Re: booting NetBSD/vax on real hardware

[Dave McGuire <mcguire%neurotica.com@localhost>]

On 05/25/2014 06:06 PM, Charles Dickman wrote:
> After listen to Holm's travails trying to get NetBSD running on his
> vax stations I did a little experimenting.
> 
> test vax: VAXstation 4000 Model 60 with 104MB RAM
> boot server: Pentium Celeron PC running NetBSD 6.1.3, 100baseTX ethernet
> 
> booting NetBSD-6.1.4 uncompressed kernel (netbsd) from local root disk: 25s
> booting NetBSD-6.1.4 compressed kernel (netbsd.gz) from local root disk: 17m 
> 30s
> 
> $ time gzip -d netbsd.gz
>       11.65 real 6.83 user 1.49 sys
> 
> netbooting NetBSD-6.1.4 Install System compressed
> 
> boot.6.1.4: 21m 30s
> boot.4.0.1: fails
> boot.matt: 2m 3s
> 
> netbooting NetBSD-6.1.4 Install System uncompressed
> 
> boot.6.1.4: 54s
> boot.5.1.2: 58s
> boot.4.0.1: fails
> boot.matt: 60s
> 
> netbooting NetBSD-1.5.3 Install System compressed
> 
> boot.mop.1.5.3: 1m 34s
> boot.6.1.4: 3m 23s
> boot.5.1.2: 3m 27s
> boot.4.0.1: 1m 27s
> boot.3.1.1: fails
> boot.2.1: fails
> boot.matt: fails
> 
> It is interesting how poor the decompression speed is in boot for the
> later releases.
> 
> The boot that I have been using for netbooting for the last 5 years or
> so is boot.matt which I believe was supplied by Matt Thomas when the
> boot included in release was broken. It looks like this was about the
> same time that the decompress code in standalone boot transitioned
> from lib/libz to net/zlib. It is clearly 10 times faster than in
> 6.1.4.
> 
> ftp://ftp.netbsd.org/pub/NetBSD/misc/matt/boot

  Is it possible that the caches are not enabled during the
decompresssion?  That might be tough due to per-implementation
differences, but if there's room in the boot code for that stuff, that'd
make a HUGE difference.

               -Dave

-- 
Dave McGuire, AK4HZ
New Kensington, PA