FN-layer remapping is (somewhat) possible using "02 00 00 ??" mappings about nudelta

[WinkelCode]

@WinkelCode This seems promising. I'm comparing dumps from my Air75 and my Air60 and this is plausible. Can I ask you how you've made the association that the physical screenshot key for macOS is at offset 0138 (as that is the offset that contains 02 00 00 0c)?

After I figured out how this "splitting" works, it's fairly straightforward to reference these bindings back and forth. However, at the "very beginning" I found it because in the Windows keymap, it only has a single (non-split) binding to SysRq/Print Screen.

[donn]

I... forgive my confusion but I don't understand how 0240 and 0300 were derived

[WinkelCode]

I... forgive my confusion but I don't understand how 0240 and 0300 were derived

I looked at the macOS keymap and found that Meta+Shift+3 and Meta+Shift+4 are at these offsets.

---

Edit: One other value I tried ended up just being the FN layers for the F1 key.

I previously believed the firmware was translating the function keys into separate keymap entries depending on if the FN key is pressed.

Now I believe that the these 02 ?? ?? ?? bindings are actually responsible for all that and that every key just has one "origin" keymap entry.

Edit 2:

This chunk of empty bindings

02a4  00 00 00 00  -> none
02a8  00 00 00 00  -> none
02ac  00 00 00 00  -> none
02b0  00 00 00 00  -> none
02b4  00 00 00 00  -> none
02b8  00 00 00 00  -> none
02bc  00 00 00 00  -> none
02c0  00 00 00 00  -> none
02c4  00 00 00 00  -> none
02c8  00 00 00 00  -> none
02cc  00 00 00 00  -> none

And it's counterpart:

0364  00 00 00 00  -> none
0368  00 00 00 00  -> none
036c  00 00 00 00  -> none
0370  00 00 00 00  -> none
0374  00 00 00 00  -> none
0378  00 00 00 00  -> none
037c  00 00 00 00  -> none
0380  00 00 00 00  -> none
0384  00 00 00 00  -> none
0388  00 00 00 00  -> none
038c  00 00 00 00  -> none

Might be up for grabs as custom FN layer bindings.

It's no match for QMK, but 12 (including the original screenshot binding) open FN-layer capable slots is quite nice, and will surely be useful to folks.

[WinkelCode]

serialized_keymap_win.txt
serialized_keymap_mac.txt

I had ChatGPT "Advanced Data Analysis" whip these up for me, they are the available slots for FN-layer remapping on the Air96. The // comment is the last byte of 02 00 00 ?? for that slot. I tested it on in the Windows keymap with slots // 2D

Edit: This can also be used to trace back the origin of some keys. We may actually have more slots available than expected, for example the "G" key utilizes an FN-layer for 0E 00 00 11, which may be unused on the Air96.

[gabrielsoldani]

@WinkelCode This seems promising. I'm comparing dumps from my Air75 and my Air60 and this is plausible. Can I ask you how you've made the association that the physical screenshot key for macOS is at offset 0138 (as that is the offset that contains 02 00 00 0c)?