Make rtems_initialize_data_structures(),
rtems_initialize_before_drivers() and rtems_initialize_device_drivers()
static. Rename rtems_initialize_start_multitasking() to
rtems_initialize_executive() and call the registered system
initialization handlers in this function. Add system initialization API
available via #include <rtems/sysinit.h>. Update the documentation
accordingly.
This is no functional change, only the method to call the existing
initialization routines changes. Instead of direct function calls a
table of function pointers contained in the new RTEMS system
initialization linker set is used. This table looks like this (the
actual addresses depend on the target).
nm *.exe | grep _Linker | sort
0201a2d0 D _Linker_set__Sysinit_begin
0201a2d0 D _Linker_set__Sysinit_bsp_work_area_initialize
0201a2d4 D _Linker_set__Sysinit_bsp_start
0201a2d8 D _Linker_set__Sysinit_rtems_initialize_data_structures
0201a2dc D _Linker_set__Sysinit_bsp_libc_init
0201a2e0 D _Linker_set__Sysinit_rtems_initialize_before_drivers
0201a2e4 D _Linker_set__Sysinit_bsp_predriver_hook
0201a2e8 D _Linker_set__Sysinit_rtems_initialize_device_drivers
0201a2ec D _Linker_set__Sysinit_bsp_postdriver_hook
0201a2f0 D _Linker_set__Sysinit_end
Add test sptests/spsysinit01.
Update #2408.
According to the C11 and C++11 memory models only a read-modify-write
operation guarantees that we read the last value written in modification
order. Avoid the sequential consistent thread fence and instead use the
inter-processor interrupt to set the thread dispatch necessary
indicator.
This mutex implementation uses a thread priority queue with a simple
priority inheritance mechanism (similar to the object based mutexes).
The storage space must be supplied by the user (16 bytes on 32-bit
targets).
Move the storage for the thread queue heads to the threads. Each thread
provides a set of thread queue heads allocated from a dedicated memory
pool. In case a thread blocks on a queue, then it lends its heads to
the queue. In case the thread unblocks, then it takes a free set of
threads from the queue. Since a thread can block on at most one queue
this works. This mechanism is used in FreeBSD. The motivation for this
change is to reduce the memory demands of the synchronization objects.
On a 32-bit uni-processor configuration the Thread_queue_Control size is
now 8 bytes, compared to 64 bytes in RTEMS 4.10 (other changes reduced
the size as well).
Separate the thread queue heads and lock from the operations. This
enables the support for light weight objects which only support one
queuing discipline.
Add rtems_interrupt_local_disable|enable() as suggested by Pavel Pisa to
emphasize that interrupts are only disabled on the current processor.
Do not define the rtems_interrupt_disable|enable|flash() macros and
functions on SMP configurations since they don't ensure system wide
mutual exclusion.
This was obsolete and broken based upon recent time keeping changes.
Thie build option was previously enabled by adding
USE_TICKS_FOR_STATISTICS=1 to the configure command line.
This propagated into the code as preprocessor conditionals
using the __RTEMS_USE_TICKS_FOR_STATISTICS__ conditional.
