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Files
livingcomputermuseum.pdp7-unix/src/sys/s2.s
2016-03-03 21:14:35 -05:00

345 lines
6.4 KiB
ArmAsm

"** 01-s1.pdf page 7
" s2
.status:
jms arg
dac .+5
jms arg
dac .+6
lac u.cdir
jms namei; ..
jms error
jms namei; ..
jms error
jms iget
lac u.ac
and o17777
jms betwen; o10000; o17762
jms error
dac .+3
jms copy; inode; ..; 12
lac d.i
dac 9 i
jmp okexit
.capt:
lac u.ac
dac u.dspbuf
jms movdsp
jmp sysexit
.rele:
dzm u.dspbuf
law dspbuf
jms movdsp
jmp sysexit
.chmod:
jms isown
lac u.ac
and o17
lmq
lac i.flags
and o777760
omq
dac i.flags
jms iput
jmp okexit
.chown:
jms isown
lac u.ac
dac i.uid
jms iput
jmp okexit
.getuid: " getuid system call
lac u.uid
dac u.ac " return u.uid in user AC
jmp sysexit
.seek:
jms seektell
tad u.base
"** 01-s1.pdf page 8
spa
jms error
lmq
lac f.flags
and d1
sna
jms 1f
lacq
jms betwen; d0; i.size
jms dacisize
jmp 2f
1:
lacq
jms betwen; d0; i.size
lac i.size
2:
dac f.badd
dac u.ac
jms fput
jmp sysexit
.tell:
jms seektell
cma
tad d1
tad u.base
dac u.ac
jmp sysexit
.link:
jms arg
dac 0f
jms arg
dac 1f
jms arg
dac 2f
lac d4
jms namei; 0:0
jms error
jms namei; 1:0
jms error
dac u.base
jms copy; 2:0; name; 4
lac u.cdir
jms namei; name
skp
jms error
lac d1
dac mode " save mode bits for access
jms access
jms dslot
lac u.base
jms iget
lac ii
dzm d.i
jms copy; name; d.name; 4
lac i.uniq
dac d.uniq
-1
tad i.nlks
dac i.nlks
"** 01-s1.pdf page 9
jms iput
jms dput
jmp okexit
.unlink:
jms argname
dac u.base
lac d1 " mode bit 1 (write?)
dac mode " save for access call
jms access
dac d.i
jms dput
lac u.base
jms iget
isz i.nlks
jmp 1f
jms itrunc
dzm i.flags
1:
jms iput
jmp sysexit
.setuid: " setuid system call
lac u.uid " load current user id
sma " negative?
jms error " no: error!!
lac u.ac " load user AC
dac u.uid " save as new uid
jmp sysexit
.rename:
jms arg
dac 0f
jms arg
dac 1f
lac u.cdir
jms namei; 0:0
jms error
lac d1 " mode bit 1 (write?)
dac mode " save for access call
jms access
jms copy; 1:0; d.name; 4
jmp okexit
" time system call returns line (mains) frequency ticks since boot?
" note: returns uptime!?
" at 60Hz, 36 bits would last 36+ years!
.time:
lac s.tim " load high order bits
dac u.ac " return in AC
lac s.tim+1 " load low order bits
dac u.mq " return in MQ
jmp sysexit
.chdir:
jms argname
jms iget
lac i.flags
and o20
sna
jms error
lac ii
dac u.cdir
"** 01-s1.pdf page 10
jmp okexit
" open system call
" sys open; filename_ptr; flags (0 for read, 1 for write)
" returns w/ "fd" in AC (or -1 if not found)
.open:
jms arg " get filename
dac 0f " save for namei
jms arg " get flags
sza " zero (read)
lac d1 " no: get write mode bit
sna " non-zero (write)?
lac d2 " no: get read mode bot
dac mode " save for access call
lac u.cdir " get current working directory
jms namei; 0:0 " search for file
jms error " error: return -1
jms iget " load inode
jms access " check access (may return w/ error to user)
lac i.flags " get file flags
and o20 " get directory bit
sna " is directory?
jmp open1 " no, join common code
lac mode " get access mode
and d1 " get write bit
sna " write access?
jmp open1 " no, continue
lac u.uid " yes: get uid?
sma " negative? (-1 is superuser)
jms error " no: return error
jmp open1 " yes: join common code
.creat:
lac d1 " mode bit 1 (write)
dac mode " save for access call
jms arg
dac .+2
jms copy; ..; name; 4
lac u.cdir
jms namei; name
jmp 1f
jms iget
jms access
lac i.flags
and o20
sna
jmp .+4
lac u.uid
sma
jms error
jms itrunc
cla
jms dacisize
jmp open1
1:
jms access
lac u.ac " get access bits from user AC (zero for lock!)
and o17 " mask to permissions
jms icreat
open1: " common exit for open/creat
jms fassign " assign fd slot
jms error " none free, return -1
jmp sysexit
"** 01-s1.pdf page 11
.close:
jms finac
dzm f.flags
jms fput
jmp sysexit
.read:
jms arg
and o17777
dac u.base
jms arg
dac u.count
lac u.base
jms betwen; o10000; o17777
jms error
tad u.count
jms betwen; u.base; o17777
jms error
dac u.limit
1:
jms finac
lac f.flags
and d1
sza
jms error
lac i.flags " get inode flags
and o40 " get special file bit
sna " special?
jmp 1f " no
iof " yes: disable interrupts
lac ii " get i number
tad swr " get read routine table addr
dac .+1
jmp .. i " dispatch to read routine
1:
lac u.base " get user base
dac 1f+1 " save as iread base
lac u.count " get user count
dac 1f+2 " save as iread count
lac f.badd " get file offset
1:
jms iread; ..; ..
jmp exitrw
" write system call:
" AC/ fd
" sys write; buffer; count
" AC/ count or -1 on error
.write:
jms arg " pick up buffer
and o17777 " mask to addr
dac u.base " save as I/O base
jms arg " pick up count
dac u.count " save as count
tad u.base " add base (get limit)
jms betwen; u.base; o17777 " check between base and end of memory
jms error " no: error
dac u.limit " yes: save as limit
jms finac " get fnode with fd from user AC
lac f.flags " get open file table flags
and d1 " open for write?
sna " yes, skip
jms error " no: error
lac i.flags " get inode flags
and o40 " get special bit?
"** 01-s1.pdf page 12
sna " special?
jmp 1f " no
iof " special file (device node)
lac ii " get i number
tad sww " get write routine
dac .+1
jmp .. i " dispatch to write routine
1: " here with regular file
lac u.base " get base
dac 1f+1 " save as iwrite arg 1
lac u.count " get count
dac 1f+2 " save as iwrite 2
lac f.badd " get fd offset
1:
jms iwrite; ..; .. " write to file
exitrw: " common exit for read/write system calls
dac u.ac " save return in user AC
tad f.badd
dac f.badd " update file offset
jms iput " release inode
jms fput " release fnode
jmp sysexit " return to user