. don't loop doing a receive() after sendrec() - chance of recovering is not
high, and can lead to receive()ing a notify() (which can't happen in sendrec()),
which is terrible
. return status from device when DEV_CANCEL is done on a signal; hardcode EAGAIN to
become EINTR though
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.
library to the memory driver. Always put output from within TTY directly on
the console. Removed second include of driver.h from tty.c. Made tty_inrepcode
bigger. First step to move PM and FS calls that are not regular (API)
system calls out of callnr.h (renumbered them, and removed them from the
table.c files). Imported the Minix-vmd uname implementation. This provides
a more stable ABI than the current implementation. Added a bit of security
checking. Unfortunately not nearly enough to get a secure system. Fixed a
bug related to the sizes of the programs in the image (in PM patch_mem_chunks).
instead of keeping a running total of enqueued processes
(because somehow the load average was broken)
. added SI_KPROC_TAB to get a copy of kernel process table from PM, for
a top implementation
. fixed arg to sys_nice() to make it an endpoint, not a slot number
. loops checked for PID_FREE
. exit broken down in exit and cleanup functions; when reboot happens,
cleanup is done but not exit (as processes have not actually exited),
this keeps drivers working
. fixed a few uninitialized and unused variables
scripts:
. new packaging system
pm: fixed rebooting by making a copy of the monitor code from the user
process. this is necessary because that process is dead by the time
sys_abort() is called.
also added more info to the "can't reply" panic.
