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By spaceman
#83783 davydnorris,

I re-read this thread again, since it's an interesting and important subject,
and I wonder about one thing:

Let's say I have a 32Mbit board, and I flash it with AT v1.6.2, with a 512+512 map.
32Mbit=4MB, and 512KB+512KB=1MB,
so this means that my Firmware, with 2 partitions, takes only 1MB, and I have 3MB left free.

Now the question is this:
I use the Espressif firmware - SDK+AT,
then can I, using AT Commands, access those 3MB of free Flash memory? (for reading, and writing)

If not, then is it done via wiring? directly to the Flash chip?
(if that's how it's done - wiring to the Flash chip, then it's irrelevant for many people, since most hobbyists buy a ready-made module/board.. only real hardware manufacturers will use that option in that case..)
User avatar
By davydnorris
#83788 I have no idea if the AT flash offers that ability, because I don't use it. The AT flash is one of the very simplest ways to use the ESP8266 - there are at least 6 other ways that I can think of:


The NonOS and RTOS are the two lowest level systems - I'm pretty sure every single one of the other ways is built on top of one or the other of those. The AT flash is built on top of the NonOS, for instance.

Each of the approaches I listed above has functions that let you access the rest of the flash programmatically.
User avatar
By spaceman
davydnorris wrote:The AT flash is built on top of the NonOS, for instance.

Aren't AT and NonOS the same?

For example, in AT v1.7.1, the Firmware's file name is:

But for some reason, on AT v1.6.2, the file name does not include "NonOS" in it:

Something profound has changed between those 2, to make the v1.7.1 "NonOS" while the v1.6.2 isn't?
Last edited by spaceman on Sat Sep 14, 2019 5:07 am, edited 1 time in total.
User avatar
By btidey
#83793 AT and NonOS are not the same thing.

The 6 examples given were the environments in which you can build applications (core, libraries etc.)

AT is a simple application that just translates Serial commands into a basic set of functions. The title has NonOS in its name because that is what it is built on.

Although many devices come pre-installed with a version of the AT application then this sort of demands the use of some other microcontroller to run an application and send AT commands to get wifi operations. I think most people flash the device with some more specific application which in most cases avoids the need for a second microcontroller.