Import sources from 2011-03-30 iso image

1 files changed, 108 insertions, 0 deletions

diff --git a/sys/src/cmd/tapefs/tpfs.c b/sys/src/cmd/tapefs/tpfs.c
new file mode 100755
index 000000000..02079a3ae
--- /dev/null
+++ b/sys/src/cmd/tapefs/tpfs.c
@@ -0,0 +1,108 @@
+#include <u.h>
+#include <libc.h>
+#include "tapefs.h"
+
+/*
+ * File system for tp tapes.  dectape versions have 192
+ * entries, magtape have 496.  This treats the same
+ * by ignoring entries with bad header checksums
+ */
+
+struct tp {
+	unsigned char	name[32];
+	unsigned char	mode[2];
+	unsigned char	uid[1];
+	unsigned char	gid[1];
+	unsigned char	unused[1];
+	unsigned char	size[3];
+	unsigned char	tmod[4];
+	unsigned char	taddress[2];
+	unsigned char	unused2[16];
+	unsigned char	checksum[2];
+} dir[496+8];
+
+char	buffer[8192];
+int	tapefile;
+
+void
+populate(char *name)
+{
+	int i, isabs, badcksum, goodcksum;
+	struct tp *tpp;
+	Fileinf f;
+
+	replete = 1;
+	tapefile = open(name, OREAD);
+	if (tapefile<0)
+		error("Can't open argument file");
+	read(tapefile, dir, sizeof dir);
+	badcksum = goodcksum = 0;
+	for (i=0, tpp=&dir[8]; i<496; i++, tpp++) {
+		unsigned char *sp = (unsigned char *)tpp;
+		int j, cksum = 0;
+		for (j=0; j<32; j++, sp+=2)
+			cksum += sp[0] + (sp[1]<<8);
+		cksum &= 0xFFFF;
+		if (cksum!=0) {
+			badcksum++;
+			continue;
+		}
+		goodcksum++;
+		if (tpp->name[0]=='\0')
+			continue;
+		f.addr = tpp->taddress[0] + (tpp->taddress[1]<<8);
+		if (f.addr==0)
+			continue;
+		f.size = (tpp->size[0]<<16) + (tpp->size[1]<<0) + (tpp->size[2]<<8);
+		f.mdate = (tpp->tmod[2]<<0) + (tpp->tmod[3]<<8)
+		     +(tpp->tmod[0]<<16) + (tpp->tmod[1]<<24);
+		f.mode = tpp->mode[0]&0777;
+		f.uid = tpp->uid[0];
+		f.gid = tpp->gid[0];
+		isabs = tpp->name[0]=='/';
+		f.name = (char *)tpp->name+isabs;
+		poppath(f, 1);
+	}
+	fprint(2, "%d bad checksums, %d good\n", badcksum, goodcksum);
+}
+
+void
+popdir(Ram *r)
+{
+	USED(r);
+}
+
+void
+dotrunc(Ram *r)
+{
+	USED(r);
+}
+
+void
+docreate(Ram *r)
+{
+	USED(r);
+}
+
+char *
+doread(Ram *r, vlong off, long cnt)
+{
+	if (cnt>sizeof(buffer))
+		print("count too big\n");
+	seek(tapefile, 512*r->addr+off, 0);
+	read(tapefile, buffer, cnt);
+	return buffer;
+}
+
+void
+dowrite(Ram *r, char *buf, long off, long cnt)
+{
+	USED(r); USED(buf); USED(off); USED(cnt);
+}
+
+int
+dopermw(Ram *r)
+{
+	USED(r);
+	return 0;
+}