4 May
2008
4 May
'08
2:41 p.m.
I took Brad Parker's suggestion for a simple mount rk0 /usr command,
and modified it as follows:
exit = 1.
write = 4.
mount = 21.
mov $1,r0
sys write; rk0+040020; 8.
sys write; usr+040020; 4.
sys mount; rk0+040020; usr+040020
sys exit
sys exit
rk0: </dev/rk0\0>
usr: </usr\0>
Assemble this with V7 as, to get:
0000000 000407 000050 000000 000000 000074 000000 000000 000000
0000020 012700 000001 104404 040052 000010 104404 040063 000004
0000040 104425 040052 040063 104401 104401 062057 073145 071057
0000060 030153 027400 071565 000162 000000 000000 000000 000002
0000100 000000 000000 000002 000000 000000 000002 000002 000000
0000120 000000 000000 000000 000000 000000 000000 000000 000000
0000140 074145 072151 000000 000000 000001 000001 071167 072151
0000160 000145 000000 000001 000004 067555 067165 000164 000000
0000200 000001 000025 065562 000060 000000 000000 000002 000032
0000220 071565 000162 000000 000000 000002 000043
Now hand-edit the top line with a binary editor to have this:
0000000 000405 000130 000000 000000 000074 000000 010000 010000
This makes it an 0405 executable, and the first 2 instructions become
mov r0,r0, i.e. a NOP.
Copy the a.out into your V1 /tmp directory, and use tools/mktape.py to
rebuild the tape. If you haven't used it before, here is what I did:
tools/mktape.py /usr/local/src/V1/bin/* /usr/local/src/V1/etc/* \
/usr/local/src/V1/tmp/*
Now do tools/assemv7 cold to build a cold kernel, then ./simh.cfg to run it
to make rf0.dsk.
Now run tools/assemv7 with no args to get a warm kernel. Copy rf0.dsk to
rk0.dsk so that you have 2 filesystems. Run ./simh.cfg, login as root,
and you should see /tmp/a.out. Run /tmp/a.out; you should see /dev/rk0
echoed on stdout. I don't know why /usr is not echoed.
Now you can chdir to /usr and do ls -l in there.
Annoyingly, du / only shows / and doesn't traverse into /usr. So I
may have had it working before, but I didn't realise that du was not the
best tool to verify the mount.
Cheers,
Warren