Increasing user flash storage on Nano?

[Heliotopos]

I read the application note on increasing user flash storage here:

http://netburner.com/component/docman/d ... ge?Itemid=

I need to create two sections on the Nano, but it's not mentioned specifically in that document. Is the Nano flash sector size 64kB like the 2MB flash platforms? The memory map for the Nano says the application code region is 0x00004000 to 0x007FFFFF. Assuming the same 64kB sector size, if I did the math right I'd add to sys.ld:

AlphaParamBase 0x007DFFFF
BetaParamBase 0x007EFFFF

...and then limit the memory range to 0x4000 - 0x7DFFFE in NBEclipse. Is that correct?

Thanks

[rnixon]

Why not use the file system?

[roland.ames]

I'm GUESSING that the flash has sector size 8k, because 'system configuration storage' and 'user parameter storage' are both 8k, which implies the sector size is 8k or less.

But you should check with NB, or you can look at the NANO device , find the 8MB SPI flash chip, then look up its datasheet.

I don't have a NANO, but I just did the same exercise with a MOD5441X, to find a sector size of 128k.

[rnixon]

The nano uses spi flash, so I'm not sure what you are trying to do will work since other modules use parallel flash, but agree its best to check with them on that.

[Heliotopos]

Why not use the file system?

I'm porting existing code from a MOD5234. I suspect it was written this way because the filesystem is potentially accessible by users, and there's some mutable data we need to prevent them from inadvertently messing with.

But you should check with NB, or you can look at the NANO device , find the 8MB SPI flash chip, then look up its datasheet.

I couldn't identify it, so I went ahead and posted a ticket with NB.

Thanks

[Heliotopos]

NB support told me that this doesn't work the same way on the Nano because the SPI Flash isn't in the processor's memory map. However, they did suggest trying the NANO54415\EFFS-STD-HTTP example, which lets you treat some of the application region as a persistent file system. Our original MOD5234 code just casted the extern-ed chunk of memory to a struct, so there was a little work to use actual files instead, but so far it seems to be working pretty well.

[rnixon]

Should be just as secure as the user param space too. Its not like linux where there is a file system that runs the OS. The only way a user can access the file system is if you write some code in your app to enable them to do it.