robin@medstar.UUCP (Robin Cutshaw) (05/03/85)
Here is the patch for the Xenix kernel hard disk table. Each table
entry consists of 4 int (short) parameters. Entry 0 = # of cylinders,
1 = # of heads, 2 = # of sectors/track, and 3 = write precomp. Note that
the the table as supplied has several differences to those in the ROM BIOS.
Also, there is only space for 13 entries so if you have a drive type 14
you must patch another location and you won't be able to use DOS.
There are three places that will have to be patched, /boot,
/etc/badtrack, and /xenix.
If you have a drive of type 4-8 you will somehow have to patch the
floppy drive kernel /xenix.fd. This will be a trick because adb doesn't come
with this distribution.
The Original Table as supplied (/xenix) :
diskinfo: 306 4 17 128
diskinfo+8.: 615 4 17 300
diskinfo+16.: 615 6 17 300
diskinfo+24.: 915 8 17 512
diskinfo+32.: 410 6 17 256
diskinfo+40.: 462 8 17 256
diskinfo+48.: 492 5 17 256
diskinfo+56.: 900 7 17 -1
diskinfo+64.: 900 15 17 -1
diskinfo+72.: 820 3 17 -1
diskinfo+80.: 855 5 17 -1
diskinfo+88.: 855 7 17 -1
diskinfo+96.: 306 8 17 128
diskinfo+104.: 0 24919 28274 28265 /* DO NOT PATCH THIS!!!!!! */
/********** START of PATCHES ************/
Patch #1 :
First boot XENIX from the installation diskette and do a
full install. Then cp /boot /boot-. (on the fixed disk)
adb -w /boot
$x
3f:1f0f?w 75## (## = number of heads)
$q
Patch #2 :
This patch will patch the disk table in /boot.
adb -w /boot
71:10356/w 940
10364/w 940
10370/w 512
10372/w 615
10374/w 4
10378/w -1
10380/w 462
10382/w 8
10388/w 733
10390/w 5
$q
Patch #3 :
This patches the disk table in /etc/badtrack. (They are for the
whole table minus the extra entry that can't be added).
cp /etc/badtrack /etc/badtrack-
adb -w /etc/badtrack
71:28/w 940
36/w 940
42/w 512
44/w 615
46/w 4
50/w -1
52/w 462
54/w 8
60/w 733
62/w 5
$q
Patch #4 :
Patches to make it equivalent to the ROM BIOS (/xenix):
adb -w /xenix -
diskinfo+24/w 940 /* 915.= 940. */
diskinfo+32/w 940 /* 410.= 940. */
diskinfo+38/w 512 /* 256.= 512. */
diskinfo+40/w 615 /* 462.= 615. */
diskinfo+42/w 4 /* 8.= 4. */
diskinfo+46/w -1 /* 256.= -1. */
diskinfo+48/w 462 /* 492.= 462. */
diskinfo+50/w 8 /* 5.= 8. */
diskinfo+56/w 733 /* 900.= 733. */
diskinfo+58/w 5 /* 7.= 5. */
$q
Patch #5 :
apply patch #4 on floppy disk kernel /xenix.fd
/******** End of Patches **********/
New Table Entries (as patched) :
diskinfo: 306 4 17 128
diskinfo+8.: 615 4 17 300
diskinfo+16.: 615 6 17 300
diskinfo+24.: 940 8 17 512
diskinfo+32.: 940 6 17 512
diskinfo+40.: 615 4 17 -1
diskinfo+48.: 462 8 17 256
diskinfo+56.: 733 5 17 -1
diskinfo+64.: 900 15 17 -1
diskinfo+72.: 820 3 17 -1
diskinfo+80.: 855 5 17 -1
diskinfo+88.: 855 7 17 -1
diskinfo+96.: 306 8 17 128
diskinfo+104.: 0 24919 28274 28265 /* PATCH THIS AND DIE */
Questions, comments, bugs to me...
--
----
Robin Cutshaw
Director of Systems Research, MedSTAR, Inc.
..{akgua,gatech,gacsr}!medstar!robin