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Make configurable (a) whether to use int 0x13 extensions; (b) timeout

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value.  Ignore failure to update mbr sector.  Disable interrupts while
using extended registers.  Default to F1 not F2.
This commit is contained in:
Robert Nordier 1998-10-19 19:13:53 +00:00
parent fbe55bf292
commit 4e108bf052
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=40524
3 changed files with 25 additions and 17 deletions
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9
sys/boot/i386/boot0/Makefile
View file

@ -1,4 +1,4 @@
# $Id: Makefile,v 1.4 1998/10/13 18:29:18 rnordier Exp $
# $Id: Makefile,v 1.5 1998/10/17 14:20:25 rnordier Exp $
PROG= boot0
NOMAN=
@ -8,6 +8,9 @@ BINMODE= 444
M4?= m4
B0FLAGS=0x0
B0TICKS=0xb6
ORG= 0x600
boot0: boot0.o
@ -20,8 +23,8 @@ boot0: boot0.o
.endif
boot0.o: boot0.m4 boot0.s
(cd ${.CURDIR}; ${M4} boot0.m4 boot0.s) | \
${AS} ${AFLAGS} -o ${.TARGET}
(cd ${.CURDIR}; ${M4} -DFLAGS=${B0FLAGS} -DTICKS=${B0TICKS} \
boot0.m4 boot0.s) | ${AS} ${AFLAGS} -o ${.TARGET}
CLEANFILES+= boot0.out boot0.o

3
sys/boot/i386/boot0/boot0.m4
View file

@ -13,7 +13,7 @@
# purpose.
#
# $Id:$
# $Id: boot0.m4,v 1.1.1.1 1998/10/05 10:08:37 rnordier Exp $
define(_al,0x0)dnl
define(_cl,0x1)dnl
@ -73,4 +73,5 @@ define(movwir,`.byte 0xb8 | $2; .word $1')dnl
define(movbi0,`.byte 0xc6; .byte $2; .byte $1')dnl
define(callwi,`.byte 0xe8; .word $1 - . - 0x2')dnl
define(jmpnwi,`.byte 0xe9; .word $1 - . - 0x2')dnl
define(tstbim,`.byte 0xf6; .byte 0x6; .word $2; .byte $1')dnl
define(incb1,`.byte 0xfe; .byte 0x40 | $2; .byte $1')dnl

30
sys/boot/i386/boot0/boot0.s
View file

@ -13,7 +13,7 @@
# purpose.
#
# $Id: boot0.s,v 1.2 1998/10/09 17:19:51 rnordier Exp $
# $Id: boot0.s,v 1.3 1998/10/10 14:03:03 rnordier Exp $
# A 512-byte boot manager.
@ -119,7 +119,6 @@ main.10: cwtl # Option
movwir(0x301,_ax) # Write sector
callwi(intx13) # to disk
popl %esi # Restore
jc main.5 # If error
main.11: movwir(LOAD,_bx) # Address for read
movwir(0x201,_ax) # Read sector
callwi(intx13) # from disk
@ -158,10 +157,21 @@ putchr: pushl %ebx # Save
# Disk I/O
intx13: movb1r(0x1,_si_,_dh) # Load head
intx13: cli # Disable interrupts
movb1r(0x1,_si_,_dh) # Load head
movw1r(0x2,_si_,_cx) # Load cylinder:sector
o16 # Load
movw1r(0x8,_si_,_di) # offset
movwir(break,_si) # Packet pointer
movbi0(0x10,_si_) # Packet size
movbr1(_al,0x2,_si_) # Block count
movwr1(_bx,0x4,_si_) # Transfer
movws1(_es,0x6,_si_) # buffer
o16 # LBA
movwr1(_di,0x8,_si_) # address
sti # Enable interrupts
tstbim(0x80,flags) # Try for extensions?
jz intx13.2 # No
pushl %ecx # Save
pushl %ebx # caller's
movwir(0x55aa,_bx) # Magic
@ -179,13 +189,6 @@ intx13.1: popl %ebx # Restore
popl %ecx # caller's
testb $0x40,%ah # Use EDD?
jz intx13.2 # No
movwir(break,_si) # Packet pointer
movbi0(0x10,_si_) # Packet size
movbr1(_al,0x2,_si_) # Block count
movwr1(_bx,0x4,_si_) # Transfer
movws1(_es,0x6,_si_) # buffer
o16 # LBA
movwr1(_di,0x8,_si_) # address
xorb %al,%al # Verify off
intx13.2: int $0x13 # BIOS: Disk I/O
ret # To caller
@ -221,10 +224,11 @@ os_linux: .ascii "Linu"; .byte 'x'|0x80
os_freebsd: .ascii "Free"
os_bsd: .ascii "BS"; .byte 'D'|0x80
.org PRT_OFF-0x3,0x90
.org PRT_OFF-0x4,0x90
opt: .byte 0x1 # Option
ticks: .word 0xb6 # Delay
opt: .byte 0x0 # Option
flags: .byte FLAGS # Flags
ticks: .word TICKS # Delay
partbl: .fill 0x40,0x1,0x0 # Partition table
.word 0xaa55 # Magic number