* Update scatter file for the ARM toolchain to use 2 region memory model.
The scatter file changes affect the following boards:
* LPC1768, ARCH_PRO, UBLOX_C027, XBED_LPC1768 (LPC1768.sct)
* Remove the TOOLCHAIN_ARM_MICRO directory.
* Remove release_version as not necessary and as the target can also run
Mbed OS 6.
* Remove uARM toolchain in the list of supported toolchains for the target.
* Indicate that the target supports the small ARM toolchain C library.
All targets must implement soft_- and hard_power_on/off() functions which are practically same what onboard_modem_api offered.
These were seen as a duplicate features and therefore we removed this.
All targets involved have been updated to reflect the changes
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.
Instead of user defined symbols in assembly files or C files,
use linker scripts to add heap and stack - this is inconsistent
with ARM std linker scripts
--legacyalign, --no_legacyalign are deprecated from ARMC6 compiler, in order to
remove deprecated flags all linker files (GCC and IAR as well to have uniformity)
should strictly align to 8-byte boundary
Marcelo Salazar
Hugues Kamba
Martin Kojtal
mudassar-ublox
Rajkumar Kanagaraj
Antti Kauppila
Kevin Bracey
int_szyk
Chris Snow
Maciej Bocianski
Wajahat Abbas
Deepika
Russ Butler
Nir Sonnenschein
Ari Parkkila
Przemyslaw Stekiel
David Saada
Cruz Monrreal
thesupershan