti # Enable interrupts | 508seta20.3: sti # Enable interrupts |
| 502 ret # To caller 503 504# 505# Convert AL to hex, saving the result to [EDI]. 506# 507hex8: pushl %eax # Save 508 shrb $0x4,%al # Do upper 509 call hex8.1 # 4 --- 84 unchanged lines hidden --- | 509 ret # To caller 510 511# 512# Convert AL to hex, saving the result to [EDI]. 513# 514hex8: pushl %eax # Save 515 shrb $0x4,%al # Do upper 516 call hex8.1 # 4 --- 84 unchanged lines hidden --- |