How to configure memory areas for Bootloader and App on an nrf51822_xxaa?

[la-ble]

I need to know where and how much memory to allocate for the S110 Soft Device v8.0.0, the DFU Bootloader, and a firmware app. These all aren't playing nicely together with the device memory.

What I believe/want to be true:

Does the Soft Device really need 8 KiB of RAM?

Bootloader Settings (example from software pack, dfu_dual_bank_ble_s110_pca10028 (nRF51 PCA10028)):

Firmware App Settings:

Problem 1. I run out of space when I go to compile and have to reduce my stack usage to 255 B (see this post). I have no idea whether this is safe, or whether it is likely that I'll overflow the stack. Is the assembly in arm_startup_nrf51.s the linker?

Problem 2. When I try to reduce the IRAM1 Start to 0x20002000 and add 0xC00 to the size field, I get alerts in the mobile app along the lines of Error on Receive Firmware Image Message: Operation Failed). This partially stems from my ignorance to the difference between IRAM1 and IRAM2.

Does anyone have settings that will work well together for the nRF51822_xxAA variant and the new S110 SD - v8.0.0? I'm not sure if it makes a difference, but this is currently using silicon revision 2.

[Kevin Lee]

For the bootloader, I was able to use

IROM1: 0x0003C000, 0x3C00
IRAM1: 0x20002000, 0x1F80
IRAM2: 0x20003F80, 0x80, NoInit

I am not sure why the start of IRAM1 is 0x2002C00 in the dfu examples. Maybe someone from Nordic can comment on that.

Using these settings, I am able to use Master Control Panel v3.8.0.7 to update an application image using the nrf51822_xxAA variant (PCA10001 board).

[Stefan Birnir Sverrisson]

I can also confirm that it is working on my side with

IROM1: 0x0003C000, 0x3C00
IRAM1: 0x20002C00, 0x1380
IRAM2: 0x20003F80, 0x80, NoInit

I think the start of IRAM1 for the bootloader is set to 0x20002C00 in SDK 8 in order to be compatible with different stacks, but for S110, it should work equally well with with Kevin's IRAM settings.

[Raj]

Hi, I am using the same chip set and memory configurations. Boot loader is working fine and application is updated through OAD,the application is running fine, But whenever the board is restart it directly entering to boot loader mode,I don't known why the application image is failed while validating after the restart can any one help me. please.

[Stefan Birnir Sverrisson]

@Raj I remember once that my device always started in bootloader mode after reset. The problem was that I had my DFU button configured incorrectly, so that the bootloader thought it was pressed, even though it was not pressed. The device can normally be put into bootloader mode by pressing and holding a configured DFU button while resetting, which is BUTTON_4 on the nRF51-DK if I remember correctly. To see if that is the case, you can try to press the DFU button and see if it starts in application mode. To further investigate what is going on, you can debug the bootloader code, following the instructions given on this thread.