carl9170fw VS libnklabs

The carl firmware at https://github.com/chunkeey/carl9170fw should put that argument to rest. That is Wifi firmware source code for the Wifi I currently use.

Easily changed likely means there's a physical knob somewhere that you could accidentially poke as a layperson.

Not that you get a three year CS education, figure out how your distribution packages dependencies, install the correct embedded toolchain (good luck), find out exactly which chip is in your device, fetch the proper firmware source code in the right version, build the thing, figure out how to flash the result onto the chip / read the Linux kernel sources to figure out the filename inside /lib/firmware. That's not easy.

Even if this entire process was packaged (it is--see <https://packages.debian.org/sid/firmware-linux-free>), it probably still doesn't count (or at least shouldn't count) as "easily" changed.

There are some cards with open source firmware, you might be able to modify it to do something like that.

https://github.com/chunkeey/carl9170fw/

Two issues with readline: it's GPL and it's big. For embedded systems intended to become products you really need something else. My tiny variant is this, but for sure there are many others:

https://github.com/nklabs/libnklabs

("nkreadline" has editing, tab-completion (for embedded "nkcli" commands) and history)

I used RTEMS on Movius Myriad vision CPU (running on LEON- a SPARC clone).

I remember the RTEMS event concept was not very good- the events are globally shared. You are better off using semaphores.

>I have realized that for a majority of the embedded software using an RTOS is an overkill

I agree with this. Instead of an OS, we like to use a small framework that provides a CLI, database and UART communications (YMODEM protocol). It's a single stack system that provides a simple work-queue for scheduling future tasks / callbacks, and for interrupt code to schedule non-interrupt code. It works for almost everything as long as you are comfortable programming in an event-driven style.

https://github.com/nklabs/libnklabs

(recently added support for AVR 8-bit processors).

I've extracted the Chromium-EC encryption functions, they are convenient for signing / verifying firmware on other platforms. Chromium-ec is nice for example code like this:

https://github.com/jhallen/rsa-verify

On the other hand, if you are looking for some generic embedded system code all in C, here is our library:

https://github.com/nklabs/libnklabs

I think it's most unique feature is the embedded schema-based database- so you can save things like calibration and configuration information in local flash memory. Recently I've been adding device drivers for all common devices I can find on break-out boards for the Arduino and Raspberry-PI communities.