Additional free RAM for ESP82266.

[slaff]

RAM is quite limited in ESP8266. The article below explains tricks that can be used to get extra free RAM.

https://blog.attachix.com/get-extra-fre ... n-esp8266/

It should work for both NONOS and FreeRTOS SDKs.

[pratik]

Hello,

A good post!
However, a note to all users doing that - be extremely careful with alignment issues on old compiler versions! If you store a const array of 16-bit (short) type, and directly read it from flash - you will get a fatal exception for misaligned access.
For stuff stored in flash, you must access it with word alignment and in blocks of 4 bytes for reliable program.

[eriksl]

Use readonly strings from flash instead, no hassle with aligning and lots of space to be reclaimed. Just make sure every string is copied to a temporary buffer in RAM before passing the string to os_printf, because these functions count on the strings being in RAM. I have been using this mechanism for over a year and it works like a charm, freeing up lots of RAM.