program secret plane size and position registers described as "reserved"
in g45_vol_3_register_0_0.pdf that was found by inspecting vesa bios
port traces.
also, we have to set 18:19 (Cursor/Dispaly/Overlay Planes Off) in
PIPExCONF while programming the planes on this card. this is what
vesa bios does on modeset.
avoid sync the jar file when fids get clunked.
the only reason to sync the jar on clunk is when it has
been marked dirty (cookies added or deleted) and we
want to flush the changes to disk.
- rewrite when jar->dirty != 0 (caller modified the in memory jar)
- reread when the jar->qid != stat(jar->file)->qid (on disk file changed)
- ignore deleted cookies in cookiesearch()
initially, pio was used to access registers so i didnt need
a kernel driver for initial testing.
pio does not work under efi, so use mmio to access registers.
check that Free.next and Free.prev pointers are not nil.
check that Free.left and Free.right are Poison in non-tree nodes.
check that Free.left and Free.right are *not* Poison in tree nodes.
change Poison to 0xffffffffcafebabe for 64bit machines.
we have to reset hwblank when switching drivers to
prevent the generic vgablank() to be called by
blankscreen().
remove code setting hwblank from vga drivers as
devvga will always force hwblank to be 1 or 0
depending on if the driver provides a native blanking
routine.
set hwaccel to 1 when the driver provides native fill
and scroll routines independent of softscreen being
disabled. this allows hw acceleration to be used when
softscreen gets switched off.
don't hold drawlock duing vga enable and disable, but just zero
the function pointers under drawlock *before* disabling the vga
device.
holding the drawlock while calling out into enable and disable
is not a good idea. with vgavesa, this might deadlock when
userspace realemu tries to print in a rio window with vgavesa.
in 9front, screen blanking is always initiated from process context,
so there is no need for a kproc anymore.
care has been taken for the race between vesadisable() and vesablank()
by acquiering the drawlock prior calling scr->dev->enable() and
scr->dev->disable(). this also has the side effect of accelerated
fills and scrolls not being called during device disable.
Prior to switching display, switch to text mode 3, which
is supported by anything, then set display, search for the
desired mode, load it if found. If not found, set the display
to the old one and switch to the old mode back.
