For character device i/o, FS does a so-called 'magic' grant to let the
driver copy from or to user space. As this is done in FS address space,
the driver is told to do this in FS address space. The redirection to
the right user process then happens at copy-time in the kernel, using the
FS grant table. This also happens for DEV_READ and DEV_WRITE on block
devices.
For other block device i/o, which happens from/to FS buffers, FS does
a 'direct' grant to its own address space for the driver.
After the i/o returns, this access has to be K-I-L-L-E-D, revoked.
Sometimes this is after a SUSPEND and DEV_REVIVE, in which case the
revoking happens in pipe.c.
This conversion happens in safe_io_conversion() in device.c, called
by dev_io and dev_bio.
FS has to pre-allocate its own space for these grant tables. This happens
in main.c.
enforced. If a call is denied, this will be kprinted. Please report any such
errors, so that I can adjust the mask before returning errors instead of
warnings.
Wrote CMOS driver. All CMOS code from FS has been removed. Currently the
driver only supports get time calls. Set time is left out as an exercise
for the book readers ... startup scripts were updated because the CMOS driver
is needed early on. (IS got same treatment.) Don't forget to run MAKEDEV cmos
in /dev/, otherwise the driver cannot be loaded.
if the boot monitor parameter is set. it also sets a boot monitor
parameter (by talking to the PM) so userland knows it.
. ramdisk copy code made slightly smarter
. various select() prettifications (work in progress)
Added interface to select() for pipes (also named pipes), and select()
stubs for regular files.
Added timer library in FS that select() is the first customer of.
This is unfinished, but committed anyway to get a new release out to
Al and testers.
need /tmp any more since 16MB root device; increase to 3.0.5 to make new
CD with working FXP driver. (not tagged 3.0.5 yet as at driver bios-copy
workaround hasn't been done.)
