Subject: Re: putting functionality in firmware vs OS
To: Todd Whitesel <toddpw@best.com>
From: Parag Patel <parag@cgt.com>
List: tech-kern
Date: 07/30/1998 11:09:18
>Yes, but I2O is presumably documented, so you don't need the BIOS as 
much.

Right, but you still have to ask I2O for the same info that you used to 
ask the BIOS or figured out for yourself.  The device info has to come 
from *somewhere*, yes?


>I would be a lot happier if the PC BIOS could be replaced with a "TINY"
>kernel booting from '/rom'.

Funny you mention this, but this is exactly what we're doing for a 
customer who's building a custom MIPS system.  We have a <32k "minimon" 
(mini-monitor) that's just smart enough to gunzip and launch a binary 
image out of another part of flash.  The second image loaded is 
SmartFirmware.  It then sees the flash device as a virtual BSD disk 
partition, and loads a BSD kernel from another area in flash.  Then we 
net-boot it.


>What takes so long in the device prober anyway? It is timeout loops for
>every device that isn't detected?

Mostly.  Probing ISA devices is the worst of it.  Probing PCI devices 
shouldn't take any time, but probing for SCSI devices does.  Then 
there's all that broken/crappy hardware that you have to work around in 
some fashion or other.

Basically, the Real World sucks, and the best you can hope for is to 
get paid a nice high hourly rate to deal with it.  (I've *got* to have 
my morning tea...)


	-- Parag