Adding demo bootloader for nrf54L15

[reichel]

I do step-by-step elements from https://academy.nordicsemi.com/courses/nrf-connect-sdk-intermediate/lessons/lesson-9-bootloaders-and-dfu-fota/topic/exercise-5-fota-over-bluetooth-low-energy/

Using LBS sample, NCS 3.1.0, toolchain 3.1.0 and finally  No configure step for 'mcuboot', as mention in sysbuild.conf have only this

SB_CONFIG_BOOTLOADER_MCUBOOT=y

in prj.conf

CONFIG_NCS_SAMPLES_DEFAULTS=y

CONFIG_BT=y

CONFIG_BT_PERIPHERAL=y

CONFIG_BT_DEVICE_NAME="Nordic_LBS"

# Enable the LBS service

CONFIG_BT_LBS=y

CONFIG_BT_LBS_POLL_BUTTON=y

CONFIG_DK_LIBRARY=y

CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=2048

CONFIG_NCS_SAMPLE_MCUMGR_BT_OTA_DFU=y

Not sure what goes wrong (and feel that documentation changes too fast ... too many versions in a short time)

[reichel]

With config nrf54l15dk/nrf54l15/cpuapp build with success

Memory region         Used Size  Region Size  %age Used
           FLASH:       41224 B        54 KB     74.55%
             RAM:       22200 B       188 KB     11.53%
        IDT_LIST:          0 GB        32 KB      0.00%

so, what to do with configuration nrf54l15dk/nrf54l05/cpuap ? What settings should be applied to fit in a memory (error: section `datas' will not fit in reg ion `FLASH').

[Amanda Hsieh]

Hi, 

reichel said:

what to do with configuration nrf54l15dk/nrf54l05/cpuap ?

nRF54l05 has limited internal flash. Please choose another chip with a larger internal flash or use it with an external flash. 

Regards,
Amanda H.

[reichel]

This is really sad. Because even on L10 could not fit if a simple "hello world" takes 74% from L15. This rise cost of the device (especially if this is a simple device). Now, when code development can be quite dynamic (therefore, there is a chance of a bug in the application itself, Zephyr, and also BT stack). Additionally, EU regulations and CRA requirements mean that most clients require the FOTA option (and there will be a chance that it could be obligatory for such devices).

[Amanda Hsieh]

I would suggest you use an external flash for DFU. See this course https://academy.nordicsemi.com/courses/nrf-connect-sdk-intermediate/lessons/lesson-9-bootloaders-and-dfu-fota/topic/exercise-3-dfu-with-external-flash/ 

[reichel]

What benefit (additional component, more space on PCB, emc, ...)? This will also cost and not sure that we can achieve a really lower price, for example for 10k pcs for external 1M flash which will be much more lower then the difference between the price of L05 and L15 ? Must check.

[Amanda Hsieh]

Please contact your regional sales manager for help. 

[reichel]

Yes, I checked the price but booth of us could not belive that we could not fit in smaller version with simple app (know, we have never BT stack, but ...). On nrf52832 I fit with secure bootloader, BT stack much more complicated app, and still have room for new things. So maybe you have some advice on how to configure with the new boot manager/partition , or where is a good description about that (not read about zephyr, rather zephyr+nrf). I see one sample smp_svr, but there is not too much info

[reichel]

what about 

CONFIG_PM_PARTITION_SIZE_MCUBOOT

it looks like could be a solution, but is there any proposes what size should be (if RCSA removed fit in L05 but if I would like ta save any encryption what should I use ?)

[Amanda Hsieh]

It might help, but not a lot.  

MCUboot will partition the device with dual slots, mcuboot_primary, and mcuboot_secondary for BLE DFU and swap images the image from the secondary slot. To update via BLE DFU, the application image cannot be larger than the mcuboot_primary and mcuboot_secondary (they have to be the same size). If you don't want to add an external flash, you could try to optimize the memory footprint. For the LBS sample, you can build with prj_minimal.conf. 

Take a look at this course https://academy.nordicsemi.com/courses/nrf-connect-sdk-intermediate/lessons/lesson-9-bootloaders-and-dfu-fota/   

[reichel]

OK, now I'm deal with pm_static.yml and for test-generated thing which could fit on L10, but have some question

1) On L15 "have" magic from dtsi set to 0x165000 for maximum size of app if config was generated automatically. I see this number in zephyr\dts\vendor\nordic\nrf54l15.dtsi but for cpuflpr and my app is for configuration cpuapp (and PM manager do not allow me to build smaller region) For L05 I see in dts 0x75800 but If I create app without bootloader in partition.yml I've got 0x7d000 (so full 512). Could you explain ?

2) Now (without soft device) there is no common BT stack ? Because simple app is huge and have more than 220kb, so with dual bank, there is no possibility to use mcuboot (any option for single, like in older way ?) Without very hard optimization (maybe should go back to nrf52 ...). Is there any way to use a single bank ?

BTW. VSCode with plugin is very messy, when I change something in pm_static.yml and this fail I could not run a pristine build, sometimes open close of VS helps but in most cases new build helps (but not always appear in VS - you need to open and reopen...)

[reichel]

Not sure why I received  "Cannot upgrade: slots are not compatible",

both partitions have the  same size, only shrink and empty reallocated at the end