Update MTS_DRAGONFLY_F411RE bootloader to work with mbed 5 & 6

[felser]

Summary of changes

Update the MTS_DRAGONFLY_F411RE bootloader so it works with mbed version 6.x.

Impact of changes

Migration actions required

Documentation

None

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Pull request type

[X] Patch update (Bug fix / Target update / Docs update / Test update / Refactor)
[] Feature update (New feature / Functionality change / New API)
[] Major update (Breaking change E.g. Return code change / API behaviour change)

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Test results

[] No Tests required for this change (E.g docs only update)
[] Covered by existing mbed-os tests (Greentea or Unittest)
[X] Tests / results supplied as part of this PR

Tested with mbed 5 and 6 as well as with setting MBED-OS_DIR to point to mbed-os branch 'tools-release-6.0.0' from a directory with mbed-os-5.15.1.

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Reviewers

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[ciarmcom]

@felser, thank you for your changes.
@ARMmbed/mbed-os-tools @ARMmbed/mbed-os-maintainers please review.

[adbridge]

@felser I'm a little confused here, is this for Mbed 6 or for Mbed 5? Mbed 5 is only supported on the mbed-os-5.15 branch, so if you need an update for that you would have to raise a separate PR against that branch...

[felser]

The mention of mbed 5 is due to the issue we discovered with our mdot device. When using the online compiler, the mbed 6 tools are used even when an mbed 5 application is being built. This only is for mbed 6.

[maclobdell]

@felser - I don't think bootloaders should live in Mbed OS anymore. Can you refactor your target support such that it is not a requirement for the device to boot up? and a bootloader for FOTA such as with Pelion device management can be added in an application example using the managed bootloader support in Mbed OS. Does that make sense to do?

[felser]

PR #13301 removes the binary hook so mbed_app.json can be used but removal of it caused a problem with the online compiler. Taylor Heck had to add it back in on the mdot. See PR #13135.

[felser]

Can we get this bootloader updated? If you really do not want it in mbed, there needs to be a solution to the online compiler problem when building mbed 5 apps.

[maclobdell]

I see now that this PR is similar to #13135, which added back a bootloader. Can this be merged to resolve the issue in a similar way?

[0xc0170]

CI started

[mbed-ci]

Test run: SUCCESS

Summary: 6 of 6 test jobs passed
Build number : 1
Build artifacts