- Proper releasing of user pmd and pgds when a space is not used.
- Proper releasing of task, space ids.
- At occasions a starting thread gets bogus SPSR, this needs investigating.
- At a very rare occasion arch_setup_new_thread() had a kernel data abort during
register copying from one task to another. Needs investigating.
- Fixed potential concurrency bugs due to preemption being enabled.
- Introduced a new address space structure to better account for
address spaces and page tables.
- Currently executes fine up to forking. Will investigate.
- Scheduler was increasing total priorities only when resuming tasks had 0 ticks.
This caused forked tasks that have parent's share of ticks to finish their jobs,
if these tasks exited quick enough, they would cause the total priorities to deduce
without increasing it in the first place. This is now fixed.
- Also strengthened rq locking, now both queues are locked before touching any.
- Also removed task suspends in irq, this would cause a race condition on ticks and
runqueues, since neither is protected against irqs.
A new scheduler replaces the old one.
- There are no sched_xxx_notify() calls that ask scheduler to change task state.
- Tasks now have priorities and different timeslices.
- One second interval is distributed among processes.
- There are just runnable and expired queues.
- SCHED_GRANULARITY determines a maximum running boundary for tasks.
- Scheduler can now detect a safe point and suspend a task.
Interruptible blocking is implemented.
- Mutexes, waitqueues and ipc are modified to have an interruptible nature.
- Sleep information is stored on the ktcb. (which waitqueue? etc.)
- Fixed do_mmap() so that it returns mapped address, and various bugs.
- A child seems to fork with new setup, but with incorrect return value.
Need to use and test exregs() for fork + clone.
- Shmat searches an unmapped area if input arg is invalid, do_mmap()
should do this.
- Added mutex_trylock()
- Implemented most of exchange_registers()
- thread_control() now needs a lock for operations that can modify thread context.
- thread_start() does not initialise scheduler flags, now done in thread_create.
TODO:
- Fork/clone'ed threads should retain their context in tcb, not syscall stack.
- exchange_registers() calls in userspace need cleaning up.
Added routines that check whether a user pointer is accessible by the kernel,
and if not ask the pager to map-in those pages. I haven't implemented yet the
bit that asks the pager for paging-in.
Changed l4id_t type to integer to recognise negative id values like L4_ANYTHREAD.
Added an extremely simple script that cleans and builds everything in right order.
Increased boot pmds by one:
This is due to the fact that if the 1MB initial allocation area of the kernel is
not 1MB-aligned, it is ought to be mapped from the middle of one MB to next,
which requires 2 pmds.
modified: .gdbinit
modified: README
new file: buildall.sh
modified: include/l4/arch/arm/types.h
modified: include/l4/generic/scheduler.h
modified: loader/kernel.S
modified: loader/main.c
modified: loader/mylink.lds
modified: loader/start.axf.S
modified: src/glue/arm/init.c
modified: src/glue/arm/memory.c
modified: tasks/fs0/src/bdev.c
modified: tasks/mm0/include/kdata.h
modified: tasks/mm0/include/vm_area.h
modified: tasks/mm0/src/init.c
modified: tasks/mm0/src/task.c
modified: tools/ksym_to_lds.py
modified: tools/l4-qemu
