Extend flash size of nRF9160 - single slot application

[Mateusz Gancarczyk]

Hi, we use nRF9160 and SDK 1.7.

in one of our applications, we need more than actually available flash. Now we have ~420kB for application - because we use MCUBoot and dual-slot memory in internal flash. To increase available flash size I want to set a single slot in internal flash and in the next step - set a second slot in the external SPI flash (for the bootloader).

So my question is: How to set a single slot in an internal flash and extend available flash for application?

[Håkon Alseth]

Hi,

 

in one of our applications, we need more than actually available flash. Now we have ~420kB for application - because we use MCUBoot and dual-slot memory in internal flash. To increase available flash size I want to set a single slot in internal flash and in the next step - set a second slot in the external SPI flash (for the bootloader).

So my question is: How to set a single slot in an internal flash and extend available flash for application?

This is a dual slot scenario, just that the second slot is in your external flash.

 

Here's an example with mcuboot + hello_world that shows the bare minimal implementation of a SPI nor device as mcuboot second slot:

hello_world_nrf9160_ext_flash.zip

Note that the pm_static is provided as a reference, and any future updates must match the partition layout of your original project.

 

Kind regards,

Håkon

[Mateusz Gancarczyk]

Thanks for the answer! Yes, You right - it's still dual-slot scenario.
But I've got a problem - I'll try to run your project, but it stuck here:

I use nRF9160-DK (PCA100900.15.0). I spend some time debugging but without any idea.

[Håkon Alseth]

Hi,

 

Mateusz Gancarczyk said:

I use nRF9160-DK (PCA100900.15.0)

My apologies, I should have mentioned that you need to switch in the SPI-flash on the DK.

This is done by programming the nrf52 device (board nrf9160dk_nrf52840) with any simple example (hello_world or a modified blinky (ie: a empty main loop) for instance), with this overlay applied:

/ {
        board-control {
                external_flash_pins_routing: switch-ext-mem-ctrl {
                        compatible = "nordic,nrf9160dk-optional-routing";
                        control-gpios = <&gpio0 19 GPIO_ACTIVE_HIGH>;
                        status = "okay";
                };
        };
};

 

Switch the "PROG/DEBUG" switch to "nrf52" mode, configure and flash the project, then switch it back to nRF91 again.

 

Kind regards,

Håkon