Hi,
I'm trying to implement a custom bootloader update on the nRF52840 using SoftDevice s140 and SDK 13.0.0. With my new bootloader staged in a scratch region of flash, I'm trying to use nrf_dfu_mbr_copy_bl() to copy the new bootloader. The relevant code is:
res = nrf_dfu_mbr_compare( bootloader_address, scratchpad_address, update_len );
if ( NRF_SUCCESS != res )
{
res = nrf_dfu_mbr_copy_bl( scratchpad_address, update_len );
}
else
{
scratchpad_erase();
}
What happens is nrf_dfu_mbr_copy_bl() triggers a reset (as expected), but the next time around nrf_dfu_mbr_compare() still returns NRF_ERROR_NULL, and so the device continually calls nrf_dfu_mbr_copy_bl() and resets. Is there some initialization I'm missing? Do I need to disable the SoftDevice before doing this? I'm not using anything else from the DFU module, and I have the bootloader start address and MBR params page programmed into UICR. Any help would be appreciated!
Update 2017/8/7:
As I mentioned in the comments below, the behavior I'm seeing now is rather than constantly resetting, the code gets stuck in nrf_dfu_mbr_copy_bl(). Attaching a debugger I see I'm getting a hard fault. It appears to be a bus fault at address 0x10040013 that is escalated to a hard fault. Stack dump is:
r0 0x20000400
r1 0x000008E5
r2 0x00000579
r3 0x000008C5
r12 0x00000583
lr 0x0000058D
pc 0x00000597
psr 0x00000000
Update 2017/8/8:
I've reproduced the problem with a really simple project: copy_bl_test.zip
