Re: [9fans] Writing (new) drivers

Re: [9fans] Writing (new) drivers

[Russ Cox]

> Have you tried that under VMWare?  Not that it would help with driver
> development, but I would think for other kernel work it might be handy.

I've been meaning to, but haven't.  I do run Plan 9 under
VMware, but I need to get some more memory for my laptop
in order to run more VMs.

Russ

Re: [9fans] Writing (new) drivers

[Jack Johnson]

Russ Cox wrote:
> You'll be much happier if you can set up two Plan 9 systems,
> one as a crash box and one to do your development on.

Thanks!

Have you tried that under VMWare?  Not that it would help with driver
development, but I would think for other kernel work it might be handy.

-Jack

Re: [9fans] Writing (new) drivers

[Russ Cox]

You'll be much happier if you can set up two Plan 9 systems,
one as a crash box and one to do your development on.
Connect the two with a serial line and ethernet, and
then you can load kernels over the ether (set up tftpd
and dhcpd on the real machine), boot from your development
machine (man kfscmd, look for listen), type at the crash box
via the serial line (set up consolefs), and run the
debugger over the console (man rdbfs).

It sounds like a bit of effort, and it is, but once you
try it you'll never want to use a less helpful system.
The really nice thing about what I've described is that
the crash box has no real persistent state, so you don't
have to worry about losing your file system, and being
able to keep your editing context while the other machine
reboots is really great.

I still do one-machine kernel development more often
than I'd like, and it's just no fun.

Russ

[9fans] Writing (new) drivers

[Jack Johnson]

I've never written a device driver and my C skills are poor, but device
drivers under Plan 9 seem straightforward and I'm considering taking the
plunge.  I'd love to have a driver for my 3Ware IDE RAID controller:

	http://www.3ware.com/products/pdf/Escalade7500DS6-7.qk.pdf

(By the way, thanks for the newer ghostscript with ps2pdf and pdf2ps!)

The cards are supported under Linux and FreeBSD (and NetBSD too, I
believe), so I think I'll have good references to use to figure out
where to start.  Plus, it behaves as if it were just another SCSI
controller, which should simplify things even further.

Needless to say, I'm a little nervous mucking around with a drive
controller.  Is there anything I should watch out for, other than not
testing it on important data?

-Jack