Add support for Unmanaged Bootloader

[theotherjimmy]

Description

This allows a user to build a completely customized bootloader configuration.

The new configuration options are:

• target.mbed_app_start: The start address of the application
• target.mbed_app_size: The size of the application

When elided, the defaults are:

• target.mbed_app_start defaults to the start of ROM
• target.mbed_app_size defaults to the remaining ROM from the start of the application

Checks are performed to verify that:

• target.mbed_app_start is a location in ROM
• target.mbed_app_size + target.mbed_app_start is also a location in ROM or 1 byte past the end of ROM

Tests

• Manual verification that boot loader still works
• Manual verification that mbed_app_start and mbed_app_size change the apps start
  and size, respectively
• Manually verify that boot loader and mbed_app_* are mutually exclusive
• /morph test
• Documentation

[theotherjimmy]

CC and Review

• @sg-
• @c1728p9
• @LiyouZhou

[theotherjimmy]

/morph test

[mbed-bot]

Result: FAILURE

Your command has finished executing! Here's what you wrote!

/morph test

[0xc0170]

/morph test

[0xc0170]

retest uvisor

[mbed-bot]

Result: SUCCESS

Your command has finished executing! Here's what you wrote!

/morph test

Output

mbed Build Number: 45

All builds and test passed!

[LiyouZhou]

This could be useful. Thx.

[0xc0170]

@theotherjimmy Still underdevelopment (was updated but no mention here why and what has changed) ?

[theotherjimmy]

@0xc0170 I changed the names of things after some productive bikeshedding and talking to a partner engineer offline. I should have informed the PR of what happened.

Let's re-run testing, and then we should be good.
/morph test

[mbed-bot]

Result: SUCCESS

Your command has finished executing! Here's what you wrote!

/morph test

Output

mbed Build Number: 64

All builds and test passed!

[theotherjimmy]

@marcuschangarm Could you review?

[marcuschangarm]

I'm not familiar enough with the mbed tools system to offer qualified advice.

[theotherjimmy]

@marcuschangarm Could you comment on the usability then?

[adbridge]

@theotherjimmy please rebase

[marcuschangarm]

Just gave it a spin and it works great! Two things:

1. Does the mbed_app_start value get defined anywhere so we can use it in the application?
2. Changing mbed_app_start in the json file does not trigger a full rebuild and *_application.bin is still using the old value.

[theotherjimmy]

Does the mbed_app_start value get defined anywhere so we can use it in the application?

as APPLICATION_ADDR

Changing mbed_app_start in the json file does not trigger a full rebuild and *_application.bin is still using the old value.

I'll work on that.

[theotherjimmy]

@marcuschangarm I just made all builds link steps depend on their respective mbed_app.json files. That should fix the dependency issue with both this style bootloader and other config issues.

[marcuschangarm]

Hmm...I don't get a rebuild when I modify the mbed_app.json.

I'm on mbed-cli 1.1.1 and mbed-os bbde379 from your branch.

[theotherjimmy]

@marcuschangarm the dependency only affects the link step. Would you like all c and c++ files depend to the app config?

[marcuschangarm]

@theotherjimmy it seems safest since you are exposing variables like APPLICATION_ADDR to the application.

[theotherjimmy]

I'll get that today

[theotherjimmy]

@marcuschangarm That should do it.

[marcuschangarm]

@theotherjimmy Works great! Thank you very much! 🎉

[theotherjimmy]

Your welcome @marcuschangarm

Looks like I broke some unit tests. Now to update them...

[0xc0170]

/morph test

[mbed-bot]

Result: SUCCESS

Your command has finished executing! Here's what you wrote!

/morph test

Output

mbed Build Number: 220

All builds and test passed!

[marcuschangarm]

Looks like it is ready to ship! 🎉