ARM Compiler 6.13 testing revealed linker errors pointing out
conflicting use of `__user_setup_stackheap` and
`__user_initial_stackheap` in some targets. Remove the unwanted
`__user_initial_stackheap` from the targets - the setup is
centralised in the common platform code.
Looking into this, a number of other issues were highlighted
* Almost all targets had `__initial_sp` hardcoded in assembler,
rather than getting it from the scatter file. This was behind
issue #11313. Fix this generally.
* A few targets' `__initial_sp` values did not match the scatter
file layout, in some cases meaning they were overlapping heap
space. They now all use the area reserved in the scatter file.
If any problems are seen, then there is an error in the
scatter file.
* A number of targets were reserving unneeded space for heap and
stack in their startup assembler, on top of the space reserved in
the scatter file, so wasting a few K. A couple were using that
space for the stack, rather than the space in the scatter file.
To clarify expected behaviour:
* Each scatter file contains empty regions `ARM_LIB_HEAP` and
`ARM_LIB_STACK` to reserve space. `ARM_LIB_STACK` is sized
by the macro `MBED_BOOT_STACK_SIZE`, which is set by the tools.
`ARM_LIB_HEAP` is generally the space left over after static
RAM and stack.
* The address of the end of `ARM_LIB_STACK` is written into the
vector table and on reset the CPU sets MSP to that address.
* The common platform code in Mbed OS provides `__user_setup_stackheap`
for the ARM library. The ARM library calls this during startup, and
it calls `__mbed_user_setup_stackheap`.
* The default weak definition of `__mbed_user_setup_stackheap` does not
modify SP, so we remain on the boot stack, and the heap is set to
the region described by `ARM_LIB_HEAP`. If `ARM_LIB_HEAP` doesn't
exist, then the heap is the space from the end of the used data in
`RW_IRAM1` to the start of `ARM_LIB_STACK`.
* Targets can override `__mbed_user_setup_stackheap` if they want.
Currently only Renesas (ARMv7-A class) devices do.
* If microlib is in use, then it doesn't call `__user_setup_stackheap`.
Instead it just finds and uses `ARM_LIB_STACK` and `ARM_LIB_HEAP`
itself.
By default, FLASH_SIZE should be read from HW.
In case this is not the case, we define it here, as the size of FLASH
that is available to the application running on M4.
the flash is shared and split between cortex-M4 that
runs (mbed-os) application and the cortex-M0+ that
runs the BLE firmware.
The 512K allocated to the application was a
conservative that can now be updated.
With recent up-to-date BLE firmware flashed @ 0x080CB000,
there should be 812K available to application.
But there are boards out there that don't have an up-to-date
firmware, so we're keeping an intermediate, safer,
application size of 768K.
Typically the RTC clock is configured by RTC driver itself.
RNG on the other hand is shared with M0+ core and it is expected that
M4 turns it on at boot time.
Review HSE clock initialization to match with latest CUBE firmware.
Also there is no need to set the full clock tree again after deep sleep exit.
With this change we get a stable deep sleep mode (when allowed by CORDIO stack).
There is no need to add FIRST attribute to MAPPING_TABLE as the default
ordering is alphabetical order.
With this change, we don't have any warning with MBED2 and the sections
are properly ordered anyway in BLE cases.
In case of mbed2, BLE feature is not built.
As there is a MAPPING_TABLE in BLE feature which is not compiled in case
of mbed2, the linker reported the below error
[ERROR] "C:/Data/Workspace/mbed/BUILD/test/NUCLEO_WB55RG/ARM/MBED_2/
.link_script.sct", line 65 (column 6): Error: L6236E:
No section matches selector - no section to be FIRST/LAST.
Solution is to check whether BLE is enabled.
- move hw_conf.h file to targets/TARGET_STM/TARGET_STM32WB directory as
this is used also out of BLE feature.
- create a dedicated hal_deepsleep function as the behavior in WB is a lot
different from other existing STM32 targets
- update clock tree configuration to directly clock the entire tree @ 32MHz
out of HSE. This is needed as we want to let the M0 core running without
any change on M0-side of clocks when M4 enters /exits deep sleep.
Martin Kojtal
Kevin Bracey
jeromecoutant
Vincent Veron
Laurent Meunier
bcostm