Thanks to:
Debande@smd.ucl.ac.be
James.E.Coby.Jr@cdc.com (James Coby)
bismark@alta.Jpl.Nasa.Gov (Bismark Espinoza)
nadya@bog.ucsd.edu (Nadya Williams)
kpischke@cadence.com (Karlheinz Pischke)
Justin Young <justiny@cluster.engr.subr.edu>
============================================================================
From: nadya@bog.ucsd.edu (Nadya Williams)
The FAQ "subject 5.12 Why don't third-party CD-ROMS work on my sun?" says:
When Sun first decided to add CD-ROM support, there were already a great
number of systems in the field, all of which contained boot proms that
expected to boot from disks with 512 byte sectors. Sun had to decide
between replacing a whole lot of boot proms or finding a way to make a
CDROM act like a disk with 512 byte sectors in order to support it as a
boot device. They chose the latter approach.
Many third party CD-ROM drives use 1024 or 2048-byte sectors, which causes
the SCSI driver to see a "data overrun". When the driver asks for N
"blocks" (which it thinks are 512 bytes each ) it gets more data back than
it expected.
Some CD-ROM drives can be told to use 512 byte sectors by setting a jumper,
cutting a trace, or using a software command (mode select). Details vary
widely, but if you are seeing a data overrun on a third party CD-ROM, then
it is most likely doing 1K or 2K transfers and will need some work to be a
boot device for a Sun.
For more information about third-party CD-ROMS on Suns, consult the
CD-ROM FAQ, which is posted periodically to comp.sys.sun.hardware.
============================================================================
From: kpischke@cadence.com (Karlheinz Pischke)
Take a look at the PIONEER documentation if sectorsize is selectable
from 2048 (usual at PCs) 512 Byte (usual at UNIX boxes).
If it's not selectable change FROM
/*
* define for 512 bytes/sector
*/
#define FIVETWELVE
/*
* set drive to read 2048 bytes per sector (default to 512 bytes/sector)
* #undef FIVETWELVE
*/
TO
/*
* define for 512 bytes/sector
* #define FIVETWELVE
*/
/*
* set drive to read 2048 bytes per sector (default to 512 bytes/sector)
*/
#undef FIVETWELVE
IN /usr/kvm/sys/scsi/targets/srdef.h
Then you have to make a new kernel !!!
============================================================================
Facultad de Ciencias Astronomicas Eduardo A. Suarez
y Geofisicas - UNLP
esuarez@fcaglp.fcaglp.unlp.edu.ar
Paseo del Bosque s/n Tel: +54-21-217308/838810
(1900) La Plata +54-21-526589 (part)
Argentina Fax: +54-21-211761
PGP public key = ftp://ftp.fcaglp.unlp.edu.ar/pub/esuarez/edu.pgp
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"We reject kings, presidents, and voting; we believe in rough consensus and
running code."
Dave Clark
1992
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