Write Protection NVM

RE: Write Protection NVM

JeanMBoones — Tue, 21 Nov 2017 17:29:03 GMT

Thank you.

RE: Write Protection NVM

Sigurd — Tue, 21 Nov 2017 15:15:38 GMT

Hi,

I don't see any good reason why the SoftDevice should not allow you to protect the softdevice area also using sd_flash_protect. But, yes, you can always write to the BPROT register directly in the application before enabling the softdevice to protect any part of flash.

RE: Write Protection NVM

JeanMBoones — Mon, 20 Nov 2017 23:34:12 GMT

Hi Sigurd, could you please answer above question? Thank you.

RE: Write Protection NVM

JeanMBoones — Thu, 16 Nov 2017 22:36:38 GMT

Thanks Sigurd. Looking at the documentation for sd_flash_protect(), it returns an error if you try to protect the SoftDevice. I am curious as to why this is the case? Why does sd_flash_protect() return NRF_ERROR_FORBIDDEN when trying to protect the Softdevice (with the Softdevice enabled)?

Also, what if the SoftDevice is disabled. Can I directly modify the BPROT component to Write Protect the area of NVM covered by the Softdevice? OR can you not Write Protect the SoftDevice at all regardless of whether it is enabled or disabled?

RE: Write Protection NVM

Sigurd — Thu, 16 Nov 2017 10:15:21 GMT

For example, I set page 0 as write protected and then later on I want to set page 5 as write protected. I can do that, right?

Yes, that is possible.

Note: If the SoftDevice is enabled, you have to use the function sd_flash_protect()

RE: Write Protection NVM

JeanMBoones — Thu, 16 Nov 2017 03:09:08 GMT

Thanks. I have another question. Can I set individual blocks (pages) using the BPROT at different points in time and then each block (page) becomes Write Protected until reset. For example, I set page 0 as write protected and then later on I want to set page 5 as write protected. I can do that, right? Or do I only get a single write opportunity to the BPROT component?

RE: Write Protection NVM

Sigurd — Mon, 13 Nov 2017 08:22:20 GMT

From the BPROT Chapter in the Product Specification it is stated that

The only way of clearing protection bits is by resetting the device from any reset source.

A list of reset sources can be found here.