Add pages for esc1+shift and esc1+ctrl - some UK USB keyboards (Dell) and it seems some
German ones: https://groups.google.com/forum/#!topic/comp.os.plan9/ycok6NTCWCg seem to
generate an esc1 + code scancode combination for the pipe/backslash key. Seems like
overkill to add two whole pages for just two keys, but there again RAM is cheap these days.
Probably should take the changes across to omap/kbd.c (and by extension bcm/kbd.c)
but the changes are trivial.
the image cache should not hold onto the text file channel
when not neccesary. now, the image keeps track of the number
of page cache references in Image.pgref. if the number of
page cache references and Image.ref are equal, this means
all the references to this image are from the page cache.
so no segments are using this image. in that case, we can
close the channel, but keep the Image in the hash table.
when attachimage() finds our image, it will check if Image.c
is nil and reattach the channel to the image before it is
used.
the Image.nocache flag isnt needed anymore.
we now always use the new FXSAVE format in FPsave structure and fpregs
file, converting back and forth in fpx87save() and fpx87restore().
document that fprestore() is a destructive operation now.
change fp register definition in libmach and adapt fpr() acid funciton.
avoid unneccesary copy of fpstate and fpsave in sysfork(). functions
including syscalls do not preserve the fp registers and copying fpstate
from the current process would mean we had to fpsave(&up->fpsave); first.
simply not doing it, new process starts in FPinit state.
this makes sure tcp boot will have ther user /tmp's
the same way as from local cwfs. we used /srv/cwfs
to prevent a deadlock with 9660srv as a root filesystem
which has been fixed now.
avoid double entries in the cache for copen() and properly handle
locking so we wont just give up if we cant lock the Mntcache entry,
but drop the cache lock, qlock the Mntcache entry, and then recheck
the cache.
general cleanup (cdev -> ccache, use eqchantdqid())
