def fsLoadBootBlocks(self, hostFilename):
"""Load the boot blocks from the specified file."""
f = open(hostFilename, "rb")
for n in range(rtNumBootBlocks):
self.fsBootBlocks[n] = rt11util.readBlocks(f)
f.close()
def _fsReadHomeBlock(self, f):
"""Parse the home block (block 1)"""
if self.fsVerbose:
print "_fsReadHomeBlock():"
blk = rt11util.readBlocks(f, 1, 1)
# TO DO: Block replacement table, etc.
self.fsPackClustSize = rt11util.rtWord(blk, 0722)
self.fsFirstDirSeg = rt11util.rtWord(blk, 0724)
self.fsSysVersion = rt11util.rtWord(blk, 0726)
self.fsVolumeId = blk[0730:0744]
self.fsOwnerName = blk[0744:0760]
self.fsSystemId = blk[0760:0774]
self.fsFileList = []
self.fsDataBlocks = 0
if (self.fsFirstDirSeg == 0x0000) or (self.fsFirstDirSeg == 0x2020):
# Have seen VAX-11/730 console tapes with spaces or zeros in place of
# fsPackClustSize, fsFirstDirSeg and fsSysVersion.
# So if first dir segment is 0x2020, assume this is such an image
# and assume a hopefully sane default.
self.fsFirstDirSeg = 6
if self.fsVerbose:
print " Overriding bogus fsFirstDirSeg value"
if self.fsVerbose:
print " fsPackClustSize =", self.fsPackClustSize
print " fsFirstDirSeg =", self.fsFirstDirSeg
print " fsSysVersion =", self.fsSysVersion
print " fsVolumeId =", self.fsVolumeId
print " fsOwnerName =", self.fsOwnerName
print " fsSystemId =", self.fsSystemId
def _fsReadDataBlocks(self, f):
"""Read the data blocks from the filesystem."""
for entry in self.fsFileList:
entry.deSetData(rt11util.readBlocks(f, entry.deStart, entry.deLength))
def _fsReadDirSegs(self, f):
"""Parse the directory segments.
Directory segments are 2 blocks long, start at block number
fsFirstDirSeg, and are numbered 1 through 31.
We ignore garbage in unused directory segments."""
if self.fsVerbose:
print "_fsReadDirSegs():"
dsNum = 1
while dsNum > 0:
# Read directory segment, convert to 16-bit words
bnum = self.fsFirstDirSeg + ((dsNum - 1) * 2)
if self.fsVerbose:
print " blocks {:d},{:d}".format(bnum, bnum + 1)
blk = rt11util.readBlocks(f, bnum, 2)
wblk = rt11util.bytesToWords(blk)
# Extract fields from directory segment header
numDs, nextDs, highDs, xBytes, dStart = wblk[:rtDirSegHdrSize]
if self.fsVerbose:
print " numDs =", numDs
print " nextDs =", nextDs
print " highDs =", highDs
print " xBytes =", xBytes
print " dStart =", dStart
rt11util.assertError((xBytes % 2) == 0, "Extra bytes count must be even.")
if dsNum == 1:
# Initialize stuff from first dir segment header
self.fsNumDirSegs = numDs
self.fsExtraWords = xBytes / 2
self.fsDirEntSize = rtDirEntSize + self.fsExtraWords
self.fsDirEntPerSeg = (rtDirSegSize - rtDirSegHdrSize) / self.fsDirEntSize
self.fsDataStart = dStart
else:
# Sanity checks
# Each segment should have matching number of dir segs count in header
rt11util.assertWarn(
numDs == self.fsNumDirSegs, "Number of directory segments changed in segment " + str(dsNum)
)
# Each segment should have matching extra byte count in header
rt11util.assertWarn(
xBytes / 2 == self.fsExtraWords, "Number of extra entry bytes changed in segment " + str(dsNum)
)
# Dir segments should point to contiguous sets of data blocks
rt11util.assertWarn(dStart == dsDataBlock, "Non-contiguous data in directory segment " + str(dsNum))
# Unpack remainder of directory segment into list of
# directory entry tuples.
# This line is so ugly, it ought to be in Perl.
# Don't ask me how it works; I barely understood it when I wrote it.
dsEntries = zip(*[iter(wblk[rtDirSegHdrSize:])] * self.fsDirEntSize)
dsDataBlock = dStart
for dsEntry in dsEntries:
statWord, fn1, fn2, ext, fileLen, jobChan, fileDate = dsEntry[:7]
if statWord & deEEOS:
# End of this directory segment
break
entry = dirEntry(
name=[fn1, fn2, ext],
length=fileLen,
start=dsDataBlock,
status=statWord,
jobchan=jobChan,
date=fileDate,
extra=rt11util.wordsToBytes(dsEntry[7:]),
)
self.fsFileList.append(entry)
self.fsDataBlocks += fileLen
dsDataBlock = dsDataBlock + fileLen
if nextDs > 0:
rt11util.assertWarn(nextDs == dsNum + 1, "Non-sequential directory segments.")
dsNum = nextDs
def _fsReadBootBlocks(self, f):
"""Load the boot blocks"""
self.fsBootBlocks = []
for n in [0] + range(2, rtNumBootBlocks + 1):
self.fsBootBlocks.append(rt11util.readBlocks(f, n, 1))
