This patch adapts the previously added Beaglebone PWM code from BBBIO to RTEMS.
This work was done in the context of the Google Summer of Code 2016, and further
patches will follow to improve the code quality and documentation.
The basic data and instruction rage functions should be compatible
for all ARMv4,5,6,7 functions. On the other hand, some functions
are not portable, for example arm_cp15_data_cache_test_and_clean()
and arm_cp15_data_cache_invalidate() for all versions and there
has to be specialized version for newer cores.
arm_cache_l1_properties_for_level uses CCSIDR which is not present
on older chips.
Actual version is only experimental, needs more changes
and problem has been found on RPi1 with dlopen so there seems
to be real problem.
Synchronize each cluster of sections of the same type separately
to support even cases where text and data are allocated from different
areas (for example due allocation from different MPU protection regions).
rtems_cache_instruction_sync_after_code_change is called even to data
sections. Propagation of data only changes should not require cache
maintenance operation on sane SMP mutithread capable systems if barrier
instruction is added but be on safe side even for case where self
modifying code uses data sections initial values etc.
The original ARM architecture wide cache_.h is changed to dummy version
for targets not implementing/enablig cache at all.
The ARM targets equipped by cache should include
appropriate implementation.
Next options are available for now
c/src/lib/libbsp/arm/shared/armv467ar-basic-cache/cache_.h
basic ARM cache integrated on the CPU core directly
which requires only CP15 oparations
c/src/lib/libbsp/arm/shared/arm-l2c-310/cache_.h
support for case where ARM L2C-310 cache controller
is used. It is accessible as mmaped peripheral.
c/src/lib/libbsp/arm/shared/armv7m/include/cache_.h
Cortex-M specific cache support
There is need for unambiguous named and defined cache function
which should be called when code is updated, loaded
or is self-modifying.
There should be function to obtain maximal cache line length
as well. This function can and should be used for allocations
which can be used for data and or code and ensures that
there are no partial cache lines overlaps on start and
end of allocated region.
When HYP mode is detected at startup then setup HYP mode
vectors table (for future extensions) clean exceptions
switching to HYP mode and switch CPU to ARM SVC mode.
BSPs which want to use this support need to include next option
in their configure.ac
RTEMS_BSPOPTS_SET([BSP_START_IN_HYP_SUPPORT],[*],[1])
RTEMS_BSPOPTS_HELP([BSP_START_IN_HYP_SUPPORT], [Support start of BSP in ARM HYP mode])
AM_CONDITIONAL(BSP_START_IN_HYP_SUPPORT,test "$BSP_START_IN_HYP_SUPPORT" = "1")
and need to include next lines in corresponding Makefile.am
if BSP_START_IN_HYP_SUPPORT
libbsp_a_SOURCES += ../shared/startup/bsp-start-in-hyp-support.S
endif
The main reason for inclusion of minimum hypervisor related defines
is that current ARM boards firmware and loaders (U-boot for example)
start loaded operating system kernel in HYP mode to allow it take
control of virtualization (Linux/KVM for example).
Provide the scheduler node to initialize or destroy to the corresponding
operations. This makes it possible to have more than one scheduler node
per thread.
Task priorities are only valid within a scheduler instance. The
rtems_task_set_scheduler() directive moves a task from one scheduler
instance to another using the current priority of the thread. However,
the current task priority of the source scheduler instance is undefined
in the target scheduler instance. Add a third parameter to specify the
priority.
Close#2749.
The ARM and PowerPC interrupt epilogues call _Thread_Dispatch() with
interrupts disabled (counter example: SPARC).
On SMP configurations, since inter-processor interrupts set the thread
dispatch necessary indicator this prevents a thread dispatch
notification in post-switch handlers (which all run with interrupts
disabled).
On all configurations, this is a serious issue for the interrupt
latency.
Update #2751
According to the C11 standard only atomic read-modify-write operations
guarantee that the last value written in modification order is read, see
"7.17.3 Order and consistency". Thus we must use a read-modify-write in
_SMP_Inter_processor_interrupt_handler() to make sure we read an
up-to-date message.
Import the <arpa/inet.h> from current FreeBSD. Necessary due to changes
in <netinet/in.h>. Remove BSD hack from <arpa/inet.h>.
Clean up problems with htonl(). These functions are defined in
<arpa/inet.h>. This lead to some problems because they are defined in
<rtems/endian.h> too. Add NTOHL, ... to
<rtems/rtems_bsdnet_internal.h>.
Import the <netinet/in.h> from current FreeBSD. This allows to build
some current software (e.g. libressl).
Add legacy support like
* prototype for in_cksum(),
* IPPORT_USERRESERVED,
* deprecated IPCTL_RT* defines,
* ip_fw_chk_t and ip_fw_ctl_t,
* ip_nat_... (IP NAT hooks), and
* IP_NAT option for get/setsockopt()
to new <rtems/rtems_netinet_in.h>.
Import the <netdb.h> from current FreeBSD. This allows to build some
current software (e.g. libressl).
Add __h_errno().
Update gethostent_r() API. Linux and FreeBSD use a common API now.
Adapt the RTEMS one to provide the same one.
Match gethostbyname_r() with prototype.
A 32-bit Priority_Control limits the uptime to 49 days with a 1ms clock
tick in case the EDF scheduler is used. Increase it to 64-bit to enable
proper operation of the EDF scheduler,
Close 2173.
