Schedule the next OS tick inside of the ticker interrupt rather than
in the systick interrupt. Scheduling this while the ticker is
dispatching prevents an unnecissary rescheduling since this
rescheduling is done anyway when dispatching is finished.
This is particularly useful for the low power ticker on devices with
LPTICKER_DELAY_TICKS set to a non-zero value. This is because the low
power ticker cannot be reschduled immediately and needs to fall back
onto the microsecond ticker which temporarily locks deep sleep.
Note - the optimization in this commit is made possible by the commit:
"Don't reschedule ticker while dispatching"
1. Define RTX_NO_MULTITHREAD_CLIB to provide Mbed-specific multi-thread support for ARM/ARMC6
2. All overridden _mutex_xxx functions are declared with __USED to avoid excluded by linker
NOTE: Microlib doesn't support multi-thread
Add the OsEventObserver mechanism. A client interested in receiving
notifications on certain OS events can register to receive notifications
with osRegisterForOsEvents. This is useful for clients like the secure
memory allocator, which observes thread switching events in order to
swap in and out different memory allocator objects.
OsEventObserver objects expect a context to be maintained per thread on
their behalf. Add this context to the thread control block and extend
the thread creation functions with the ability to supply a context.
uVisor doesn't set the PSP of the target thread. The RTOS sets the PSP
of the target thread from the target thread's TCB. However, when
interrupts of higher priority than PendSV happen between the call to
uVisor to switch boxes, and the RTOS setting PSP, the uVisor vIRQ
interrupt handler will attempt to use an invalid PSP (the PSP from
before the box and thread switch). This leads to a crash. Make box and
thread switching atomic by disabling interrupts immediately before the
box switching until immediately after the new PSP is set.
CMSIS repo does not support pre-processor defines, hence multiple assembly
files are added for secure/non-secure and floating point tools.
Mbed OS tools support assembly file pre-processing, but the build system
does not support multiple assembly files for each target, hence updating
the assembly files.
mbed OS used older RTX4 version and with osThreadDef accepting only 3
parameters, to preserve compatibility we hardcode the 'instances'
parameter to 1.
(cherry picked from commit 428acae1b2ac15c3ad523e8d40755a9301220822)
Russ Butler
Senthil Ramakrishnan
ccli8
Deepika
Jan Jongboom
Michael Coulter
Vladimir Umek
Russ Butler
Bartek Szatkowski
Cruz Monrreal
Martin Kojtal
Jaeden Amero