Added QSPI Initialize Function for Total erase

[mjs513]

Paul - @Defragster

Added a new function for the QSPIFlash, initialize, that does a full media format, guess see this and above: https://forum.pjrc.com/threads/58033-LittleFS-port-to-Teensy-SPIFlash?p=259855&viewfull=1#post259855

Its based on FrankB's eraseChip function and what I also used in spiffs in addition to the basic format command.

You may want to move the LUT60 up to the begin function since its not used anywhere else it seems.

[PaulStoffregen]

I would prefer to add this at the LittleFS base level, using calls to the erase block function (so it's usable on all media types). Do you see any reason why that wouldn't fill the same need as this PR?

[Defragster]

LittleFS base level ... yes would be better. Ideally then there would be the same for SPI and QSPI and Program Flash.

Assuming the first time writes will run faster if used for pushing out a stream of data - like pre-allocating a file on SD.

[PaulStoffregen]

Last night I was thinking about this sort of function when I added the 2nd boolean, so we can know whether the hardware is configured separate from whether the logical filesytem is mounted.

I'm leaning towards a more descriptive name like "eraseAll". The name "initialize" could be mistaken to mean just turning on the hardware. I want a name that clearly communicates you will lose any & all stored data. Any thoughts on that?

[Defragster]

Normally that " lose any & all stored data" comes with Format. On Windows there is a checkbox for 'Quick' that just puts the FS format clean structs in place without spending the time to fully do a byte by byte write of Low Level that "rewrites the magnetic sectors". In either case All data is lost to a 'user'.

When it comes to NOR FLASH that 'low level format' may be useful for what magnetic drives do finding and relocating bad sectors.

That doesn't present a better name - unless lowLevelFormat() sounds good? But it could be needed for the NOR's.

[mjs513]

Yeah - was struggling with initialize as well. What Frank and I both used was "eraseFlashChip" versus "eraseDevice". May along the lines of what @defragster was talking about formatFull vs format, or possibly change from format (what we have now to quickFormat and use format for the proposed initialize function?

[Defragster]

I like making current format >> quickFormat. And having format() be the lowLevel Format.

As you can tell .format() confused me in what is was doing given that is just did a FS struct init - not a format.

[PaulStoffregen]

Ok, lowlevelFormat() it is! https://github.com/PaulStoffregen/LittleFS/commit/b3a4e4e5403238f85854f04f2f992ab2f33f0c52

[Defragster]

That looks cool

[PaulStoffregen]

Yes, quickFormat() is better. https://github.com/PaulStoffregen/LittleFS/commit/79c1f7e122baeac8947481d2390c821f36a24dc6

[Defragster]

Except I see quickFormat is pending an annoucenment ...

[Defragster]

Just a fun note in my download folder I just got :: LittleFS-main (11).zip

[PaulStoffregen]

looks like this can be closed now

[mjs513]

Geez - took a nap and the world changes again :)