Adjust heap size on stm32f207

[juhoeskeli]

Description

The board has 128kB of RAM. Currently in mbed-os the RAM usage has increased with cloud client so that on this board the code does not fit with the current heap size. This seems to be ongoing trend that with every release the memory usage grows and the linker files need to be adjusted accordingly. Instead of adjusting the linker files and creating PR it would make sense to allow the application to configure the heap like so:

stm32f207xx.icf:

if (!isdefinedsymbol(MBED_APP_HEAP_SIZE)) {
define symbol size_heap = 0xF000;
} else {
define symbol size_heap = MBED_APP_HEAP_SIZE;
}

This PR does not implement that. I just want to hear what you think how this should be handled, because this will not be the last time adjustments are required.

Pull request type

[ ] Fix
[ ] Refactor
[X] Target update
[ ] Functionality change
[ ] Breaking change

[LMESTM]

@0xc0170 @juhoeskeli the sizing of heap and stack sizes is rather an application dependent thing. How do we want to cope with this in long term ? Could this be considered a Change Request to mbed-os to deal with this constraint ?

[0xc0170]

@0xc0170 @juhoeskeli the sizing of heap and stack sizes is rather an application dependent thing. How do we want to cope with this in long term ? Could this be considered a Change Request to mbed-os to deal with this constraint ?

Yes, stack & heap should. @bulislaw / @SenRamakri please review

[0xc0170]

Related issue: #4067

[juhoeskeli]

A change request sounds reasonable. In the meantime can we go forward with the changes in values?

[juhoeskeli]

To next patch release, please.

[0xc0170]

/morph build

[mbed-ci]

Build : SUCCESS

Build number : 3276
Build artifacts/logs : http://mbed-os.s3-website-eu-west-1.amazonaws.com/?prefix=builds/8252/

Triggering tests

/morph test
/morph export-build
/morph mbed2-build

[mbed-ci]

Exporter Build : SUCCESS

Build number : 2901
Build artifacts/logs : http://mbed-os.s3-website-eu-west-1.amazonaws.com/?prefix=builds/exporter/8252/

[mbed-ci]

Test : SUCCESS

Build number : 3084
Test logs :http://mbed-os-logs.s3-website-us-west-1.amazonaws.com/?prefix=logs/8252/3084