glm94/pdp7-unix
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Merge branch 'master' of https://github.com/DoctorWkt/pdp7-unix

Browse Source
This commit is contained in:
Warren Toomey
2016-03-16 05:37:25 +10:00
parent 00c2de0292 8b3ac73639
commit b4891828de
4 changed files with 164 additions and 140 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/sys/s2.s
+117 -103
View File
@@ -1,33 +1,38 @@
"** 01-s1.pdf page 7 "** 01-s1.pdf page 7
" s2 " s2
" file status (stat) system call
" AC/ pointer to status (inode) buffer (12 words)
" sys status; dir_name_ptr; file_name_ptr
.status: .status:
jms arg jms arg " fetch directory name pointer
dac .+5 dac .+5
jms arg jms arg " fetch file name pointer
dac .+6 dac .+6
lac u.cdir lac u.cdir " get current working directory
jms namei; .. jms namei; .. " look up source directory
jms error jms error " not found: return error to user
jms namei; .. jms namei; .. " look up file
jms error jms error " not found: return error
jms iget jms iget " read file inode
lac u.ac lac u.ac " get user buffer pointer
and o17777 and o17777 " truncate to 13 bits
jms betwen; o10000; o17762 jms betwen; o10000; o17762 " is user memory (but not last 14 wds)?
jms error jms error " no: error
dac .+3 dac .+3 " save as copy destination
jms copy; inode; ..; 12 jms copy; inode; ..; 12 " copy inode to user buffer
lac d.i lac d.i " copy i-num from last dnode read ??
dac 9 i dac 9 i " save thru index 9 (pre-increment) ??
jmp okexit jmp okexit
" capture display?
.capt: .capt:
lac u.ac lac u.ac
dac u.dspbuf dac u.dspbuf
jms movdsp jms movdsp
jmp sysexit jmp sysexit
" release display?
.rele: .rele:
dzm u.dspbuf dzm u.dspbuf
law dspbuf law dspbuf
@@ -35,22 +40,22 @@
jmp sysexit jmp sysexit
.chmod: .chmod:
jms isown jms isown " check if user owns file arg
lac u.ac lac u.ac " get new permissions
and o17 and o17 " mask to read/write bits
lmq lmq " save in MQ
lac i.flags lac i.flags " get file flags
and o777760 and o777760 " clear permissions
omq omq " or in new permissions from MQ
dac i.flags dac i.flags " save in inode
jms iput jms iput " write inode back
jmp okexit jmp okexit
.chown: .chown:
jms isown jms isown " check if user owns file arg
lac u.ac lac u.ac " get new owner
dac i.uid dac i.uid " save in inode
jms iput jms iput " write inode back
jmp okexit jmp okexit
.getuid: " getuid system call .getuid: " getuid system call
@@ -103,7 +108,7 @@
jms error " Didn't find it jms error " Didn't find it
jms namei; 1:0 " In the i-num found by 1st namei, jms namei; 1:0 " In the i-num found by 1st namei,
jms error " search for 2nd argument, err not found jms error " search for 2nd argument, err not found
dac u.base dac u.base " save in user data
jms copy; 2:0; name; 4 jms copy; 2:0; name; 4
lac u.cdir " Search the process' current directory lac u.cdir " Search the process' current directory
jms namei; name " for the third argument jms namei; name " for the third argument
@@ -111,11 +116,11 @@
jms error " Error if it already exists jms error " Error if it already exists
lac d1 lac d1
dac mode " Save mode bits for access dac mode " Save mode bits for access
jms access jms access " check access (or return error to user)
jms dslot " ??? jms dslot " allocate directory slot
lac u.base " ??? lac u.base " get source file i-number
jms iget " ??? jms iget " read inode in
lac ii " ??? lac ii " get the i-num
dac d.i " Save the i-num in the directory entry dac d.i " Save the i-num in the directory entry
jms copy; name; d.name; 4 " Copy the new link name into the directory entry jms copy; name; d.name; 4 " Copy the new link name into the directory entry
lac i.uniq " Copy the i-node unique number into lac i.uniq " Copy the i-node unique number into
@@ -129,47 +134,56 @@
jmp okexit " and return OK jmp okexit " and return OK
.unlink: .unlink:
jms argname jms argname " fetch filename, inode
dac u.base dac u.base " save i-number
lac d1 " mode bit 1 (write?) lac d1 " write mode bit
dac mode " save for access call dac mode " save for access call
jms access jms access " check access or return error (reads inode)
dac d.i dzm d.i " clear directory i-num
jms dput jms dput " write directory entry back
lac u.base lac u.base " get i-number back
jms iget jms iget " read inode back
isz i.nlks " increment link count isz i.nlks " increment link count (kept as negative count)
jmp 1f " not zero jmp 1f " not zero
jms itrunc " zero links: free blocks jms itrunc " zero links: free blocks
dzm i.flags " clear status (free inode) dzm i.flags " clear status (free inode)
1: 1:
jms iput jms iput " write inode back to disk
jmp sysexit jmp sysexit
.setuid: " setuid system call .setuid: " setuid system call
lac u.uid " load current user id lac u.uid " load current user id
sma " negative? sma " negative (super user)
jms error " no: error!! jms error " no: error!!
lac u.ac " load user AC lac u.ac " load user AC
dac u.uid " save as new uid dac u.uid " save as new uid
jmp sysexit jmp sysexit
" rename system call:
" sys rename; old_name_ptr; new_name_ptr
" Questions:
" when is directory entry read??
" is access check on directory or src file??
" check for existing file with new name??
" when is directory entry written back??
.rename: .rename:
jms arg jms arg " fetch first arg (old name pointer)
dac 0f dac 0f " save for namei
jms arg jms arg " fetch second arg (new name pointer)
dac 1f dac 1f " save for copy
lac u.cdir lac u.cdir " get CWD
jms namei; 0:0 jms namei; 0:0 " search for (old) name
jms error jms error " not found: return error
lac d1 " mode bit 1 (write?) lac d1 " get write mode bit
dac mode " save for access call dac mode " save for access call
jms access jms access " access OK? (or return error to user)
jms copy; 1:0; d.name; 4 jms copy; 1:0; d.name; 4 " copy new name into directory entry
jmp okexit jmp okexit
" time system call returns line (mains) frequency ticks since boot? " time system call returns line (mains) frequency ticks
" note: returns uptime!? " high order bits returned in AC, low order in MQ
" s.tim is located in "system" block (written to disk)
" so this is a running count of uptime since first boot!
" at 60Hz, 36 bits would last 36+ years! " at 60Hz, 36 bits would last 36+ years!
.time: .time:
lac s.tim " load high order bits lac s.tim " load high order bits
@@ -179,14 +193,14 @@
jmp sysexit jmp sysexit
.chdir: .chdir:
jms argname jms argname " fetch argument as filename
jms iget jms iget " (re)read inode(???)
lac i.flags lac i.flags " get flags
and o20 and o20 " get directory bit
sna sna " is a directory?
jms error jms error " no: return error to user
lac ii lac ii " yes: get i-number
dac u.cdir dac u.cdir " save as current working directory
"** 01-s1.pdf page 10 "** 01-s1.pdf page 10
jmp okexit jmp okexit
@@ -223,27 +237,27 @@
.creat: .creat:
lac d1 " mode bit 1 (write) lac d1 " mode bit 1 (write)
dac mode " save for access call dac mode " save for access call
jms arg jms arg " get name pointer
dac .+2 dac .+2 " save for copy
jms copy; ..; name; 4 jms copy; ..; name; 4 " copy filename to "name"
lac u.cdir lac u.cdir
jms namei; name jms namei; name " look up in current working directory
jmp 1f jmp 1f " not found
jms iget jms iget " file exists: read inode
jms access jms access " check access (or return error to user)
lac i.flags lac i.flags " get flags
and o20 and o20 " get directory bit
sna sna " is a directory?
jmp .+4 jmp .+4 " no: skip to truncate
lac u.uid lac u.uid " get user
sma sma " is super user?
jms error jms error " no: error
jms itrunc jms itrunc " yes: truncate
cla cla
jms dacisize jms dacisize " clear i.size
jmp open1 jmp open1
1: 1:
jms access jms access " here if not found
lac u.ac " get access bits from user AC (zero for lock!) lac u.ac " get access bits from user AC (zero for lock!)
and o17 " mask to permissions and o17 " mask to permissions
jms icreat jms icreat
@@ -254,30 +268,30 @@ open1: " common exit for open/creat
"** 01-s1.pdf page 11 "** 01-s1.pdf page 11
.close: .close:
jms finac jms finac " get fnode (open file)
dzm f.flags dzm f.flags " clear flags
jms fput jms fput " write fnode back to u.ofiles
jmp sysexit jmp sysexit
.read: .read:
jms arg jms arg " get argument
and o17777 and o17777 " mask to address
dac u.base dac u.base " save as I/O base
jms arg jms arg " get second argument
dac u.count dac u.count " save as count
lac u.base lac u.base " get base
jms betwen; o10000; o17777 jms betwen; o10000; o17777 " end inside user memory?
jms error jms error " no: error
tad u.count tad u.count " get end of buffer
jms betwen; u.base; o17777 jms betwen; u.base; o17777 " inside buffer/user memory?
jms error jms error " no: error
dac u.limit dac u.limit " yes: save as I/O limit
1: 1:
jms finac jms finac " get fnode for fd in user AC
lac f.flags lac f.flags " get open file flags
and d1 and d1 " get write bit
sza sza " open for write?
jms error jms error " yes: error
lac i.flags " get inode flags lac i.flags " get inode flags
and o40 " get special file bit and o40 " get special file bit
sna " special? sna " special?
src/sys/s5.s
+25 -16
View File
@@ -17,15 +17,15 @@ dskswap: 0
t = t+1 t = t+1
access: 0 access: 0
lac i.flags lac i.flags " get inode flags
lmq " save in MQ lmq " save in MQ
lac u.uid " get user id lac u.uid " get user id
spa " negative? spa " negative?
jmp access i " yes: super user, return jmp access i " yes: super user, return
sad i.uid " compare to file owner sad i.uid " compare to file owner
lrs 2 " same: shift flags down two lrs 2 " same: shift flags down two
lacq " get flags back lacq " get inode flags back
and mode " mode from system call and mode " AND with mode from system call
sza " access allowed? sza " access allowed?
jmp access i " yes: return jmp access i " yes: return
jms error " no: return error from system call jms error " no: return error from system call
@@ -256,18 +256,24 @@ movdsp: 0
ion ion
jmp movdsp i jmp movdsp i
" fetch user argument from word after "sys" call, return in AC
arg: 0 arg: 0
lac u.rq+8 i lac u.rq+8 i " fetch word after return PC
isz u.rq+8 isz u.rq+8 " bump PC
jmp arg i jmp arg i
" fetch user pathname argument from pointer word after "sys" call
" into "name" and look it up (in current working directory)
" if lookup fails: returns error to user (not caller)
" if lookup OK: returns with file i-inode read (into "inode")
" and i-number in AC
argname: 0 argname: 0
jms arg jms arg " fetch name pointer
dac .+2 dac .+2 " save as copy source
jms copy; ..; name; 4 jms copy; ..; name; 4 " copy to "name"
lac u.cdir lac u.cdir " get CWD
jms namei; name jms namei; name " look up file
jms error jms error " failed: return error directly to user
jmp argname i jmp argname i
seektell: 0 seektell: 0
@@ -288,13 +294,16 @@ seektell: 0
lac f.badd lac f.badd
jmp seektell i jmp seektell i
" system call helper
" fetch system call argument name pointer from after "sys" call
" read inode; if current user is not owner, return error to user
isown: 0 isown: 0
jms argname jms argname
jms iget jms iget
lac u.uid lac u.uid " get user id
sma sma " super user?
sad i.uid sad i.uid " no: does user own file?
skp skp " yes, or super user
jms error jms error " not super user, not owner: return error
jmp isown i jmp isown i
src/sys/s6.s
+19 -18
View File
@@ -43,24 +43,25 @@ t = t+4
" Given a pointer to a 4-word filename after " Given a pointer to a 4-word filename after
" the jms to namei, and with AC holding the " the jms to namei, and with AC holding the
" i-num of the directory it is in, return the " i-num of the directory it is in, return the
" i-number of the filename, or 0 if not found " i-number of the filename (and skip)
" return zero in AC if not found (no skip)
namei: 0 namei: 0
jms iget " Get the inode from the i-num in the AC jms iget " Get the inode from the i-num in the AC
-1 -1
tad namei i tad namei i " get argptr-1
dac 9f+t+1 dac 9f+t+1 " save in t1
isz namei isz namei " skip over argument
lac i.flags lac i.flags
and o20 " Is this a directory? and o20 " get directory bit
sna sna " Is this a directory?
jmp namei i " No, loop back jmp namei i " no: return without skip
-8 -8
tad i.size " Subtract 8 from the file's size tad i.size " Subtract 8 from the file's size
cma cma
lrss 3 lrss 3
dac 9f+t dac 9f+t " negative count of directory entries in t0
sna sna " any?
jmp namei i jmp namei i " no: return without skip
dzm di " Store zero in di dzm di " Store zero in di
1: 1:
lac di lac di
@@ -68,10 +69,10 @@ namei: 0
"** 01-s1.pdf page 35 "** 01-s1.pdf page 35
jms dget " Get a directory entry from the dirblock jms dget " Get a directory entry from the dirblock
lac d.i lac d.i " get i-num
sna sna " in use?
jmp 2f jmp 2f " no
lac 9f+t+1 lac 9f+t+1 " get argptr-1
dac 8 dac 8
lac d.name " Compare the four words of the filename in the lac d.name " Compare the four words of the filename in the
sad 8 i " directory entry with the argument to namei sad 8 i " directory entry with the argument to namei
@@ -90,13 +91,13 @@ namei: 0
skp skp
jmp 2f " No match jmp 2f " No match
lac d.i " A match. Get the i-number into AC lac d.i " A match. Get the i-number into AC
isz namei " Skip over the argument and return isz namei " give skip return
jmp namei i jmp namei i
2: 2:
isz di " No match, move up to the next direntry isz di " No match, move up to the next direntry
isz 9f+t isz 9f+t " any left?
jmp 1b jmp 1b " yes: keep going
jmp namei i " Didn't find it, return zero in AC jmp namei i " Didn't find it, return zero in AC (without skip)
t = t+2 t = t+2
" Given an i-number in AC, fetch that i-node " Given an i-number in AC, fetch that i-node
" from disk and store it in the inode buffer " from disk and store it in the inode buffer
src/sys/sop.s
+1 -1
View File
@@ -77,7 +77,7 @@ rrb = 0700112 " PTR: clear flag, or read buffer
psf = 0700201 " PTP: skip if flag set psf = 0700201 " PTP: skip if flag set
pcf = 0700202 " PTP: clear flag pcf = 0700202 " PTP: clear flag
psa = 0700204 " PTP: alphanumeric mode psa = 0700204 " PTP: alphanumeric mode
cdf = 0700501 " ??? cdf = 0700501 " G-2: clear display flags
lds = 0701052 " G-2: load display status lds = 0701052 " G-2: load display status
lda = 0701012 " G-2: load display address lda = 0701012 " G-2: load display address
wcga = 0704206 " G-2: ??? wcga = 0704206 " G-2: ???