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Merge pull request #145 from philbudne/location7

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Improve sys annotations
This commit is contained in:
Phil Budne
2019-10-21 22:28:33 -04:00
committed by GitHub
parent 17c9581351 4b284c6bbe
commit 3ce29a2b02
5 changed files with 63 additions and 59 deletions
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src/sys/s1.s
+21 -17
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@@ -6,12 +6,16 @@ orig:
hlt " overwritten with interrupt return addr
jmp pibreak " dispatch to interrupt processing
. = orig+7
-1 " only ever set (to -1): never read?!
. = orig+7 " real time (60Hz) clock
-1 " -1 will cause "clock overflow" on next tick
" Overflow is checked by "clsf" instr
" in PI service (pibreak) routine,
" reset to -1 after tick handling
" results in an interrupt every "jiffy"
. = orig+020 " syscall (CAL) and user "interrupt" processing
1f " addr for "CAL I": store return here on "CAL"
iof " interrupts off
iof " here on CAL: interrupts off
dac u.ac " save user AC
lac 020 " save user return addr
dac 1f " save as if "CAL I"
@@ -22,29 +26,29 @@ orig:
1f " literal to restore location 20
1: 0 " "CAL I" PC stored here
iof " interrupts off
dac u.ac " save user AC
dac u.ac " save user AC in user area
lacq
dac u.mq " save user MQ
dac u.mq " save user MQ in user area
lac 8
dac u.rq " save user auto-index location 8
dac u.rq " save user auto-index location 8 in uarea
lac 9
dac u.rq+1 " save user auto-index location 9
jms copy; 10; u.rq+2; 6 " save user auto-index locations 10-15
lac 1b " load user PC after system call
dac u.rq+8 " save user PC
dac u.rq+1 " save auto-index location 9 in user area
jms copy; 10; u.rq+2; 6 " save auto-index locations 10-15 (using 8/9!)
lac 1b " load user PC
dac u.rq+8 " save in user area
-1 " load -1
dac .savblk " set "save" flag (cleared by disk I/O?)
dac .insys " set "in system" flag
lac uquant " load user quantum count
jms betwen; d0; maxquant " check if between 0 & maxquant??
jms swap " no: swap processes
lac uquant " load user quantum (tick) count
jms betwen; d0; maxquant " check if between 0 & maxquant (30 jiffies)
jms swap " no: quantum expired: swap process out
ion " interrupts on
-1
tad u.rq+8 " get address of system call
jms laci " load AC indirect??
jms betwen; o20001; swn " range check
jms laci " load system call instruction
jms betwen; o20001; swn " range check (expects CAL I!)
jmp badcal " bad system call
tad swp " add system call table base
tad swp " add "jmp syscall_table_base"
dac .+1 " save as next instruction
jmp .. i " dispatch system call
@@ -137,7 +141,7 @@ swp: " system call dispatch table
.chdir; .chmod; .chown; badcal; .sysloc; badcal; .capt; .rele
.status; badcal; .smes; .rmes; .fork
swn:
.-swp-1 i " count of system calls, plus indirect!
.-swp-1 i " last system call number: "CAL I n"
" AC/ new value for intflg (non-zero to ignore interrupt char)
" sys intrp
src/sys/s4.s
+22 -21
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@@ -56,8 +56,7 @@ free: 0
jmp free i " Return from the routine
t = t+1
" load AC indirect (without using indirect!)
" need to avoid use of indirect in interrupt service routines
" "load ac indirect"
" AC/ address
" jms laci
" AC/ contents of address
@@ -143,7 +142,7 @@ copyz: 0
t = t+1
" Character queue management routines
" (CALLED FROM PI: USE OF INDIRECT AVOIDED!)
" (CALLED FROM PI: USE OF INDIRECT AVOIDED TO AVOID DISK DMA UNDERRUN)
" Queue numbers:
" 0: free list
@@ -366,42 +365,44 @@ t = t+1
" perform disk I/O (both filesystem buffer and swapping)
" passed physical (BCD) disk address
" waits for disk interrupt: no overlapped operation
" to avoid disk DMA underrun
" called:
" jms dsktrans; -WC; MAC; addr_ptr; dsld_ptr
" jms dsktrans; -words; mem_addr; disk_addr_ptr; op_ptr_ptr
dsktrans: 0
-10
-10 " set retry counter
dac 9f+t
1:
-1
tad dsktrans
dac 12
tad dsktrans " get arg pointer
dac 12 " store as auto-index
"** 01-s1.pdf page 26
dscs " clear status register
lac 12 i
lac 12 i " pick up word count
dslw " load WC
lac 12 i
lac 12 i " pick up memory address
dslm " load MAC
lac 12 i
jms laci
dsld " load TA & SA
dzm .dskb
lac 12 i
jms laci
jms laci
dsls " load status
lac 12 i " get disk_addr_ptr
jms laci " get disk address
dsld " load BCD track and sector (TA & SA)
dzm .dskb " clear disk interrupt indicator
lac 12 i " load status (op) pointer pointer
jms laci " fetch pointer
jms laci " fetch op
dsls " load status register (sets busy, int enb)
lac .dskb " check for interrupt
sna
jmp .-2
jmp .-2 " loop until interrupt seen
lac .dske " get status from interrupt
sma
jmp 12 i " return
isz 9f+t
jmp 1b
isz 9f+t " increment retry counter
jmp 1b " less than 10 tries: try again
jms halt " 10 disk errors
t = t+1
halt: 0
isz 9f+t " spin for a while (process interrupts)
isz 9f+t " spin for a while (process interrupts?)
jmp .-1
iof " disable interrupts
hlt " halt
src/sys/s6.s
+7 -9
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@@ -270,12 +270,10 @@ t = t+3
" AC/ file offset
" jms iwrite; addr; count
iwrite: 0
iwrite: 0 " set to skp (or nop by iread)
dac 9f+t " save arg in t0
lac iwrite " load return address
"** 01-s1.pdf page 38
dac iread " save as iread return addr
lac cskp " load skip instruction
dac iwrite " save as iwrite instruction
@@ -287,7 +285,7 @@ iwrite: 0
iread: 0
dac 9f+t " save offset in t0
lac cnop " get nop
dac iwrite " save as iwrite instruction
dac iwrite " save in iwrite return location
1: " common code for iread/iwrite
-1
tad iread i " get word before return addr
@@ -322,17 +320,17 @@ iread: 0
tad dm1
xct iwrite " skip if write
jmp .+3
dac 10
cskp:
dac 10 " here on read
cskp: " literal for store to iwrite
skp
dac 11
dac 11 " here on write
2:
lac 11 i
dac 10 i
isz 9f+t
isz 9f+t+1
jmp 3f
xct iwrite
xct iwrite " skip if write
jmp 4f
lac 9f+t
jms betwen; d0; i.size
@@ -348,7 +346,7 @@ cskp:
and o77
sza
jmp 2b
xct iwrite
xct iwrite " skip if write
jmp 1b
lac 9f+t+3
jms dskwr
src/sys/s7.s
+12 -11
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@@ -25,23 +25,24 @@ pibreak: " priority interrupt break processing "chain"
dac dpwrite " dpwrite = -1
jmp piret "** END OF CROSSOUT
1: clsf " clock overflow (line frequency ticks)?
1: clsf " clock overflow (60hz tick increment of loc 7 (-1))
jmp 1f " no
lpb " load display push buttons
dac pbsflgs " save
isz s.tim+1 " increment low order tick count
skp " no overflow, skip second increment
skp " no overflow, skip high order word increment
isz s.tim " low order overflowed, increment high order count
isz uquant " increment user quantum counter
"** written: ttydelay -> ttyd1
" ("never" skips: 36 bits overflows every 36 years!)
isz uquant " increment user quantum counter (ignore overflow)
" (18 bits overflows in 72 minutes)
"** written: ttydelay -> ttyd1 ;
"** written: ttyrestart -> ttyres1
cnop: " fetched as constant in iread
nop
cnop: " constant location for iread (stored at iwrite!)
nop
-1
dac 7 " set location 7 to -1 (nothing ever checks/clears it?)
clon " enable clock interrupts, reset flag
dac 7 " reset rt clock count to -1 (overflow on next tick)
clon " enable clock interrupts, clear overflow flag
lac ttydelay " tty delay positive?
spa " yes: skip to skp
isz ttydelay " no: done delaying?
@@ -129,7 +130,7 @@ dsprestart:
jmp piret " no: done
lac sfiles+1 " get ttyout sleep word
sma " highest bit set?
xor o400000 " no, make it so (why???)
xor o400000 " no, make it so
dac sfiles+1 " save back
"** 01-s1.pdf page 43
@@ -168,7 +169,7 @@ ttyrestart: 0
tad o20 " bump by 16
rcr " divide by two
cma " complement
dac ttydelay " save
dac ttydelay " save as delay countdown
jmp ttyrestart i
2:
lac sfiles+1 " run out of characters to send: wake user(s)
src/sys/s8.s
+1 -1
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@@ -123,7 +123,7 @@ coldentry:
dzm 0100 " not re-entrant
caf " clear all flags
ion " enable interrupts
clon " clear clock flag
clon " clear clock overflow flag
law 3072 " initialize display....
wcga
jms dspinit