Stellaris UART

Bare-metal firmware project for the QEMU lm3s6965evb virtual board.

The target is a Cortex-M3-based Stellaris LM3S6965 environment. The project uses a custom linker script, a Cortex-M3 startup file, and the arm-none-eabi GCC toolchain.

Requirements

• CMake 3.20 or newer
• arm-none-eabi-gcc
• arm-none-eabi-objcopy
• arm-none-eabi-size
• QEMU with ARM system emulation
• clangd (optional, for editor integration)

Configure and build

cmake -S . -B build \
  -DCMAKE_TOOLCHAIN_FILE=cmake/arm-none-eabi.cmake
cmake --build build

Build artifacts are generated inside build/:

• stellaris_uart.elf: ELF image for debugging.
• stellaris_uart.bin: raw binary firmware image.
• stellaris_uart.map: linker map file.
• compile_commands.json: compilation database for tools such as clangd.

Run in QEMU

cmake --build build --target qemu

The QEMU target runs the firmware using the lm3s6965evb machine and connects UART output to the terminal. To exit QEMU, press Ctrl-A followed by x.

clangd integration

The .clangd file points clangd to the compilation database in build/. After configuring the project, clangd uses the same compiler flags as the firmware build, including:

• -mcpu=cortex-m3
• -mthumb
• -ffreestanding