To the basics - Simplest program, flash, resources?

[jondbesp32]

Hello - I'm a novice. I watched https://www.youtube.com/c/BenEater 8-bit computer and now I want to write some assembly for the esp32.

I'm curious if there are resources to learn how to write a very basic set of instructions, flash them to the esp32, and get them executed.

For example, I'd like to setup the minimum chip functionality, check a GPIO for signal, turn on a led, and set a timer to interrupt and turn off the led.

I assume I need to write a couple instructions to a bin file, and copy that bin to flash on the esp32. Which flash? Which instruction does the esp32 begin reading from?

I don't want to use espidf or any other toolset at that high of a level. I just want to put bits on a flash and watch the cpu do something.

Any good resources to do this? Where do I start?

Best
Jon

[ESP_Sprite]

Honestly, the Xtensa architecture underpinning the ESP32 is a bit of an odd beast, and there's no official documentation released by the owners of the arch when it comes to the low-level ISA... if you are going to try assembly, might I suggest grabbing an ESP32C3? That chip has a fancy new RiscV core, and as that architecture is all in the open, you should be able to find lots more information about it.

[bobolink]

If you are interested in going with the ESP32-C3, the README on this product https://github.com/wuxx/nanoESP32-C3 seems to have all the important features.
It was the first one google came up with for me.

[bobolink]

I’m having fun with this tutorial from Western Digital https://youtube.com/playlist?list=PL6no ... rXImHXMuLY
riscv ISA IMC32 like the C3 but more expensive hardware $60
https://www.sifive.com/boards/hifive1-rev-b
Espressif isn’t total left out as they provide wireless with ESP32-solo device.
You can step into the code with visual debugging. I’ve only got gdb/openocd to work with the ESP32-C3 which is tedious. And you need to hack up a USB cable.
The tutorial is for an older version of the board. Just remember to specify the Rev B version to PlatformIO.

Edit: Sorry. The Mouser #: 392-CS-HIFIVEB-01 is out of stock until Feb 2022