2.9BSD/usr/src/sys/stand/bootstrap/M.s
/
/ SCCS id @(#)M.s 1.7 (Berkeley) 7/11/83
/
/ Startup code for two-stage bootstrap
/ With support for UCB_AUTOBOOT
/ Supports 11/40, 11/45, 11/70, 11/23, 11/23+I/O map (11/24)
/ and similar machines
/ non-UNIX instructions
mfpi = 6500^tst
stst = 170300^tst
mtpi = 6600^tst
mfpd = 106500^tst
mtpd = 106600^tst
spl = 230
ldfps = 170100^tst
stfps = 170200^tst
wait = 1
rtt = 6
halt = 0
reset = 5
systrap = 104400
/ The boot options and device are placed in the last SZFLAGS bytes
/ at the end of core by the kernel if this is an autoboot.
/ The first-stage boot will leave them in registers for us;
/ we clobber possible old flags so that they don't get re-used.
ENDCORE= 160000 / end of core, mem. management off
SZFLAGS= 6 / size of boot flags
BOOTOPTS= 2 / location of options, bytes below ENDCORE
BOOTDEV= 4
CHECKWORD= 6
.globl _end
.globl _main,_ubmapset
jmp start
/
/ trap vectors
/
trap;340 / bus error -- grok!
trap;341 / illegal instruction
trap;342 / BPT
trap;343 / IOT
trap;344 / POWER FAIL
trap;345 / EMT
tvec:
start;346 / TRAP
.=400^.
start:
reset
mov $340,PS
mov $140100,sp
/save boot options, if present
mov r4,_bootopts
mov r3,_bootdev
mov r2,_checkword
/clobber any boot flags left in memory
clr ENDCORE-BOOTOPTS
clr ENDCORE-BOOTDEV
clr ENDCORE-CHECKWORD
/
/ determine what kind of cpu we are running on
/ first, check switches. if they are 40, 24, 45 or 70
/ set appropriately
/
clrb _sep_id
clrb _ubmap
clrb _haveCSW
mov $2f,nofault / check if we even have switches!
tst *$SWREG
clr nofault / apparently we do
incb _haveCSW
mov $40.,r0
cmp *$SWREG,$40
beq gotcha
cmp *$SWREG,$24
bne 1f
mov $24.,r0
incb _ubmap
jbr gotcha
1:
cmp *$SWREG,$45
bne 1f
mov $45.,r0
incb _sep_id
jbr gotcha
1:
cmp *$SWREG,$70
bne 2f
mov $70.,r0
incb _sep_id
incb _ubmap
jbr gotcha
/
/ if we can't find out from switches,
/ explore and see what we find
/
2:
mov $40.,r0 / assume 11/40
mov $2f,nofault
mov *$KDSA6,r1 / then we have sep i/d
incb _sep_id
mov $45.,r0
mov $1f,nofault
mov *$UBMAP,r1 / then we have a unibus map
incb _ubmap
mov $70.,r0
br 1f
2:
mov $1f,nofault
mov *$UBMAP,r1 / then we have a unibus map
incb _ubmap
mov $24.,r0 / unibus map, no sep. I/D = 24
1: clr nofault
gotcha:
mov r0,_cputype
/
/ Set kernel I space registers to physical 0 and I/O page
/
clr r1
mov $77406, r2
mov $KISA0, r3
mov $KISD0, r4
jsr pc, setseg
mov $IO, -(r3)
/
/ Set user I space registers to physical 128kb and I/O page
/
mov $4000, r1 / 04000 = 128*1024/64
mov $UISA0, r3
mov $UISD0, r4
jsr pc, setseg
mov $IO, -(r3)
/
/ If 11/40 class processor, only need set the I space registers
/
tstb _sep_id
jeq 1f
/
/ Set kernel D space registers to physical 0 and I/O page
/
clr r1
mov $KDSA0, r3
mov $KDSD0, r4
jsr pc, setseg
mov $IO, -(r3)
/
/ Set user D space registers to physical 128kb and I/O page
/
mov $4000, r1 / 04000 = 128*1024/64
mov $UDSA0, r3
mov $UDSD0, r4
jsr pc, setseg
mov $IO, -(r3)
1:
/ enable map
clrb _ksep
tstb _ubmap
beq 2f
jsr pc,_ubmapset
tstb _sep_id
bne 3f
mov $60,SSR3 / 22-bit map, no separation
br 1f
3:
mov $65,SSR3 / 22-bit map, sep. I/D user and kernel
movb $1,_ksep
cmp _cputype,$70.
jne 1f
mov $3,MSCR
br 1f
2:
tstb _sep_id / no ubmap; sep_id?
beq 1f
mov $5,SSR3
movb $1,_ksep
1:
mov $30340,PS
inc SSR0
/ copy program to user I space
mov $_end,r0
asr r0
clr r1
1:
mov (r1),-(sp)
mtpi (r1)+
sob r0,1b
/ continue execution in user space copy
mov $140004,sp
tstb _sep_id
bne 1f
clr *$KISA6
br 2f
1:
clr *$KDSA6
2: mov $140340,-(sp)
mov $user,-(sp)
rtt
user:
/ clear bss
mov $_edata,r0
mov $_end,r1
sub r0,r1
inc r1
clc
ror r1
1:
clr (r0)+
sob r1,1b
mov $_end+512.,sp
mov sp,r5
jsr pc,_main
mov _cputype,r0
mov _bootopts,r4
mov r4,r2
com r2 / checkword
systrap
br user
setseg:
mov $8,r0
1:
mov r1,(r3)+
add $200,r1
mov r2,(r4)+
sob r0,1b
rts pc
.globl _setseg
_setseg:
mov 2(sp),r1
mov r2,-(sp)
mov r3,-(sp)
mov r4,-(sp)
mov $77406,r2
mov $KISA0,r3
mov $KISD0,r4
jsr pc,setseg
tstb _ksep
bne 1f
mov $IO,-(r3)
1:
mov (sp)+,r4
mov (sp)+,r3
mov (sp)+,r2
rts pc
.globl _setnosep
_setnosep:
bic $4,SSR3 / turn off kernel i/d sep
clrb _ksep
rts pc
.globl _setsep
_setsep:
bis $4,SSR3 / turn on kernel i/d sep (if not already)
movb $1,_ksep
rts pc
/ Relocate higher in memory for large kernel.
.globl _reloc, _segflag
_reloc:
jsr r5, csv
mov $2f, nofault
/ Set Kernel I to point to new area
mov $6000, r1 / 192 KB
mov $77406,r2
mov $KISA0, r3
mov $KISD0, r4
jsr pc, setseg
/ Copy to new area
clr r0
mov $28.*1024., r1 / 28 K words
1:
mov (r0), -(sp)
mtpi (r0)+
sob r1, 1b
clr nofault
/ Repoint kernel I at 0.
clr -(sp)
jsr pc, _setseg
tst (sp)+
/ Point User D at new area
tstb _sep_id
beq 1f
mov $6000, r1 / 192 KB
mov $UDSA0, r3
mov $UDSD0, r4
jsr pc, setseg
mov $IO, -(r3)
/ Now User I-- execution switches to new copy.
1:
mov $6000, r1 / 192 KB
mov $UISA0, r3
mov $UISD0, r4
mov $7,r0
1:
mov r1,(r3)+
add $200,r1
mov r2,(r4)+
sob r0,1b
mov $3, _segflag / new extension bits
clr r0 / success
jmp cret
/ Trap here on bus error (not enough memory)
2:
mov $-1, r0
jmp cret
/ clrseg(addr,count)
.globl _clrseg
_clrseg:
mov 4(sp),r0
beq 2f
asr r0
bic $!77777,r0
mov 2(sp),r1
1:
clr -(sp)
mtpi (r1)+
sob r0,1b
2:
rts pc
/ mtpd(word,addr)
.globl _mtpd
_mtpd:
mov 4(sp),r0
mov 2(sp),-(sp)
mtpd (r0)+
rts pc
/ mtpi(word,addr)
.globl _mtpi
_mtpi:
mov 4(sp),r0
mov 2(sp),-(sp)
mtpi (r0)+
rts pc
.globl __rtt
__rtt:
halt
.globl _trap
trap:
mov *$PS,-(sp)
mov r0,-(sp)
mov r1,-(sp)
tst nofault
bne 3f
jsr pc,_trap
mov (sp)+,r1
mov (sp)+,r0
tst (sp)+
rtt
3: mov (sp)+,r1
mov (sp)+,r0
tst (sp)+
mov nofault,(sp)
rtt
PS = 177776
SSR0 = 177572
SSR1 = 177574
SSR2 = 177576
SSR3 = 172516
KISA0 = 172340
KISA1 = 172342
KISA6 = 172354
KISA7 = 172356
KISD0 = 172300
KISD7 = 172316
KDSA0 = 172360
KDSA6 = 172374
KDSA7 = 172376
KDSD0 = 172320
KDSD5 = 172332
SISA0 = 172240
SISA1 = 172242
SISD0 = 172200
SISD1 = 172202
UISA0 = 177640
UISD0 = 177600
UDSA0 = 177660
UDSD0 = 177620
MSCR = 017777746 / 11/70 memory control register
IO = 177600
SWREG = 177570
UBMAP = 170200
.data
.globl _cputype
.globl _ksep, _sep_id, _ubmap, _haveCSW
.globl _bootopts, _bootdev, _checkword
nofault: .=.+2 / where to go on predicted trap
_cputype: .=.+2 / cpu type (currently 40,45 or 70)
_sep_id: .=.+1 / 1 if we have separate I and D
_ubmap: .=.+1 / 1 if we have a unibus map
_haveCSW: .=.+1 / 1 if we have a console switch register
_ksep: .=.+1 / 1 if kernel mode has sep I/D enabled
_bootopts: .=.+2 / flags if an autoboot
_bootdev: .=.+2 / device to get unix from, if not RB_ASKNAME
_checkword: .=.+2 / saved r2, complement of bootopts if an autoboot