This is required if function or direction is changed by some driver
after start of thread multitasking or in interrupts drivers.
There can be problem with calling GPIO function selection before
data section is initialized. But actual ticket lock implementation
seems to be compatible even with memory initialized to zero oven
on SMP.
Original implementation does only bitwise-or with previous register
value for all functions except IN. Switch from one to other function
would lead to incorrect value.
The current versions of U-boot start kernel/RTEMS application image
with instruction and data caches enabled and it sets exception
base register to new address after its self-relocation.
ldr r0, [r9, #GD_RELOCADDR] /* r0 = gd->relocaddr */
mcr p15, 0, r0, c12, c0, 0 /* Set VBAR */
Included changes in bsp_start_hook_0 restore default state to
allow RTEMS image to run after startup from newer U-boot version
on Raspberry Pi.
Clear interrupt enable registers in interrupt controller
to ensure that RTEMS starts from well defined state.
Added only for evaluation purposes. We have to compare the performance
against the ticket lock on the interesting platforms via
smptests/smplock01.
The following GCC shortcoming affects the MCS lock:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66867
Avoid Giant lock for pthread_getattr_np(), pthread_setschedparam() and
pthread_getschedparam(). Replace POSIX threads scheduler lock with
thread state lock.
Update #2555.
The priority inheritance and ceiling CORE mutexes wrongly used the FIFO
queueing discipline. Delete misleading _CORE_mutex_Is_priority(). Bug
introduced by 1e1a91ed11.
Add test sptests/spmutex01, since no existing uni-processor test covered
the thread priority queueing discipline for CORE mutexes.
Fix the interrupt and stop the spurious interrupt from happening.
The fix moves the EOI to C code and cleans that functionality out
of the asm part of the ISR handler.
The code checks the ISR and IRR registers on the enable.
Only ack the master for a slave IRQ if the slave has no other pending
requests.
Move the gdb stub from the i386 UART code to use the libchip drivers.
Use any ports discovered during the probes.
Add gdb control to the boot command line.
Change the device naming to the full device path, not a partial path.
For example /dev/com1.
