| 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. |
| argument-hint | <board_name> |
| allowed-tools | Glob, Grep, Read, Bash(ls *) |
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
