the cachetab just keeps track of recent messages that have not
been called cachefree() on. under some conditions, the fixed
table could overflow (all messages having refs > 0). with a
linked list, overflow becomes non fatal and the algorithm is
simpler to implement.
there isnt much of a point in keep maintaining separate
kernel configurations for terminal and cpu kernels as
the role can be switched with service=cpu boot parameter.
to make stuff cosistent, we will just have one "pc" kernel
and one "pc64" kernel configuration now.
we used to tweak arround in the ICH registers for all intel controllers,
which is wrong, as the 200 series has different magic registes. see
the datasheet:
https://www.intel.com/content/www/us/en/chipsets/200-series-chipset-pch-datasheet-vol-2.html
this caused the clocks to be disabled for the 6th port causing a full
machine lockup touching the 6th port registers.
the next problem was that aiju's bios disabled the unused ports somehow
but didnt clear ther PI bits, so that they would stay in Sbist status even
after a port reset. so the port would get stuck in the Dportreset state
forever. the fix for this was to use a one second timeout for the
port reset procedure.
we used to bind a pipe to /dev/cons and /dev/consctl with some
shared segment hack to pass tty info arround. now we implement
this as a fileserver.
add support for "winchon"/"winchoff" ctl message to enable interrupt
on window size change. (used by ssh)
keep track of fullscreen scrolls, avoiding redrawing the whole
screen each time.
with xhci, bandwidth allocations are handled by the controller
and there are various speed settings possible that currently
not exposed in the Udev. so just keep usbload() as it is for
usb2 and keep ep->load as zero for superspeed.
my pretec usb stick sometimes hangs on the first inquiry request,
waiting for the inquiry response forever. adding a 100ms delay after
the reset command seems to fix it.
getting rid of unused "ding()" note handler and simplify umsrequest()
incomplete read handling.
