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)
Default value for timer/idle thread trustzone identifier is 0, updated
it to 1 to allow threads to access secure functions when timer is secure device.
Systick handler switch to secure/nonsecure issues addressed:
1. Switch to secure/nonsecure context save/restore is based on 6th bit in
LR register, correct the bug (R7 instead of LR was used for decision)
2. Prevent R7 from being corrupted in Sys_ContextSave
3. Branch when non-secure rather than secure
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.
Remove the assert that the tick count of the OS matches the tick
count of the tickless timer as this occurs frequently when
debugging. This is because the function svcRtxKernelResume
only increments the OS's tick count until the next wakeup event
so if the device was halted by a debugger past the next wakeup
event the tick counts will be out of sync.