qmk-firmware/docs/feature_bootmagic.md

Bootmagic

There are three separate but related features that allow you to change the behavior of your keyboard without reflashing. While each of them have similar functionality, it is accessed in different ways depending on how your keyboard is configured.

Bootmagic is a system for configuring your keyboard while it initializes. To trigger a Bootmagic command, hold down the Bootmagic key and one or more command keys.

Bootmagic Keycodes are prefixed with MAGIC_, and allow you to access the Bootmagic functionality after your keyboard has initialized. To use the keycodes, assign them to your keymap as you would any other keycode.

Command, formerly known as Magic, is another feature that allows you to control different aspects of your keyboard. While it shares some functionality with Bootmagic, it also allows you to do things that Bootmagic does not, such as printing version information to the console. For more information, see Command.

On some keyboards Bootmagic is disabled by default. If this is the case, it must be explicitly enabled in your rules.mk with:

BOOTMAGIC_ENABLE = full

?> You may see yes being used in place of full, and this is okay. However, yes is deprecated, and ideally full (or lite) should be used instead.

Additionally, you can use Bootmagic Lite (a scaled down, very basic version of Bootmagic) by adding the following to your rules.mk file:

BOOTMAGIC_ENABLE = lite

Hotkeys

Hold down the Bootmagic key (Space by default) and the desired hotkey while plugging in your keyboard. For example, holding Space+B should cause it to enter the bootloader.

Hotkey	Description
Escape	Ignore Bootmagic configuration in EEPROM
B	Enter the bootloader
D	Toggle debugging over serial
X	Toggle key matrix debugging
K	Toggle keyboard debugging
M	Toggle mouse debugging
Backspace	Clear the EEPROM
Caps Lock	Toggle treating Caps Lock as Left Control
Left Control	Toggle swapping Caps Lock and Left Control
Left Alt	Toggle swapping Left Alt and Left GUI
Right Alt	Toggle swapping Right Alt and Right GUI
Left GUI	Toggle the GUI keys (useful when gaming)
`	Toggle swapping ` and Escape
\	Toggle swapping \ and Backspace
N	Toggle N-Key Rollover (NKRO)
0	Make layer 0 the default layer
1	Make layer 1 the default layer
2	Make layer 2 the default layer
3	Make layer 3 the default layer
4	Make layer 4 the default layer
5	Make layer 5 the default layer
6	Make layer 6 the default layer
7	Make layer 7 the default layer

Keycodes

Keycode	Aliases	Description
MAGIC_CAPSLOCK_TO_CONTROL		Treat Caps Lock as Left Control
MAGIC_UNCAPSLOCK_TO_CONTROL		Stop treating Caps Lock as Left Control
MAGIC_HOST_NKRO		Force N-Key Rollover (NKRO) on
MAGIC_UNHOST_NKRO		Force NKRO off
MAGIC_TOGGLE_NKRO		Turn NKRO on or off
MAGIC_NO_GUI		Disable the GUI keys (useful when gaming)
MAGIC_UNNO_GUI		Enable the GUI keys
MAGIC_SWAP_ALT_GUI	AG_SWAP	Swap Alt and GUI on both sides (for macOS)
MAGIC_UNSWAP_ALT_GUI	AG_NORM	Unswap Left Alt and Left GUI
MAGIC_TOGGLE_ALT_GUI	AG_TOGG	Toggle Left Alt and GUI swap
MAGIC_SWAP_BACKSLASH_BACKSPACE		Swap \ and Backspace
MAGIC_UNSWAP_BACKSLASH_BACKSPACE		Unswap \ and Backspace
MAGIC_SWAP_CONTROL_CAPSLOCK		Swap Left Control and Caps Lock
MAGIC_UNSWAP_CONTROL_CAPSLOCK		Unswap Left Control and Caps Lock
MAGIC_SWAP_GRAVE_ESC		Swap ` and Escape
MAGIC_UNSWAP_GRAVE_ESC		Unswap ` and Escape
MAGIC_SWAP_LALT_LGUI		Swap Left Alt and Left GUI
MAGIC_UNSWAP_LALT_LGUI		Unswap Left Alt and Left GUI
MAGIC_SWAP_RALT_RGUI		Swap Right Alt and Right GUI
MAGIC_UNSWAP_RALT_RGUI		Unswap Right Alt and Right GUI

Configuration

If you would like to change the hotkey assignments for Bootmagic, #define these in your config.h at either the keyboard or keymap level.

Define	Default	Description
BOOTMAGIC_KEY_SALT	KC_SPACE	The Bootmagic key
BOOTMAGIC_KEY_SKIP	KC_ESC	Ignore Bootmagic configuration in EEPROM
BOOTMAGIC_KEY_EEPROM_CLEAR	KC_BSPACE	Clear the EEPROM configuration
BOOTMAGIC_KEY_BOOTLOADER	KC_B	Enter the bootloader
BOOTMAGIC_KEY_DEBUG_ENABLE	KC_D	Toggle debugging over serial
BOOTMAGIC_KEY_DEBUG_MATRIX	KC_X	Toggle matrix debugging
BOOTMAGIC_KEY_DEBUG_KEYBOARD	KC_K	Toggle keyboard debugging
BOOTMAGIC_KEY_DEBUG_MOUSE	KC_M	Toggle mouse debugging
BOOTMAGIC_KEY_SWAP_CONTROL_CAPSLOCK	KC_LCTRL	Swap Left Control and Caps Lock
BOOTMAGIC_KEY_CAPSLOCK_TO_CONTROL	KC_CAPSLOCK	Toggle treating Caps Lock as Left Control
BOOTMAGIC_KEY_SWAP_LALT_LGUI	KC_LALT	Toggle swapping Left Alt and Left GUI (for macOS)
BOOTMAGIC_KEY_SWAP_RALT_RGUI	KC_RALT	Toggle swapping Right Alt and Right GUI (for macOS)
BOOTMAGIC_KEY_NO_GUI	KC_LGUI	Toggle the GUI keys (useful when gaming)
BOOTMAGIC_KEY_SWAP_GRAVE_ESC	KC_GRAVE	Toggle swapping ` and Escape
BOOTMAGIC_KEY_SWAP_BACKSLASH_BACKSPACE	KC_BSLASH	Toggle swapping \ and Backspace
BOOTMAGIC_HOST_NKRO	KC_N	Toggle N-Key Rollover (NKRO)
BOOTMAGIC_KEY_DEFAULT_LAYER_0	KC_0	Make layer 0 the default layer
BOOTMAGIC_KEY_DEFAULT_LAYER_1	KC_1	Make layer 1 the default layer
BOOTMAGIC_KEY_DEFAULT_LAYER_2	KC_2	Make layer 2 the default layer
BOOTMAGIC_KEY_DEFAULT_LAYER_3	KC_3	Make layer 3 the default layer
BOOTMAGIC_KEY_DEFAULT_LAYER_4	KC_4	Make layer 4 the default layer
BOOTMAGIC_KEY_DEFAULT_LAYER_5	KC_5	Make layer 5 the default layer
BOOTMAGIC_KEY_DEFAULT_LAYER_6	KC_6	Make layer 6 the default layer
BOOTMAGIC_KEY_DEFAULT_LAYER_7	KC_7	Make layer 7 the default layer

Bootmagic Lite

In addition to the full blown Bootmagic feature, is the Bootmagic Lite feature that only handles jumping into the bootloader. This is great for boards that don't have a physical reset button but you need a way to jump into the bootloader, and don't want to deal with the headache that Bootmagic can cause.

To enable this version of Bootmagic, you need to enable it in your rules.mk with:

BOOTMAGIC_ENABLE = lite

Additionally, you may want to specify which key to use. This is especially useful for keyboards that have unusual matrices. To do so, you need to specify the row and column of the key that you want to use. Add these entries to your config.h file:

#define BOOTMAGIC_LITE_ROW 0
#define BOOTMAGIC_LITE_COLUMN 1

By default, these are set to 0 and 0, which is usually the "ESC" key on a majority of keyboards.

And to trigger the bootloader, you hold this key down when plugging the keyboard in. Just the single key.

Advanced Bootmagic Lite

The bootmagic_lite function is defined weakly, so that you can replace this in your code, if you need. A great example of this is the Zeal60 boards that have some additional handling needed.

To replace the function, all you need to do is add something like this to your code:

void bootmagic_lite(void) {
    matrix_scan();
    wait_ms(DEBOUNCING_DELAY * 2);
    matrix_scan();

    if (matrix_get_row(BOOTMAGIC_LITE_ROW) & (1 << BOOTMAGIC_LITE_COLUMN)) {
      // Jump to bootloader.
      bootloader_jump();
    }
}

You can additional feature here. For instance, resetting the eeprom or requiring additional keys to be pressed to trigger bootmagic. Keep in mind that bootmagic_lite is called before a majority of features are initialized in the firmware.