Subject: Re: netbsd on laptops -- what's the experien
To: Ian McDonnell <100116.1125@compuserve.com>
From: Keith Moore <moore@cs.utk.edu>
List: netbsd-users
Date: 06/26/1994 19:57:06
> Has anyone any experience of running netbsd on a laptop?  I have
> taken a bootable floppy to a few stores and attemped to boot it
> using the mach/netbsd bootstrap.  Some boot ok, others load the
> kernel and then hang, others (IBM ThinkPad) don't even recognised
> the boot floppy.

I have NetBSD 0.9 running on my ThinkPad 750.  Several patches
were required, both to the boot block and the kernel (for
keyboard, ps2 mouse, and floppy support), but the result
pretty much works.

(Yes, I want to upgrade to netbsd-current, but I've been pretty busy, 
and of course -current is a moving target.  Sometimes I get a chunk
of free time but I have know way of knowing how to bootstrap -current
at that time...other times someone gets a binary snapshot made and
posts some install instructions and I'm busy then...maybe someday
we will be in sync.)

The problem with the boot block on the 750 is because the bios returns 
36 sectors per track for the 2.88 Mb drive...which is bigger than the
real size of the boot floppy, so it gets an error trying to read the 
19th sector of track 0.  The fix is to read the disk label and get 
the real number of sectors/track from there.

> These laptops have tiny displays, but I thought it might be bareable
> if I could get X11 to run with a full 1M frame buffer and pan about
> with the 640x480 viewport.  I'm trying to get an idea of what LCD
> display chip sets are out there and how/if it's supported by the
> current X11 drivers or whether work is needed to get it running.
> Also use in VGA/SVGA modes with external monitors and build-in
> point device support.

I believe that the tp750 uses the 90c24 chip.  XFree86 doesn't
support it yet, but I think there's a small hack that lets it work.
 
> Another concern is the use of the power management, PCMCIA port
> hooks and I/O & video busses.  Does anyone know anything about
> these?  I imagine the power stuff is just a control/status register
> somewhere.  The PCMCIA peripherals have suspend/resume hooks, which
> I guess enables a driver to completely save and restore the hardware
> state for power down or standby modes.  Some machines have a soft
> 'power' on/off switch, this must be a interrupt or some such input.
> Some have slow clock modes to save power.  I wonder if these features
> have propriatory h/w interfaces which are unified with BIOS s/w
> interfaces, or if there are h/w standards.

I wrote a simple Ethernet driver for IBM's PCMCIA Ethernet card.
I might do more fancy power management eventually...Since most
PCMCIA devices can be taught to look like ISA bus devices once
they're enabled, I'm leaning toward a special PCMCIA device driver 
that allows other drivers to register PCMCIA "callbacks" for 
probing, attach/detach, and power management.
 
> Is there someone out there who's privy to the h/w specs and standards,
> who can advise [a unix hacker at AMI, Phoenix, MS, IBM...]?  

For the ThinkPad 750/755/360, there's a tp750 mailing list:
to subscribe, send mail to tp750-request@cs.utk.edu.
Various members of the list have figured out some things.

Keith Moore 

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