Re: [9fans] recent plan9.iso on hosted kvm/qemu

[erik quanstrom <quanstro@quanstro.net>]

> I hadn't tried it.  I was under the impression that 9atom was tried by
> the OP of this thread.  My plan today is to go through with the install
> and see what happens.  I'll try your 9load next to see if I can boot
> sans excess options.
> The support guy set up a cron job to update the floppy image from me, so
> I can try lots of different stuff (provided it fits in 1.44MB).

you'll need the 9atom kernel as well.  (or to steal bits from
memory.c.)  i'd forgotten about that.  the dance is that 9load
stashes the e820 information in real mode and after it jumps
to protected mode, formats a config variable with the memory layout.
the kernel then recognizes this config variable and uses
it rather than calling bios.  the format of the variable is
[start end )*, so for example

minooka; whatis e820
e820='0 9c400 100000 cfedeff0 100000000 130000000 '

this machine has 3325mb starting at 1mb, and 768mb
of memory we waste starting at 4gb.

since we can override anything 9load makes up, it's
possible to tell the kernel this has any amout of memory
we wish by adding a like like the following to the plan9.ini

e820=0 9c400 100000 cf000000

obviously, telling the kernel it has memory that it doesn't
will be fatal, but you get the point.  :-)

- erik