- -

Framework and the EC

- -

- - Framework - - — for those unaware — is the coolest laptop manufacturer ever. - Their whole shtick is producing laptops that give the - user the ability to easily and effortlessly disassemble, repair, - and modify their hardware. I highly suggest checking them out if - you’re interested in computer hardware at all. The laptops even - have hotswappable I/O! -

- -

- Anyways getting back on topic, Framework has also been giving - power to the user on the software-side of things too! A good - while ago they open-sourced the - - code for the embedded controller - - of their laptops, which offers all sorts of possibilities for - customization of the keyboard, - LED - lights, and more. -

- -

LED Fun!

- -

- This is an area of the - EC - which I have not really looked at or touched much. I do want to - play around with this a lot more in the coming future though! So - far just for shits-and-giggles, I’ve patched the - EC - to make the power-button - LED - green instead of the normal boring white: -

- - - -

- ~/board/hx20/led.c -

m4_fmt_code(led.diff.html)

- - -

- As you can see, it’s all fairly simple. I just had to change our - EC_LED_COLOR_WHITE for - EC_LED_COLOR_GREEN. The codebase defines a few - colors, but they’re defined as RGB - tuples which is awesome, because it opens the door to - custom RGB effects in the future! -

- -

There’s More Than One LED‽

- -

- That’s right! The Framework laptop I own (13″; the 16″ releases - soon though!) has 3 more LED lights. - One on the left of the chassis, one on right of the chassis, and - one on the capslock key. The capslock - LED acts as an indicator of whether or - not you’ve got capslock enabled. This is useless to me though, - because my custom keyboard layout doesn’t even support capslock - (see the next section) — so I patched it to be a function-lock - indicator instead! -

- -

- Here’s the diff — but do take care if you want to apply similar - patches to your laptop! The files I’m editing are under - board/hx20 since I’m on an 11th Gen Intel - CPU. If you have a different - CPU, you will probably need to fuck with - different code: -

- -

- ~/board/hx20/board.h -

m4_fmt_code(fn-lock-1.diff.html)

- - -

- ~/board/hx20/keyboard-customization.c -

m4_fmt_code(fn-lock-2.diff.html)

- - -

- As you can see, toggling the capslock - LED is as simple as - invoking gpio_set_level(). Not only that, but - disabling its functionality with the capslock key is as easy as - undefining the CONFIG_CAPSLOCK_SUPPORT macro. - Figuring out if the function key is locked is also really easy. - The Fn_key global variable is a bit-field containing - information pertaining to the function key, and we also - conveniently already have the FN_LOCKED constant - defined that we can bitwise-AND with Fn_key to check - the locked state! -

- -

- We also setup some hooks with the DECLARE_HOOK() - macro. These just ensure that we are behaving properly on system - resume and -suspend. -

- -

The Hybrid Key

- -

- Wouldn’t it be cool if a physical key could represent two keys at - the same time? I thought so too. Like all Emacs users, I suffer - from a distinct lack of easily-accessible modifier keys. I need - escape because I use Vim bindings; I need left-control because - all the Emacs bindings use it; I need super for my - window-managers’ bindings; I need left-alt so I can type - characters that don’t come on a standard American keyboard (such - as ß, €, and é), and now I have a - problem. All my modifiers are taken, but Emacs still needs a - meta key to work! -

XKCD Comic 1172 — - Workflow by Randall Munroe -

- -

- What will I ever do‽ Well thanks to Framework making - the EC open-source, and conveniently - giving me a file called keyboard_customization.c, - I’m going to take two keys and stick them in one! The basic - premise is this: the capslock key is arguably the easiest - modifier key to hit, and it’s currently bound to the escape key - on my system. This is inefficient though, because nobody makes - key-bindings that chord the escape-key with another key; - chords 1 are always done with a modifier like - control, and Emacs is no different. So my plan was to make it - so that the capslock key when used on its own mimics an - escape-key, while instead mimicking the left-control-key when - used in a chord with another key. -

- -

- It took me a little longer this time to figure out how to - implement what I wanted since the code isn’t as clear, but it was - still a surprisingly easy feature to patch into the - EC! I basically just updated the - scancode table, swapping out the capslock scancode for my own - random one that I called SCANCODE_CTRL_ESC. I then - created a new function called try_ctrl_esc() which - is called in the on-keyup and -down callback function. The - try_ctrl_esc() function handles all of the logic as - you can see in the following diff; it’s basically just a state - machine: -

- - - -

~/board/hx20/keyboard_customization.c

m4_fmt_code(hybrid.diff.html)

- - -

- One thing that’s good to take note of is what I return from - try_ctrl_esc(). The general pattern for handling a - keyup or -down event is to stick the following code into - keyboard_scancode_callback(): -

- -

- keyboard_scancode_callback() in - ~/board/hx20/keyboard_customization.c -

m4_fmt_code(kbd-sc-cb.c.html)

- - -

- In my_handler_function() (or whatever you decide to - name it), you attempt to handle the event. If you don’t want to - handle a particular event and instead want to pass it on to the - next handler, you need to return EC_SUCCESS. If you - managed to successfully handle the event though, then you need to - return an error such as EC_ERROR_UNIMPLEMENTED. - It’s pretty stupid and makes very little sense from a naming - perspective, but oh well… -

- -

What’s Next?

- -

- RGB - LEDs - maybe. -

Framework is Awesome

Table of Contents

Framework and the EC

LED Fun!

There’s More Than One LED‽

The Hybrid Key

What’s Next?