how to set iRom and iRam address

[DYNAMICTOYS]

Hi,

1st time using nRF52840  - EV-BT840 on Keil V5.25.20

I use SDK 1702, reference to example   examples\dfu\secure_bootloader\pca10056_s140_ble

My question is what softdevice should I use? 

is    s140_nrf52840_5.0.0-2.alpha_softdevice.hex  ?

and if under this softdevice, what are the setting of iRAM and iROM start address and size?

Thank you so much!

Martin

[Vidar Berg]

Hi,

SDK v17.0.2 is compatible with s140 v7.2.0 as can be seen from the compatibility matrix here: SDKs and SoftDevices. This Softdevice is also included in the SDK and it can be programmed to the board by using the flash Softdevice target in the Keil project, please refer to the "Running examples that use a SoftDevice" section of the SDK getting started guide for more details.

Softdevice flash target

It's fine to use the project's default IRAM and IROM setting. The default memory layouts for devices that include the bootloader are illustrated here link.

Best regards,

Vidar

[DYNAMICTOYS]

Hi Vidar,

From the example code  SurfBoard_nrf52_SDK_1702\examples\dfu\secure_bootloader\pca10056_s140_ble\arm5_no_packs

it has set iRom as 

0xF8000  size : 0x6000

This size is very small, if I change size to bigger like 0x10000, it will step on MBR area and compile error.

So it is very confused.

From other post like here

https://devzone.nordicsemi.com/f/nordic-q-a/23237/what-is-the-recommended-irom-iram-setup-for-s140-5-0-0-3-alpha

it should set to 0x22000 and size DE000

By this setting, my code can compile but it do not run after download.  Once start debug, it will enter HardFault_handler

So what is the actual setting of iRom and iRam?

Thanks!

Martin

[DYNAMICTOYS]

HI Vadar,

Our application on this nrf52840 need DFU and that is why I choose this example to start from.

But the setting start from 0xF8000 which is bootloader address and size is limited.

So should I select other example to start from?   

But add the DFU function later?   But how? 

Thanks!

Martin

[Vidar Berg]

Hi Martin,

The Bootloader is a complete standalone application with the two main responsibilities being handling of DFUs and validation&booting of the main app. Please take a look at the "Dual-bank and single-bank updates" section of the bootloader documentation for a better illustration of this. Notice how the main application is placed right above the Softdevice (ie bluetooth stack).

DYNAMICTOYS said:

So should I select other example to start from?   

 Yes, support for DFU can be added later. I would generally recommend starting development on the main application first. When you have a working app and is ready DFU support, I recommend you go start with reading this blog post: https://devzone.nordicsemi.com/nordic/short-range-guides/b/software-development-kit/posts/getting-started-with-nordics-secure-dfu-bootloader

Best regards,

Vidar