Reproducible QMK firmware builds for my keyboards using QMix and the vial-qmk fork.
QMix provides two helper functions used here:
fetchQmkFirmware— Fetches a pinned version of a QMK firmware repo and primes it so QMK won't warn or crash during buildbuildQmkFirmware— Builds firmware for a specific keyboard, injecting custom keymap source viasrc/srcMount
This project fetches vial-qmk (QMK fork with Vial support) at a specific commit, then builds each keymap by injecting local source into the firmware tree.
Corne Keyboard — split 3x6 + 3 thumb layout based on Helix, for Kailh Choc v1/v2 switches.
- MCU: RP2040 ProMicro (
CONVERT_TO=promicro_rp2040) - Firmware: vial-qmk (Vial-compatible QMK fork)
- Layout:
LAYOUT_split_3x6_3— 36 main keys + 3 thumb keys per half - Features:
- RGB Matrix with typing heatmap, alphas mods, band pinwheel/spiral, gradient effects
- RGB layer/color indicators per active layer
- Caps Lock indicator (rainbow or accent color)
- Idle dimming (fades after 60s, full off after 30min)
- Vial combos (10 entries), key overrides (10 entries), tap dance (10 entries)
- 10 dynamic macros
- Leader sequences, combos, key overrides, tap dance
- Unicode input (common + full)
- Auto-shift, retro shift, space cadet (sticky shift/ctrl on double-tap)
- NKRO
- Split sync: layer state, LED state, mods, transaction mirror
- USB auto-detect master/slave
Build:
nix build .#crkbd-choc-v2The UF2 firmware files are at result/share/qmk/firmware/{left,right}/.
Flash (RP2040 UF2 bootloader):
# Flash left half — double-tap reset when prompted:
nix run nixpkgs#qmk -- flash result/share/qmk/firmware/left/*.uf2 -bl uf2-split-left
# Flash right half — double-tap reset when prompted:
nix run nixpkgs#qmk -- flash result/share/qmk/firmware/right/*.uf2 -bl uf2-split-rightCorne Keyboard — same split 3x6 + 3 thumb layout, for Cherry MX compatible switches.
- MCU: AVR
- Firmware: vial-qmk (Vial-compatible QMK fork)
- Layout:
LAYOUT_split_3x6_3— 36 main keys + 3 thumb keys per half - Features:
- Vial combos (4 entries), tap dance (10 entries), key overrides (4 entries)
- 6 dynamic macros
- NKRO
- Split sync (layer/LED/mods)
- USB auto-detect master/slave
Build:
nix build .#crkbd-classic-v3The hex firmware files are at result/share/qmk/firmware/{left,right}/crkbd_rev1_classic-v3.hex.
Flash (Caterina bootloader, avrdude):
# Flash left half — double-tap reset when prompted:
nix run nixpkgs#qmk -- flash result/share/qmk/firmware/left/crkbd_rev1_classic-v3.hex -bl avrdude-split-left
# Flash right half — double-tap reset when prompted:
nix run nixpkgs#qmk -- flash result/share/qmk/firmware/right/crkbd_rev1_classic-v3.hex -bl avrdude-split-rightThese keymaps are designed for the EurKey layout — a multilingual layout based on QWERTY that provides Western European accented characters (French, Spanish, German, Portuguese, etc.) via Alt Gr combos, while keeping the familiar QWERTY base for coding and ASCII symbols.
TapDance keys produce different actions based on tap vs. hold timing. All slots use TD(...) in the keymap. These tap-dance keys replicate EurKey accented characters that are normally accessed via Alt Gr on the OS level.
| Slot | Tap | Hold/Double | Term | EurKey Char | Description |
|---|---|---|---|---|---|
| 0 | KC_A |
RALT(KC_X) |
200ms | á | Tap: A · Hold: AltGr+X → á |
| 1 | KC_E |
RALT(KC_G) |
200ms | é | Tap: E · Hold: AltGr+G → é |
| 2 | KC_I |
RALT(KC_B) |
200ms | í | Tap: I · Hold: AltGr+B → í |
| 3 | KC_O |
RALT(KC_DOT) |
200ms | ó | Tap: O · Hold: AltGr+. → ó |
| 4 | KC_U |
RALT(KC_J) |
200ms | ú | Tap: U · Hold: AltGr+J → ú |
| 5 | KC_N |
RALT(KC_N) |
200ms | ñ | Tap: N · Hold: AltGr+N → ñ |
| 6 | KC_C |
RALT(KC_C) |
200ms | ç | Tap: C · Hold: AltGr+C → ç |
| 7 | KC_LEFT_GUI |
KC_LEFT_ALT |
350ms | — | Tap: GUI (Win) · Hold: AltGr |
| 8 | KC_LEFT_SHIFT |
double tap → KC_CAPS_LOCK |
180ms | — | Tap: LShift · Double: CapsLock |
QWERTY Layer (0)
┌──┐ ┌──┐
┌──┐│E │┌──┐┌──┐ ┌──┐┌──┐│I │┌──┐
┌──┐┌──┐│W ││ ││R ││T │ │Y ││U ││ ││O │┌──┐┌──┐
│⎋ ││Q ││ │└──┘│ ││ │ │ ││ │└──┘│ ││P ││⌫ │
│ ││ │└──┘┌──┐└──┘└──┘ └──┘└──┘┌──┐└──┘│ ││ │
└──┘└──┘┌──┐│D │┌──┐┌──┐ ┌──┐┌──┐│K │┌──┐└──┘└──┘
┌──┐┌──┐│S ││ ││F ││G │ │H ││J ││ ││L │┌──┐┌──┐
│⇥ ││A ││ │└──┘│ ││ │ │ ││ │└──┘│ ││; ││⏎ │
│ ││ │└──┘┌──┐└──┘└──┘ └──┘└──┘┌──┐└──┘│ ││ │
└──┘└──┘┌──┐│TD│┌──┐┌──┐ ┌──┐┌──┐│, │┌──┐└──┘└──┘
┌──┐┌──┐│X ││6 ││V ││B │ │TD││M ││ ││. │┌──┐┌──┐
│TD││Z ││ │└──┘│ ││ │ │5 ││ │└──┘│ ││/ ││' │
│8 ││ │└──┘ └──┘└──┘ └──┘└──┘ └──┘│ ││ │
└──┘└──┘ ┌──┐ ┌──┐ ┌──┐ ┌──┐ ┌──┐ ┌──┐ └──┘└──┘
│L⌃│ │TD│ │␣ │ │␣ │ │MO│ │MO│
│ │ │7 │ │ │ │ │ │2 │ │1 │
└──┘ └──┘ │ │ │ │ └──┘ └──┘
│ │ │ │
└──┘ └──┘
Navigation Layer (1)
Layer 1 provides navigation keys (arrows, page up/down, home/end) and macros on the left, plus media/print keys on the right.
┌──┐ ┌──┐
┌──┐│3 │┌──┐┌──┐ ┌──┐┌──┐│*1│┌──┐
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│ ││ │└──┘┌──┐└──┘└──┘ └──┘└──┘┌──┐└──┘│ ││ │
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│ ││0 │└──┘┌──┐└──┘└──┘ └──┘└──┘┌──┐└──┘│ ││ │
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│▽ ││▽ ││ │└──┘│ ││ │ │ ││ │└──┘│ ││↓ ││→ │
│ ││ │└──┘ └──┘└──┘ └──┘└──┘ └──┘│ ││ │
└──┘└──┘ ┌──┐ ┌──┐ ┌──┐ ┌──┐ ┌──┐ ┌──┐ └──┘└──┘
│▽ │ │MO│ │▽ │ │▽ │ │MO│ │ │
│ │ │4 │ │ │ │ │ │5 │ │ │
└──┘ └──┘ │ │ │ │ └──┘ └──┘
│ │ │ │
└──┘ └──┘
*1 - KC_PRINT_SCREEN
| Symbol | Keycode | Description |
|---|---|---|
| MO | MO(4) / MO(5) |
Momentary layer switch to layer 4 or 5 |
Symbol Layer (2)
Layer 2 provides symbols via LSHIFT (left hand) and EurKey Alt Gr combos (right hand), with navigation on thumbs.
┌──┐ ┌──┐
┌──┐│L⇧│┌──┐┌──┐ ┌──┐┌──┐│L⇧│┌──┐
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│~ ││1 │└──┘┌──┐└──┘└──┘ └──┘└──┘┌──┐└──┘│0 ││ │
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└──┘└──┘ ┌──┐ ┌──┐ ┌──┐ ┌──┐ ┌──┐ ┌──┐ └──┘└──┘
│▽ │ │MO│ │▽ │ │▽ │ │ │ │MO│
│ │ │3 │ │ │ │ │ │ │ │5 │
└──┘ └──┘ │ │ │ │ └──┘ └──┘
│ │ │ │
└──┘ └──┘
*1 - RALT(KC_5)
*2 - L⇧,,
| Symbol | Keycode | Description |
|---|---|---|
| L⇧ | KC_LSFT |
Left Shift (for symbol access) |
| MO | MO(3) / MO(5) |
Momentary layer switch to layer 3 or 5 |
| *1 | RALT(KC_5) |
AltGr + 5 → € |
| *2 | KC_LSFT(KC_COMMA) |
Left Shift + comma → < |
F-keys / Number Layer (3)
Layer 3 provides F1-F12 on the left hand and a numpad-like layout on the right.
┌──┐ ┌──┐
┌──┐│F3│┌──┐┌──┐ ┌──┐┌──┐│8 │┌──┐
┌──┐┌──┐│F2││ ││F4││F5│ │K*││7 ││ ││9 │┌──┐┌──┐
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│ ││ │└──┘┌──┐└──┘└──┘ └──┘└──┘┌──┐└──┘│ ││ │
└──┘└──┘┌──┐│F8│┌──┐┌──┐ ┌──┐┌──┐│5 │┌──┐└──┘└──┘
┌──┐┌──┐│F7││ ││F9││F │ │K+││4 ││ ││6 │┌──┐┌──┐
│ ││F6││ │└──┘│ ││10│ │ ││ │└──┘│ ││K=││K⏎│
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│ ││11│└──┘ └──┘└──┘ └──┘└──┘ └──┘│ ││ │
└──┘└──┘ ┌──┐ ┌──┐ ┌──┐ ┌──┐ ┌──┐ ┌──┐ └──┘└──┘
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│ │ │ │ │ │ │ │ │ │ │ │
└──┘ └──┘ │ │ │ │ └──┘ └──┘
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└──┘ └──┘
Alt-F / Extended Symbols Layer (4)
Layer 4 maps to Alt+F (left hand) and Alt+Number (right hand) for media/number shortcuts.
┌──┐ ┌──┐
┌──┐│*1│┌──┐┌──┐ ┌──┐┌──┐│*2│┌──┐
┌──┐┌──┐│*3││ ││*4││*7│ │*8││*5││ ││*6│┌──┐┌──┐
│▽ ││*9││ │└──┘│ ││ │ │ ││ │└──┘│ ││*10│▽ │
│ ││ │└──┘┌──┐└──┘└──┘ └──┘└──┘┌──┐└──┘│ ││ │
└──┘└──┘┌──┐│*11┌──┐┌──┐ ┌──┐┌──┐│*12┌──┐└──┘└──┘
┌──┐┌──┐│*13│ ││*14│*17 │*18│*15│ ││*16┌──┐┌──┐
│▽ ││*19│ │└──┘│ ││ │ │ ││ │└──┘│ ││*20│▽ │
│ ││ │└──┘┌──┐└──┘└──┘ └──┘└──┘┌──┐└──┘│ ││ │
└──┘└──┘┌──┐│ │┌──┐┌──┐ ┌──┐┌──┐│ │┌──┐└──┘└──┘
┌──┐┌──┐│*21│ ││ ││ │ │ ││ ││ ││ │┌──┐┌──┐
│▽ ││*22│ │└──┘│ ││ │ │ ││ │└──┘│ ││ ││ │
│ ││ │└──┘ └──┘└──┘ └──┘└──┘ └──┘│ ││ │
└──┘└──┘ ┌──┐ ┌──┐ ┌──┐ ┌──┐ ┌──┐ ┌──┐ └──┘└──┘
│▽ │ │▽ │ │▽ │ │▽ │ │ │ │ │
│ │ │ │ │ │ │ │ │ │ │ │
└──┘ └──┘ │ │ │ │ └──┘ └──┘
│ │ │ │
└──┘ └──┘
| Ref | Keycode | Description |
|---|---|---|
| *1 | LALT(KC_F3) |
AltGr + F3 |
| *2 | RALT(KC_3) |
AltGr + 3 |
| *3 | LALT(KC_F2) |
AltGr + F2 |
| *4 | LALT(KC_F4) |
AltGr + F4 |
| *5 | RALT(KC_2) |
AltGr + 2 |
| *6 | RALT(KC_4) |
AltGr + 4 |
| *7 | LALT(KC_F5) |
AltGr + F5 |
| *8 | RALT(KC_1) |
AltGr + 1 |
| *9 | LALT(KC_F1) |
AltGr + F1 |
| *10 | RALT(KC_5) |
AltGr + 5 |
| *11 | LALT(KC_F8) |
AltGr + F8 |
| *12 | RALT(KC_8) |
AltGr + 8 |
| *13 | LALT(KC_F7) |
AltGr + F7 |
| *14 | LALT(KC_F9) |
AltGr + F9 |
| *15 | RALT(KC_7) |
AltGr + 7 |
| *16 | RALT(KC_9) |
AltGr + 9 |
| *17 | LALT(KC_F10) |
AltGr + F10 |
| *18 | RALT(KC_6) |
AltGr + 6 |
| *19 | LALT(KC_F6) |
AltGr + F6 |
| *20 | RALT(KC_0) |
AltGr + 0 |
| *21 | LALT(KC_F12) |
AltGr + F12 |
| *22 | LALT(KC_F11) |
AltGr + F11 |
Media / System (5)
Layer 5 provides media controls (volume, playback) on the left hand and system/magic keys on the right.
┌──┐ ┌──┐
┌──┐│ │┌──┐┌──┐ ┌──┐┌──┐│ │┌──┐
┌──┐┌──┐│V+││ ││ ││ │ │*2││*1││ ││ │┌──┐┌──┐
│ ││ ││ │└──┘│ ││ │ │ ││ │└──┘│ ││ ││*3│
│ ││ │└──┘┌──┐└──┘└──┘ └──┘└──┘┌──┐└──┘│ ││ │
└──┘└──┘┌──┐│>>│┌──┐┌──┐ ┌──┐┌──┐│ │┌──┐└──┘└──┘
┌──┐┌──┐│V-││ ││ ││ │ │ ││ ││ ││ │┌──┐┌──┐
│ ││<<││ │└──┘│ ││ │ │ ││ │└──┘│ ││ ││ │
│ ││ │└──┘┌──┐└──┘└──┘ └──┘└──┘┌──┐└──┘│ ││ │
└──┘└──┘┌──┐│ │┌──┐┌──┐ ┌──┐┌──┐│ │┌──┐└──┘└──┘
┌──┐┌──┐│ ││ ││ ││ │ │ ││ ││ ││ │┌──┐┌──┐
│ ││ ││ │└──┘│ ││ │ │ ││ │└──┘│ ││ ││ │
│ ││ │└──┘ └──┘└──┘ └──┘└──┘ └──┘│ ││ │
└──┘└──┘ ┌──┐ ┌──┐ ┌──┐ ┌──┐ ┌──┐ ┌──┐ └──┘└──┘
│ │ │ │ │⏯ │ │Mut │ │ │ │
│ │ │ │ │ │ │ │ │ │ │ │
└──┘ └──┘ │ │ │ │ └──┘ └──┘
│ │ │ │
└──┘ └──┘
*1 - QK_MAGIC_EE_HANDS_RIGHT
*2 - QK_MAGIC_EE_HANDS_LEFT
*3 - QK_BOOTLOADER
| Symbol | Keycode | Description |
|---|---|---|
| V+ | KC_VOLUME_UP |
Volume up |
| V- | KC_VOLUME_DOWN |
Volume down |
| << | KC_PREVIOUS |
Previous track |
| >> | KC_NEXT |
Next track |
| ⏯ | KC_PLAY_PAUSE |
Play/pause toggle |
| Mut | KC_MUTE |
Mute audio |
| *1 | QK_MAGIC_EE_HANDS_RIGHT |
Magic: sync EEPROM to right hand |
| *2 | QK_MAGIC_EE_HANDS_LEFT |
Magic: sync EEPROM to left hand |
| *3 | QK_BOOTLOADER |
Reboot into bootloader (for flashing) |
# Corne Chocolate v2 (RP2040, UF2)
nix build .#crkbd-choc-v2
# Corne Classic v3 (AVR, hex)
nix build .#crkbd-classic-v3The compiled firmware is in result/share/qmk/firmware/{left,right}/.
The -bl avrdude-split-left / -bl uf2-split-left bootloaders wait interactively for you to double-tap reset, then flash and set EEPROM handedness.
Corne Classic v3 (AVR):
nix run nixpkgs#qmk -- flash result/share/qmk/firmware/left/crkbd_rev1_classic-v3.hex -bl avrdude-split-left
nix run nixpkgs#qmk -- flash result/share/qmk/firmware/right/crkbd_rev1_classic-v3.hex -bl avrdude-split-rightCorne Chocolate v2 (RP2040):
nix run nixpkgs#qmk -- flash result/share/qmk/firmware/left/*.uf2 -bl uf2-split-left
nix run nixpkgs#qmk -- flash result/share/qmk/firmware/right/*.uf2 -bl uf2-split-rightRender the keyboard layout from a connected keyboard:
nix run path:.#vitaly -- layers -n <layer-number>fetchQmkFirmwarefetches vial-qmk at a pinned commit and primes the repobuildQmkFirmwareinjects local keymap source (src) into the firmware tree at the mount path (srcMount), then runs the QMK build- Each keymap is a separate package, built independently
See the QMix docs for full details on fetchQmkFirmware and buildQmkFirmware.
To update the vial-qmk source, change rev and hash in flake.nix:
vialQmkFirmware = pkgs.fetchQmkFirmware {
url = "https://github.com/vial-kb/vial-qmk.git";
origin = "https://github.com/vial-kb/vial-qmk.git";
rev = "..."; # new commit hash
hash = "sha256-..."; # compute with `nix-prefetch-git` or let nix suggest it
};- Create a directory under
keyboards/crkbd/keymaps/<name>/ - Add
keymap.c,config.h,rules.mk, andvial.json - Add a package entry in
flake.nix:
my-keymap = pkgs.buildQmkFirmware {
keyboard = "crkbd";
keymap = "my-keymap";
split = true;
src = ./keyboards/crkbd/keymaps/my-keymap;
srcMount = "keyboards/crkbd/keymaps/my-keymap";
qmkFirmware = vialQmkFirmware;
};