- small tweak while here

If this happens the imsg may no longer be usable as there may be queued
messages, but this is a) already the case with the code now, and b)
would be the case if recvmsg() fails anyway, so we can document that -1
from imsg_read() invalidates the struct imsgbuf.
discussed with and ok eric

tested by krw

enlarge bsd.rd filesystem; this in turn causes a cd oflow, so enlarge
cd filesystem.
ok jsing@ deraadt@

ok miod@, deraadt@, todd@.

teach people bad habits!
ok krw@, jmc@, dlg@, thib@

okay deraadt@

"go ahead" kettenis@

console case; ok deraadt@ miod@

ok millert@

it is wrong you still have to change it, but it will be correct 99% of the time
and thus you can simply press enter when tset asks for the terminal type and
be done with it.
This is already the standard for most platforms, but a few had been left
in the dark.
pointed to by and ok deraadt@

kettenis@; ok kettenis@ miod@

since it makes a fairly decent template for fdisk -i.  Change the procedure
that makes the rb600 installation miniroot image to use fdisk -i instead of
dd(1) to create the MBR for the image.  Adjust the miniroot disk type in
/etc/disktab to the slightly different layout that fdisk -i creates.

only the ramdisk entry and a new entry for building rb600 installation
miniroot images.
ok miod@

after the diff was written, I made it similar to the freebsd fix of
the same code; pr6287 ok millert@ guenther@

** it is necessary to update make(1) before building now **

files or directories when applicable.
The inspiration and name of MACHINE_CPU come from NetBSD, although the way to
provide it to Makefiles is completely different.
ok kettenis@

ok miod@

installer to pick it and install it as /bsd when applicable.