Add mbed-os 5 build support for LPC11C24

[omdathetkan]

Description

Fix support for building LPC11C24.

Based on: https://os.mbed.com/blog/entry/Reducing-memory-usage-by-tuning-RTOS-con/

# .gitignore
rtos/*
features/FEATURE_CLIENT/*
features/FEATURE_COMMON_PAL/*
features/FEATURE_UVISOR/*
features/frameworks/*
features/cellular/*
features/lorawan/*
features/net/*
features/filesystem/*
features/netsocket/*
features/storage/*

Pull request type

[X] Fix
[ ] Refactor
[ ] New target
[ ] Feature
[ ] Breaking change

[0xc0170]

@jorisa Can you share the tests you run (using mbed test)

The change is minimal. what is actually fixing? an error?

[ashok-rao]

@jorisa .. how much RAM/Flash is present on the LPC11C24? Why do you want to remove the RTOS component here (via .mbedignore)? That optimisation needs to happen in the application based on requirements..
If this PR is only adding support for LPC11C24, then the change LGTM in mbed_rtx.h ..

Can you please clarify the need for this PR and also attach greentea logs from all 3 compilers here? Thanks.

[omdathetkan]

All, apologies for the lack of additional information with this pull-request.

The LPC11C24 has 32kB Flash / 8kB RAM. We are porting some projects from mbed2 to the latest mbed-os. By following the advice in the mentioned blog post we removed all rtos dependancies on the application level using mbedignore, making it resemble the classic mbed library. The only error that we ran in to was:

[Error] mbed_boot.c@219,6: #error "no target defined"
[Error] mbed_boot.c@245,55: 'INITIAL_SP' undeclared (first use in this function)
[ERROR] libs\mbed-os\rtos\TARGET_CORTEX\mbed_boot.c:219:6: error: #error "no target defined"
     #error "no target defined"

This value is also defined for TARGET_LPC11U24 which is a very similar part (also 32/8Kb). I don't have the infrastructure to test on all 3 compilers, but I verified that this fixes the error on gcc, and that the application runs as expected.

I amended the pull request to default to hex output, since this is what FlashMagic accepts (for the CAN bootloader).

Let me know if additional information is necessary.

As a separate note, would it be an idea to create a target config to exclude all the rtos stuff? I don't know how many other small targets exists that currently still need need to rely on the old library.

[0xc0170]

I checked LPC11C24 it's not in the release (no 2 or 5 release version label in targets.json file).
The headline Add mbed-os 5 build support for LPC11C24 is misleading - it does not make much sense to add this target to mbed OS 5, does it?

[omdathetkan]

I don't know how you define 'supported'. Currently you cannot build this target with mbed-os, with this fix you can. We use a bunch of targets on mbed5 and would prefer to build everything from the same mbed-os library version. I am happy to change the title to something you find more appropriate.

[0xc0170]

I don't know how you define 'supported'.

release_version in targets.json file for a target defined

We use a bunch of targets on mbed5 and would prefer to build everything from the same mbed-os library version. I am happy to change the title to something you find more appropriate.

Sounds fine to me

[0xc0170]

Just a recheck - hex is supported by target?

[ashok-rao]

with this fix you can.

@0xc0170 , without release_version defined in targets.json for this target, how is it able to build for OS 5? release_version must be defined, correct? Or is it the case that build system takes OS 5 as default even if release_version is not specified?

[omdathetkan]

@0xc0170 hex is supported on LPC11C24,

This is how we invoke the build:

[mbed] Exec "C:\Python27\python.exe -u libs\mbed-os\tools\make.py -D -t GCC_ARM -m LPC11C24 --profile profiles\debug.json --source projects\blinky --source libs\mbed-os --build projects\blinky\build\debug --app-config projects\blinky\mbed_app.json"

I assume it defaults to supporting OS 5.

Again to clarify, this is to allow building both "classic" (rtos-less) applications and os5 applications from the same library code base.

Is there a reason why you would want the classic library at all considering this seems to work fine?

Do I need to do something to run the remaining checks?

[0xc0170]

@0xc0170 , without release_version defined in targets.json for this target, how is it able to build for OS 5? release_version must be defined, correct? Or is it the case that build system takes OS 5 as default even if release_version is not specified?

That specifies if it is released or not (target part of mbed 2 lib for instance or published in the targets supported, etc) - that is my understanding. You can still build locally using tools for instance, as @jorisa is doing.

@jorisa This patch looks fine to fine, will run CI. Out of curiosity, with the footprint this target has - what are you going to run there? I would imagine just having single threaded app and even then its limited?

/morph build

[omdathetkan]

It's for a simple CAN based I/O expander, indeed single thread. We use the ROM CAN bootloader with MagicFlash to load the firmware.
We are migrating to mbed-os 5 on more powerful targets, but we like to run our CI for all our projects on the same version of mbed library/build tools, so this would let us build the "legacy" projects.

[mbed-ci]

Build : SUCCESS

Build number : 1738
Build artifacts/logs : http://mbed-os.s3-website-eu-west-1.amazonaws.com/?prefix=builds/6541/

Triggering tests

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

[mbed-ci]

Exporter Build : SUCCESS

Build number : 1372
Build artifacts/logs : http://mbed-os.s3-website-eu-west-1.amazonaws.com/?prefix=builds/exporter/6541/

[mbed-ci]

Test : SUCCESS

Build number : 1541
Test logs :http://mbed-os-logs.s3-website-us-west-1.amazonaws.com/?prefix=logs/6541/1541

[cmonr]

/morph mbed2-build

[0xc0170]

/morph mbed2-build