qmk_firmware/tmk_core/common/bootmagic_lite.c

#include "quantum.h"

/** \brief Reset eeprom
 *
 * ...just incase someone wants to only change the eeprom behaviour
 */
__attribute__((weak)) void bootmagic_lite_reset_eeprom(void) {
#if defined(VIA_ENABLE)
    via_eeprom_reset();
#else
    eeconfig_disable();
#endif
}

/** \brief The lite version of TMK's bootmagic based on Wilba.
 *
 *  100% less potential for accidentally making the keyboard do stupid things.
 */
__attribute__((weak)) void bootmagic_lite(void) {
    // We need multiple scans because debouncing can't be turned off.
    matrix_scan();
#if defined(DEBOUNCE) && DEBOUNCE > 0
    wait_ms(DEBOUNCE * 2);
#else
    wait_ms(30);
#endif
    matrix_scan();

    // If the configured key (commonly Esc) is held down on power up,
    // reset the EEPROM valid state and jump to bootloader.
    // This isn't very generalized, but we need something that doesn't
    // rely on user's keymaps in firmware or EEPROM.
    uint8_t row = BOOTMAGIC_LITE_ROW;
    uint8_t col = BOOTMAGIC_LITE_COLUMN;

#if defined(SPLIT_KEYBOARD) && defined(BOOTMAGIC_LITE_ROW_RIGHT) && defined(BOOTMAGIC_LITE_COLUMN_RIGHT)
    if (!is_keyboard_left()) {
        row = BOOTMAGIC_LITE_ROW_RIGHT;
        col = BOOTMAGIC_LITE_COLUMN_RIGHT;
    }
#endif

    if (matrix_get_row(row) & (1 << col)) {
        bootmagic_lite_reset_eeprom();

        // Jump to bootloader.
        bootloader_jump();
    }
}