softdevice update

[Matt Barr]

First, many thanks for the great DFU recipe in the latest SDK!

I've ported OTA DFU to the IAR tool chain for both s110 and s310. I can flip back and forth between the two softdevices by updating from a .zip file with softdevice, bootloader and init files specific to the target softdevice. This would seem to be safe with v7.1.0 s110 and v2.0.1 s310 since the MBRs are identical.

I notice one small issue when I read back the programmed softdevice images after DFU. When initially programmed after erase the 16 bytes at 0x0800 are 1-filled, and they remain erased after a normal application-only update. This makes sense because these locations are undefined in the softdevice hex file and should remain erased.

However, after softdevice and bootloader DFU for the s110 I find:

:10080000000000000C120300E6180000FF63000067

and for the s310 I find:

:1008000000000000E0100300E6180000FF63000095

I believe this is an unused portion of the MBR and this is a non-issue. Can anyone confirm this, and also confirm that it is generally safe to update softdevice+bootloader between S110 and S310?

Thanks and Best Regards, Matt

[Matt Barr]

It is probably worth noting that with the s310 there are 0x1f000 bytes available between softdevice and bootloader located at 0x38000. This is sufficient to support a combined bootloader+softdevice update with the s310, but there is not much room for bootloader expansion.

[Hung Bui]

@Matt: Correct. Address 0x800 is the flash page where the MBR uses to store some information when doing softdevice&bootloader swapping. It's fine to have something there when you do a bootloader/softdevice update.

[Hung Bui]

Yes, we are aware of that, and it's a bigger issue with S130 and S120 where there is not enough room for bootloader+softdevice update. We will try to find a solution for that.

[Matt Barr]

Thanks very much for the confirmation.

[Jeff Wormsley]

Could you post your port for other IAR users? I've looked at the bootloader_util_arm.c and bootloader_util_gcc.c files, but am not up to porting that to IAR. Thanks!