Issue in Background DFU with RBP(Read Back Protection)

RE: Issue in Background DFU with RBP(Read Back Protection)

Hung Bui — Tue, 23 Jun 2020 15:34:32 GMT

Hi Sandip,

Thanks for the information.

The -rbp feature in nrfjprog should only enable APPROTECT feature in the chip. And this shouldn't affect the internal activity on the chip in this case the background DFU and the bootloader activity. APPROTECT only disable the debug access port.

Could you try to test by instead of calling nrfjprog.exe --family NRF52 --rbp ALL you simply do a write into address 0x10001208 (it's the address of the APPROTECT register in UICR) to enable APPROTECT manualy, like this:

nrfjprog --memwr 0x10001208 --val 0x00

After that the chip should locked the same as RBP. Please try to test DFU after that.

If you don't do background DFU but normal DFU would the RBP affect the process ?

Could you describe the modification you made to the bootloader / application to do background DFU ?

RE: Issue in Background DFU with RBP(Read Back Protection)

SciTER Development Team — Tue, 23 Jun 2020 12:32:28 GMT

Hi Hung Bui,

[quote userid="2121" url="~/f/nordic-q-a/62807/issue-in-background-dfu-with-rbp-read-back-protection/256228"]Could you give more information on the Read Back Protection mechanism you used ?[/quote]

Ans: We use following command

nrfjprog.exe --recover -f NRF52
nrfjprog.exe --family NRF52 --chiperase --program nrf52832_SD.hex
nrfjprog.exe --family NRF52 --program nrf52832_BLDR.hex
nrfjprog.exe --family NRF52 --program nrf52832_APP.hex
nrfjprog.exe --family NRF52 --rbp ALL
nrfjprog.exe --reset

[quote userid="2121" url="~/f/nordic-q-a/62807/issue-in-background-dfu-with-rbp-read-back-protection/256228"]We don't really have a module called "RBP" on nRF52840.[/quote]

Q. then what will happen if we use this command "nrfjprog.exe --family NRF52 --rbp ALL"

[quote userid="2121" url="~/f/nordic-q-a/62807/issue-in-background-dfu-with-rbp-read-back-protection/256228"]Could you clarify what you meant by "nordic exe" ? [/quote]

Ans: nordic exe means nrfjprog.exe

Thanks,
Sandip Divani

RE: Issue in Background DFU with RBP(Read Back Protection)

Hung Bui — Mon, 22 Jun 2020 14:05:02 GMT

Hi Sandip,

Could you give more information on the Read Back Protection mechanism you used ? We don't really have a module called "RBP" on nRF52840. Did you mean APPROTECT or ACL (Access Control List) ?

Could you clarify what you meant by "nordic exe" ?