Nordic BLE: Allow configuration of softdevice parameters

[andrewleech]

Description

Allow configuration (via defines) of some of the key settings for the nordic softdevice.

• CENTRAL_LINK_COUNT
• PERIPHERAL_LINK_COUNT
• gatts_enable_params.attr_tab_size
• common_enable_params.vs_uuid_count
• gatts_enable_params.service_changed

These settings control the range of functionality enabled in the softdevice as well as ram consumption.
In particular, reducing these values is critical to enable usage of 16K nrf51 devices.

The defaults have not been changed so this should not effect existing users.

The values can be adjusted on a per-project basis by target_overrides in mbed_app.json, eg:

{
    "target_overrides": {
        "*": {
            "nordic-ble.central_link_count": 0,
            "nordic-ble.peripheral_link_count": 1,
            "nordic-ble.gatt_attr_tab_size": "0x4A0",
            "nordic-ble.uuid_table_max_entries": 2,
            "nordic-ble.is_srvc_changed_charact_present": 1
        },
}

Note: There are a couple of minor edits to the logging lines in mbed-os/targets/TARGET_NORDIC/TARGET_NRF5/TARGET_SDK11/softdevice/common/softdevice_handler/softdevice_handler.c

These edits were not necessary in any later versions of the SDK.

Status

READY

Migrations

There should be no required changes to end user code.

Related PRs

This is a cleaned up re-submission of #5980

Steps to test or reproduce

Changing the target config values above in defines/config should result in a change of ram requirements.

When adjusting settings it is useful to enable target.nrf_enable_logging as shown above. You will then get a printout on the mbed stdout serial port during softdevice configuration as such:

sd_ble_enable: RAM START at 0x20002ef8
sd_ble_enable: RAM start should be adjusted to 0x20001f18
RAM size should be adjusted to 0x60e8

If the START value is lower than the RAM ORIGIN in the current linker file, the linker file can be copied into your project and edited to set the RAM ORIGIN and LENGTH to the printed values.
The mbed compile command can then have the linker arg set to your local linker file.

Pull request type

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

[andrewleech]

The logging in this PR would do well from #5965 once it's finished

[marcuschangarm]

Thank you for the contribution. I think there are too many things going on at the same time in this PR:

1. Use config system to modify BLE parameters.
2. Nordic SDK logging.

Do you mind splitting it up in two PRs please?

Regarding 1, you should add a new mbed_lib.json file to features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF5x and give it a name like nordic-ble instead of modifying target.json.

Regarding 2, just by skimming the code I'm not sure it will play nice with the current UART implementation? At the end of the day, @donatieng would have to sign off on adding this new feature.

[andrewleech]

Yeah... Once I dropped the linker settings from the previous pr it needed some way to show the user what they needed to do, it just grew from there.

The logging stuff works really well in my testing on both nrf51 and nrf51. It uses the UART defines from the original nrf logging but it doesn't touch the actual uarts, redirecting all logging defines to stdout.

[andrewleech]

Thanks for the suggestion about adding a new mbed_lib.json file,, I've been able to update the ones from SDK14 to suit and move the configuration to a single library def file. Much cleaner than all the changes to targets.json!

I've also separated out the logging stuff to its own PR.

This has all made the changeset dramatically smaller.

[marcuschangarm]

This file should probably live here: https://github.com/ARMmbed/mbed-os/tree/master/features/FEATURE_BLE/targets/TARGET_NORDIC

Since it is BLE specific.

[marcuschangarm]

I love it! Do you mind making the same changes to the NRF52 folder please? https://github.com/ARMmbed/mbed-os/tree/master/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF52

Unfortunately, we haven't consolidated the two implementations yet.

[andrewleech]

I checked the nrf52 ble codebase and I'm pretty sure it doesn't need any changes, these config settings are all for existing defines in the softdevice code (notice I removed the hardcoded copies from nrf52 softdevice lib files)

That's why I put the lib for where I did, because the settings are documented by nordic as softdevice settings and moving it would now mean duplicating the file to both ble folders.

Yeah I was amazed that the settings were already nicely exposed for nfr52, after I'd put so much round and round effort into making this work for nrf51/sdk11.

[marcuschangarm]

That's why I put the lib for where I did, because the settings are documented by nordic as softdevice settings and moving it would now mean duplicating the file to both ble folders.

But the single mbed_lib.json could live in the Nordic top-level folder and be shared by both NRF51 and NRF52: https://github.com/ARMmbed/mbed-os/tree/master/features/FEATURE_BLE/targets/TARGET_NORDIC

[andrewleech]

Ah, sure, yeah that does make sense. I'll change it over when I get in to work.

[pingdan32]

It looks good, I think we can add some more configurations, such as "NRF_SDH_BLE_GATT_MAX_MTU_SIZE=23".
"gatt_max_mtu": { "help": "max mtu value", "macro_name": "NRF_SDH_BLE_GATT_MAX_MTU_SIZE", "value": 23 },

[adbridge]

@marcuschangarm Are you happy with this now?

[marcuschangarm]

Are you happy with this now?

Yep! Ship it! 🚢

[cmonr]

Once rebased, we'll start CI.

[andrewleech]

Ok, rebased

[cmonr]

@andrewleech @pan- Good to go!

[0xc0170]

@andrewleech @pan- Good to go!

Needs rebase, @andrewleech Please do

[cmonr]

@paul-szczepanek-arm @marcuschangarm Mind re-reviewing?

[cmonr]

/morph build

[mbed-ci]

Build : SUCCESS

Build number : 2250
Build artifacts/logs : http://mbed-os.s3-website-eu-west-1.amazonaws.com/?prefix=builds/6860/

Triggering tests

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

[mbed-ci]

Test : SUCCESS

Build number : 2039
Test logs :http://mbed-os-logs.s3-website-us-west-1.amazonaws.com/?prefix=logs/6860/2039

[mbed-ci]

Exporter Build : SUCCESS

Build number : 1875
Build artifacts/logs : http://mbed-os.s3-website-eu-west-1.amazonaws.com/?prefix=builds/exporter/6860/

[0xc0170]

/morph mbed2-build