qmk_firmware/keyboards/matrix/abelx/rules.mk

## chip/board settings
# - the next two should match the directories in
#   <chibios>/os/hal/ports/$(MCU_FAMILY)/$(MCU_SERIES)
MCU_FAMILY = STM32
MCU_SERIES = STM32F4xx

# Linker script to use
# - it should exist either in <chibios>/os/common/ports/ARMCMx/compilers/GCC/ld/
#   or <this_dir>/ld/
MCU_LDSCRIPT = abelx_boot

# Startup code to use
#  - it should exist in <chibios>/os/common/startup/ARMCMx/compilers/GCC/mk/
MCU_STARTUP = stm32f4xx

# Board: it should exist either in <chibios>/os/hal/boards/
#  or <this_dir>/boards
BOARD = abelx_bd

# Cortex version
MCU  = cortex-m4

# ARM version, CORTEX-M0/M1 are 6, CORTEX-M3/M4/M7 are 7
ARMV = 7

USE_FPU = yes

# Bootloader selection
BOOTLOADER = custom

# Build Options
#   change yes to no to disable
#
BOOTMAGIC_ENABLE = yes      # Enable Bootmagic Lite
MOUSEKEY_ENABLE = yes       # Mouse keys
EXTRAKEY_ENABLE = yes       # Audio control and System control
CONSOLE_ENABLE = no         # Console for debug
COMMAND_ENABLE = no         # Commands for debug and configuration
NKRO_ENABLE = no            # Enable N-Key Rollover
BACKLIGHT_ENABLE = no       # Enable keyboard backlight functionality
RGBLIGHT_ENABLE = yes       # Enable keyboard RGB underglow
AUDIO_ENABLE = no           # Audio output
NO_USB_STARTUP_CHECK = yes  # Disable initialization only when usb is plugged in

CUSTOM_MATRIX = lite
# project specific files
SRC += matrix.c tca6424.c aw9523b.c
I2C_DRIVER_REQUIRED = yes