Since the FP area pointer is passed by reference in
_CPU_Context_Initialize_fp() the optional FP area adjustment via
_CPU_Context_Fp_start() is superfluous. It is also wrong with respect
to memory management, e.g. pointer passed to _Workspace_Free() may be
not the one returned by _Workspace_Allocate().
Close#1400.
On SMP configurations, it is a fatal error to call blocking operating
system with interrupts disabled, since this prevents delivery of
inter-processor interrupts. This could lead to executing threads which
are not allowed to execute resulting in undefined behaviour.
The ARM Cortex-M port has a similar problem, since the interrupt state
is not a part of the thread context.
Update #2811.
The aim of this file is to encapsulate CPU port implementation details.
This helps to hide implementation details from <rtems.h> which
indirectly includes <rtems/score/cpu.h>.
Only use CPU_Per_CPU_control if it contains at least one filed. In GNU
C empty structures have a size of zero. In C++ structures have a
non-zero size. In case CPU_PER_CPU_CONTROL_SIZE is defined to zero,
then this structure is not used anymore.
The priority bit map can deal with a maximum of 256 priority values
ranging from 0 to 255. Consistently use an unsigned int for
computation, due to the usual integer promotion rules.
Make Priority_bit_map_Word definition architecture-independent and
define it to uint16_t. This was already the case for all architectures
except PowerPC. Adjust the PowerPC bitmap support accordingly.
Rename __log2table into _Bitfield_Leading_zeros since it acually returns
the count of leading zeros of an 8-bit integer. The value for zero is a
bit odd. Provide it unconditionally.
Store the floating-point unit property in the thread control block
regardless of the CPU_HARDWARE_FP and CPU_SOFTWARE_FP settings. Make
sure the floating-point unit is only enabled for the corresponding
multilibs. This helps targets which have a volatile only floating point
context like SPARC for example.
Without the source the error code does not say that much.
Let it be up to the CPU/BSP to determine the error code
reported on fatal shutdown.
This patch does not change the current behaviour, just
adds the option to handle the source of the fatal halt.
Add a CPU counter interface to allow access to a free-running counter.
It is useful to measure short time intervals. This can be used for
example to enable profiling of critical low-level functions.
Add two busy wait functions rtems_counter_delay_ticks() and
rtems_counter_delay_nanoseconds() implemented via the CPU counter.
Use a per-CPU thread dispatch disable level. So instead of one global
thread dispatch disable level we have now one instance per processor.
This is a major performance improvement for SMP. On non-SMP
configurations this may simplifiy the interrupt entry/exit code.
The giant lock is still present, but it is now decoupled from the thread
dispatching in _Thread_Dispatch(), _Thread_Handler(),
_Thread_Restart_self() and the interrupt entry/exit. Access to the
giant lock is now available via _Giant_Acquire() and _Giant_Release().
The giant lock is still implicitly acquired via
_Thread_Dispatch_decrement_disable_level().
The giant lock is only acquired for high-level operations in interrupt
handlers (e.g. release of a semaphore, sending of an event).
As a side-effect this change fixes the lost thread dispatch necessary
indication bug in _Thread_Dispatch().
A per-CPU thread dispatch disable level greatly simplifies the SMP
support for the interrupt entry/exit code since no spin locks have to be
acquired in this area. It is only necessary to get the current
processor index and use this to calculate the address of the own per-CPU
control. This reduces the interrupt latency considerably.
All elements for the interrupt entry/exit code are now part of the
Per_CPU_Control structure: thread dispatch disable level, ISR nest level
and thread dispatch necessary. Nothing else is required (except CPU
port specific stuff like on SPARC).
This commit deletes all RTEMS ChangeLog files. These files have been abandoned
since converting to git version control. The historical data may be recovered
by checking out any commit before this one. Most of the contents of these
ChangeLog files can also be found in the git log.
Two external ChangeLog files, ChangeLog.slac and ChangeLog.zlib, remain.
Add CPU port type CPU_Exception_frame and function
_CPU_Exception_frame_print().
The CPU ports of avr, bfin, h8300, lm32, m32c, m32r, m68k, nios2, sh,
sparc64, and v850 use an empty default implementation of
_CPU_Exception_frame_print().
Add rtems_exception_frame and rtems_exception_frame_print().
Add RTEMS_FATAL_SOURCE_EXCEPTION for CPU exceptions. Use rtems_fatal()
with source RTEMS_FATAL_SOURCE_EXCEPTION in CPU ports of i386, powerpc,
and sparc for unexpected exceptions.
Add third parameter to RTEMS_BSP_CLEANUP_OPTIONS() which controls the
BSP_PRINT_EXCEPTION_CONTEXT define used in the default
bsp_fatal_extension().
Add test sptests/spfatal26.
Add and use new CPU port define CPU_SIZEOF_POINTER. It must be an
integer literal that can be used by the assembler. This value will be
used to calculate offsets of structure members. These offsets will be
used in assembler code.
The size of a pointer is part of the application binary interface (ABI)
and thus independent of the actual programming language. The compiler
will provide defines to determine the current ABI. We use these defines
to select the appropriate CPU_SIZEOF_POINTER value.
Static assertions in the new file "cpukit/score/src/percpuasm.c" will
ensure that the value of CPU_SIZEOF_POINTER is consistent with the
current compiler settings. Also the offset values used by assembler
code are verfied.
Script does what is expected and tries to do it as
smartly as possible.
+ remove occurrences of two blank comment lines
next to each other after Id string line removed.
+ remove entire comment blocks which only exited to
contain CVS Ids
+ If the processing left a blank line at the top of
a file, it was removed.
