From mboxrd@z Thu Jan  1 00:00:00 1970
Date: Sun, 10 Sep 1995 19:11:53 -0400
From: forsyth@plan9.cs.york.ac.uk forsyth@plan9.cs.york.ac.uk
Subject: Cannot boot Plan 9 in my motherboard
Topicbox-Message-UUID: 22de0c86-eac8-11e9-9e20-41e7f4b1d025
Message-ID: <19950910231153.aQF8YXTGJdn8P82S-_D5WnqTD8xzoe1XM8ZdUJqJ0GM@z>

>>as the argument, but the system continued to fail to enlarge the window.

>>	Starting other programs such as mothra gave "Not enough bitmap
>>memory..." (more or less, I haven't written down the messages, sorry).
i completed the fix for part of this today: it's a refinement of a change i had to
make earlier for just the reason given above.  the problem is that on the PC
architecture, the screen dimensions and depth are highly variable within certain limits.
when the /dev/bitblt device is initialised, it allocates three screenfuls
of memory for bitmaps (failing that, a single screenful).  this works on most
machines, but the key variables can be zero (or at least too small) on the PC.
aux/vga sorts nearly everything out, but the memory allocated by /dev/bitblt
after that can be given back to the system for general allocation.  /dev/bitblt
will try to get it back on demand, but it allocates screenfuls,
and internal fragmentation of the kernel's memory pool means it can fail
(even though on my 16Mbyte machine there was over 3Mbytes available in all).

i'll try to post the changes tomorrow.  meanwhile, try adding

kernelpercent=40

to the plan9.ini file; see plan9.ini(8) for details and further explanation.

i find this makes things work as well as can be expected on a 4mbyte terminal.