- utility for building a tape for use with cold-boot

tools/mktape.py

@@ -0,0 +1,65 @@
+#!/usr/bin/env python
+"""
+Make a tape for 1st ed cold boot.
+
+A sequence of files where each file is started with a metadata block
+and followed by data blocks.  A file with a length of zero indicates
+the end.
+
+metadata:
+    length : word
+    mode : byte
+    uid : byte
+    name : variable length
+"""
+
+import os, sys
+from struct import pack
+
+def pad(d) :
+    "pad to 512-byte boundary"
+    l = len(d)
+    m = ((l + 511) & ~511) - l
+    return d + ("\0" * m)
+
+def sMode(m) :
+    return (
+        ("-","s")[(m & 040) != 0] +
+        ("-","x")[(m & 020) != 0] +
+        ("-","r")[(m & 010) != 0] +
+        ("-","w")[(m & 004) != 0] +
+        ("-","r")[(m & 002) != 0] +
+        ("-","w")[(m & 001) != 0] )
+
+def wrFile(out, fn, d, mode, uid) :
+    "write out file."
+    print sMode(mode), uid, fn
+    meta = pack("HBB", len(d), mode, uid) + fn
+    out.write(pad(meta))
+    out.write(pad(d))
+
+def wrEof(out) :
+    wrFile(out, "", "", 0, 0)
+    
+def copyFile(out, fn) :
+    "copy file from local filesystem to tape."
+    f = file(fn, 'rb')
+    d = f.read()
+    f.close()
+    s = os.stat(fn)
+    mode,uid = s[0] & 0xff, s[4] & 0xff
+    if fn[:len(root)] == root :
+        fn = fn[len(root):]
+    wrFile(out, fn, d, mode, uid)
+
+root = "/tmp/s2/"
+def main() :
+    f = file("tape", "wb")
+    for fn in sys.argv[1:] :
+        copyFile(f, fn)
+    wrEof(f)
+    f.close()
+
+if __name__ == "__main__" :
+    main()
+