NRF52810 without softdevice S112

[Aurele]

Hello,

I would like to know if it is possible to not use softdevice because i need more flash for my code. I guess it is possible but when i don't enable softdevice in my code, the app_timer stops working and the power management too. Even if i remove SOFTDEVICE_PRESENT compilation flag, the issue is still present. 

My purpose is to use the FDS with my code (which is already filling 92% of the remaining flash (with S112) and my nrf52810 is not doing any BLE), so that's why i came up with removing the soft device but i would like to keep the main library available (in particular the app_timer since it is used in a library shared with a nrf52832) So, do i need to write my own timer or am i missing something ?

If you have any idea, feel free to share.

Best regards,

Aurélien

[Vidar Berg]

Hello,

You can continue to use the app timer library without the Softdevice, but you need to make sure to start the LF clock (LFCLK clock controller) since it's not being started by the Softdevice anymore. Also, to use FDS without Softdevice you need to switch to the NRF_FSTORAGE_NVMC backend instead of the NRF_FSTORAGE_SD which uses the SD flash APIs.

Best regards,

Vidar

[Aurele]

Hello,

Indeed, i have added "nrf_drv_clock_lfclk_request" in my clock init and my timer is running again. Regarding the FDS, i have added FDS_BACKEND = 1 and nrf_nvmc.c to the compilation tree (since nrf_fstrorage_nvmc does not use nrfx interface) and all seems to work fine.

Thank you very much for your help Vidar Berg and awneil

Regards,

Aurélien

[Vidar Berg]

The MBR is included in the Softdevice hex, but there is also a standalone version of it in  \components\softdevice\mbr\hex\ which you can use together with the UART bootloader. The Softdevice is only required if you need DFU over BLE.

[Aurele]

Oh great, now i'm loading only the MBR and then my application at @0x1000 and it is booting and working fine. One more thing, because i cannot find the answer. How the vector tables is remapped in the application ? (is this by using VTOR register that points on a vector tables in RAM (pointing itself on the right handlers in my application ?)

Edit : does the MBR needs to have reserved RAM. Because i cannot set the full segment of RAM for my application. 

With Softdevice : 

FLASH_START=0x19000

FLASH_SIZE=0x17000

RAM_START=0x200022c8

RAM_SIZE=0x3d38

Without softdevice :

FLASH_START=0x1000

FLASH_SIZE=0x2F000

RAM_START=0x20000000

RAM_SIZE=0x6000

When i don't have softdevice (only MBR) and i set RAM_START at 0x20000000, the application does not start but if i set at 0x20000001 it is booting.

[Aurele]

By removing NO_VTOR_CONFIG from my compilations flags, it seems to solve the issue. Now, i can see that my application vector tables is put in flash (@0x1000) and that my startup file is setting VTOR with 0x1000. So, i thing i'm good now.

[Vidar Berg]

You can use the \examples\peripheral\blinky\pca10040e\mbr\ configuration as a reference to see how you can configure an app to run with the MBR. Note that events will not be routed through the MBR if you set the VTOR register.

You can read more about the MBR in the Softdevice specification here Master boot record and bootloader

[Aurele]

Thx, it helped me a lot. Now, i'm also able to run FreeRTOS on my nrf52810 ! That's perfect ;)