Previously a so-called utcb shared page was used for transfering
data between posix services. This was a special shmat/get/dt case
allocating from its own virtual pool. Now the term utcb is renamed
as a shared page and integrated with the shm* handling routines.
Generic l4 threads will use long-ipc and not this method. Posix
services will continue to communicate on a shared page for now.
modified: tasks/libl4/include/l4lib/ipcdefs.h
modified: tasks/libl4/src/init.c
new file: tasks/libposix/init.c
modified: tasks/mm0/include/shm.h
modified: tasks/mm0/include/task.h
deleted: tasks/mm0/include/utcb.h
modified: tasks/mm0/main.c
modified: tasks/mm0/src/boot.c
modified: tasks/mm0/src/clone.c
modified: tasks/mm0/src/execve.c
modified: tasks/mm0/src/exit.c
modified: tasks/mm0/src/init.c
modified: tasks/mm0/src/shm.c
modified: tasks/mm0/src/task.c
deleted: tasks/mm0/src/utcb.c
deleted: tools/l4-qemu
- Updated sleeping paths such that a task is atomically put into
a runqueue and made RUNNABLE, or removed from a runqueue and made SLEEPING.
- Modified vma dropping sources to handle both copy_on_write() and exit() cases
in a common function.
- Added the first infrastructure to have a pager to suspend a task and wait for
suspend completion from the scheduler.
Stopped working on self_spawn() - going to finish clone() syscall first.
Arch-specific clone() library call that does ipc() and cloned child setup.
- Need to finish thread_create() that satisfy clone() necessities. i.e. setting up its stack.
Question: Does the pager (and thus the microkernel) have to explicitly set SP_USR?
Once the call is known to be successful, the library could set it.
This will help when syscalls have long arguments individual
utcbs can be mapped to server tasks and kept mapped in until the
tasks die, as opposed to map requests every time a server task maps
a different utcb at the same virtual address.
The changes have preparation code to also passing the utcb info
through the stack as part of the environment.
To sum up env and arg regions have also been added above the stack and
env region is to be used to pass on the utcb address information at
task startup.
