Softdevice Update Procedure

[Torsten Robitzki]

Hello,

For the softdevice update, is it the responsibility of the bootloader to make sure, that the softdevice was copied correctly?

If for example the bootloader calls sd_mbr_command() and the device powers down during that copy operations. Is it's up to the bootloader to restart / complete the copy action or will the MBR take care of it (like I hope it does when copying a bootloader)?

The reason, why I ask is because I try to copy the SD with a single call to sd_mbr_command() and it looks like, I end up with a few kByte of SD missing at the beginning, which leads to a bootloader that crashes when it tries to start the SD.

This are the parameters, I use to call the sd_mbr_command():

(gdb) p/x copy_sd_command
$1 = {command = 0x1, params = {copy_sd = {src = 0x23000, dst = 0x1000, len = 0x8800}, compare = {ptr1 = 0x23000, ptr2 = 0x1000, len = 0x8800}, copy_bl = {
  bl_src = 0x23000, bl_len = 0x1000}, base_set = {address = 0x23000}, irq_forward_address_set = {address = 0x23000}}}

If it is the responsibility of the bootloader, to make sure, the SD gets copied correctly, what is the purpose of the MBR command, to copy the SD then?

I think I've overlooked something obvious (again).

Kind regards and thanks in advance,

Torsten

[Hung Bui]

Hi Torsten,

We use the MBR to copy the softdevice because the softdevice +MBR area can be protected and requires the flash operation to be called from inside the protected area, not from the bootloader.

The SD_MBR_COMMAND_COPY_SD will do an erase, then write the new softdevice and then do a memcmp() to check, before returning NRF_SUCCESS or NRF_ERROR_INTERNAL.

So it's the responsibility of the bootloader to check if the call with SD_MBR_COMMAND_COPY_SD return with NRF_SUCCESS or not before moving to the next step.

[Torsten Robitzki]

Thanks a lot; that makes perfect sense!