hwdef-info

name	hwdef-info
description	Show hardware definition details for an ArduPilot board. Use when the user asks about board pinouts, peripherals, MCU type, UART mappings, or hwdef.dat contents.

ArduPilot Hardware Definition Info

Show hardware definition details for board $ARGUMENTS.

Workflow

Step 1: Find the board's hwdef directory

ls libraries/AP_HAL_ChibiOS/hwdef/ | grep -i "$ARGUMENTS"

Board directories are at libraries/AP_HAL_ChibiOS/hwdef/<board_name>/.

Step 2: Read the hwdef.dat

Read the main hardware definition file:

Read: libraries/AP_HAL_ChibiOS/hwdef/<board_name>/hwdef.dat

Step 3: Extract key information

Report:

• MCU: type and variant (e.g., STM32H743)
• Flash: size in KB
• Board ID: APJ_BOARD_ID value
• UARTs: SERIAL_ORDER mapping (which SERIALn = which UART)
• I2C: bus ordering
• SPI: devices and bus assignments
• ADC pins: battery voltage/current sensing
• PWM outputs: timer channels and GPIO mappings
• CAN: interfaces available
• LEDs: onboard LED pins
• IMU/Baro/Mag: onboard sensor defines
• Included files: any include directives (for boards that inherit from others)
• Default parameters: read defaults.parm if it exists

Step 4: Check for variants

Look for related boards:

• <board_name>-periph (AP_Periph variant)
• Bootloader definition (hwdef-bl.dat)

hwdef.dat key directives

Directive	Purpose
MCU	MCU family and specific type
FLASH_SIZE_KB	Flash memory
APJ_BOARD_ID	Unique board ID for firmware loading
SERIAL_ORDER	Maps SERIALn to physical UART
I2C_ORDER	Maps I2C bus numbers
Pxx FUNC PERIPH	Pin assignment (e.g., PA0 UART4_TX UART4)
define	Compile-time defines
include	Inherit from another hwdef
env	Set build environment (e.g., env AP_PERIPH 1)
IOMCU_UART	IOMCU connection UART
STORAGE_FLASH_PAGE	Flash page for parameter storage

Special board types

• Periph boards (-periph suffix): Include parent hwdef + set env AP_PERIPH 1
• Linux boards: Defined in libraries/AP_HAL_Linux/hwdef/
• ESP32 boards: Defined in libraries/AP_HAL_ESP32/hwdef/
• SITL: No hwdef.dat — virtual board