The counters I talk about are not related to esp_timer_get_time().
Also , they do not raise interrupts. These counters are from WiFi block. They are used for TSF and they are not documented.

What they CAN do is to independently count microseconds, with ability to set counters values. So these ...

Some test results:
Filesystem: A TAR file, 12 MiB in size, consisting of 640 entries (of them ~ 20 are directories, the rest are html files)
Hardware: ESP32S3, 16MiB OPI PSRAM, 32MiB FLASH, QUAD, 240MHz CPU clock.
PSRAM is enabled and used by the tarfs (~16000 bytes).
open() call: ~92 microseconds ...

Hello :)

I am developing an immutable (read-only) filesystem for esp32, based on TAR archive file format. I need it for my project (lots of PHP scripts and web-content), but may be someone else can find it useful

It is fast, really fast (26 MiB/sec read ()/ fread () on ESP32S3 DevKit clone in ...

Thanks for the reply!

So if I ran out of free DATA pages it is completely ok to mmap() to the INST pages, just make sure the access is 32-bit only and must be aligned? Thats great news!

Hello,

I'd like to mmap() 5 partitions at one time on ESP32-S3. Total partitions size is 8MiB. Am I correct in assumption that ESP32S3 MMU can manage up to 128*64KiB of mmaped data pages at maximum?

My aim is to mmap() 5 partitions and use them as data arrays. The TOTAL size of all partitions is ...

I am not 100% sure but I would check if this cycles are APB cycles (80MHz).

But in the publicly visible parts of ESP-IDF, I only see the MMU used for Flash/PSRAM mapping

Well, the ESP-IDF is written in a such way.. If you enable all memory protection and address translation then you have to rewrite esp-idf. FreeRTOS does not expect any address translation magic etc..

Hello,

It looks like the hardware supports WiFi channels# >14, however with non-standart frequencies (and bandwidth).
There is nothing about it in the documentation.

Does anyone know anything about that? WiFi hardware v7.48.

There are 4 (four) counters like that above but to use them you have to perform some initialization. Counter #0 (example above) works after boot thanks to ROM code. Once initialized, counters can be read or set by using constants 0x01 and 0x10 above shifted left by [0..3] to select required counter ...

Hello,

I'd like to share some of my findings which may be useful for others. These are specific to ESP32-S3.

Two alternatives to `esp_timer_get_time()`, with ability to set counter value.

This code is written fro Arduino framework fro simplicity but can be easily adopted for ESP-IDF.

MMIO ...