by Help! I am working with a cluncky but sentimental old m68k unix
box and have lost some info on how to hack the kernel. Advice,suggestions
and incantations fro System 7 UNIX hackers would be immensely enjoyed if
you are willing to drop me a reply.
The Equipment: 68000 based system
Konan "taisho" smart hard/flopy disk controller board
UniSoft 68000 Unix System 7
The Problem: I would like to add a larger disk drive to my box.
I did this long ago in the past but lost the notebook
that contained details on hacking the unix core image
with adb. I would like it if someone could refresh my
memory or point me in the right direction...
The Technique: I basically remember the jist of how I did it long ago.
I opened up /unix with adb and poked around the symbol
table. Somehow, I got to a table of major/minor device
descriptors. For each minor device entry, there was a
POINTER to another data strcuture that contained device
specific information on the physical disk drive
associated with the major-minor device number. This physical device
descriptor contained information that was loaded into the Taisho Smart
disk
controller board on startup. It contained stuff like # of heads,
write-precomp selection, cylinders, start/end sectors etc.
What I did was to explore this table and look at the device descriptor
for a know drive that was working with the system. Then, I figured out
where the information went, located an unused minor device node and
set its physical descriptor block to match my new drives parameters.
I modified the kernel with adb, rebooted, formatted the new drive and
then used mkfs.. It work fine with no problems.
Now, I'd like to do it again.. But, I forgot the detailes!
The Solution? If anyone could provide me with System 7 standard SYMBOL
table names, data strcture formats and constants used in the generic
disk
driver I would be greatly appreciative.
Thanks. ....... Jim Doyle