Bare metal STM32 development in Odin. Includes svd2odin, a code generator that converts SVD files into type-safe Odin register definitions.

Status: Work in progress. Core functionality works, some drivers incomplete, not everything is tested. Not much is documented. probably bugs in some places. i have not yet written 'real' projects yet, mostly just building infrastructure, so I am not yet certain the design of the modules is ideal or not.

I have each of the following boards and intend to build at least some examples for each. ESP32 support is not planned. You need to use the Xtensa Fork of LLVM, and I dont feel like chasing that down. If someone else wants to add it, ill take the PR so long as its well documented how it works.

STM32F303 Discovery - Done WeAct F411 Black Pill - Partial / In Work (uses v3 minie as debug interface) STM32F103 Nucleo - Not Started STM32F103 Blue Pill - Not Started Pico2 RP2350 - Not Started Pico2W RP2350 - Not Started WRL-25134 SparkFun Thing Plus RP2350 - Not Started STM32 L432KC Nucleo - Not Started Adafruit Feather nRF52840 Express - Not Started

Either use of a Nucleo board which has its own internal debug interface / TX-ONLY virtual serial port, or a ST-Link V3-Minie (Strongly recomend this one). The cheap chinese clone V2 ST-Links were highly unreliable for me. The V3SET seemed like a mess, i never got it talking to the F411. I have not tried the V3SET on official STM Boards yet.

V3-Minie Solder Pads: CLK: SWSCK TMS: SWDIO GND: Ground VCC: 3v3 (This is a voltage sense-line)

I used Male-Female jumpers, soldering the male side directly to the v3 pads. I found someone who did a male 2x5 header pad and got it soldered to the v3-minie and it looks much nicer. this would allow female-female jumpers to the target board.

Arch Linux:

sudo pacman -S arm-none-eabi-gcc arm-none-eabi-newlib arm-none-eabi-gdb openocd stlink

Ubuntu/Debian:

sudo apt install gcc-arm-none-eabi libnewlib-arm-none-eabi gdb-multiarch openocd stlink-tools

macOS (Homebrew):

(I think? untested)

brew install arm-none-eabi-gcc openocd stlink

git clone <repo-url>
cd stm32

SVD files contain register definitions for your chip. Download from:

• TinyGo mirror: https://github.com/tinygo-org/stm32-svd
• ST product page → "CAD Resources" → "System View Description"

Place SVD files in the svd/ directory.

Copy an existing board config as a starting point:

cp boards/blackpill_f411/board.yaml my_board.yaml

Edit to match your board's MCU, memory layout, clocks, and GPIO. See the F303/F411 Blackpill examples, or read the yaml config parser (ill work on documenting better as this matures).

# Build the code generator
cd svd2odin && ./build.sh && cd ..

# Generate peripheral code and drivers
./svd2odin/svd2odin my_board.yaml src/stm32

This generates:

• src/stm32/cmsis/device/*.odin - Register definitions for all peripherals
• src/stm32/board/ - Startup code, linker script, GPIO config
• src/stm32/drivers/ - UART, SPI, I2C, DMA drivers
• src/stm32/hal/ - Portable register operations

(See Examples)

./build.sh

Output: build/firmware.bin

st-flash write build/firmware.bin 0x08000000

Or use ./flash.sh which builds and flashes in one step.

stm32/
├── src/
│   ├── main.odin              # Your application
│   └── stm32/                 # Generated code
│       ├── board/             # Board-specific (startup, linker script)
│       ├── cmsis/device/      # Peripheral registers
│       ├── drivers/           # High-level drivers (uart, spi, i2c, ...)
│       ├── hal/               # Portable register operations
│       └── freestanding/      # Runtime (allocator, panic handlers)
├── svd/                       # SVD files
├── boards/                    # Board configuration files
├── svd2odin/                  # Code generator
│   ├── src/                   # Generator source
│   ├── driver_templates/      # Driver templates
│   └── examples/              # Example projects
├── build.sh                   # Build firmware
├── flash.sh                   # Build and flash
├── regenerate.sh              # Regenerate all code from SVD
└── board.yaml                 # Active board config (symlink)

If you modify board.yaml or want to regenerate everything:

./regenerate.sh

For UART debug output:

# Check for USB serial device
ls /dev/ttyUSB* /dev/ttyACM*

# Connect with minicom
minicom -D /dev/ttyACM0 -b 115200

# Or raw terminal
stty -F /dev/ttyACM0 115200 raw -echo
cat /dev/ttyACM0

See svd2odin/examples/f303_discovery/ for working examples:

• LED animation
• RTC (Real-Time Clock)
• Watchdog timer
• I2C accelerometer/magnetometer
• SPI gyroscope
• UART with interrupts

• Some F4 series drivers need register type fixes for SPI/I2C
• F411 Blackpill: examples incomplete, havent figured out flashing DFU yet.
• RTTI is enabled due to runtime.Allocator issues (~20-40KB overhead)

BSD-3