Flash the Bootloader for the First Time

February 14, 2026 ยท View on GitHub

This tutorial gets a fresh RP2040 board running the Crispy bootloader.

Prerequisites

  • RP2040 board (for example Raspberry Pi Pico)
  • USB cable
  • Rust toolchain
  • cargo-binutils + llvm-tools-preview

Install tools:

make install-tools

1. Build bootloader UF2

make bootloader-uf2

Expected artifact:

  • target/thumbv6m-none-eabi/release/crispy-bootloader.uf2

2. Flash via BOOTSEL mode

  1. Hold BOOTSEL while plugging or resetting the board.
  2. Mount the RPI-RP2 drive.
  3. Copy the UF2 file:
cp target/thumbv6m-none-eabi/release/crispy-bootloader.uf2 /media/$USER/RPI-RP2/

3. Verify bootloader is alive

cargo run --release -p crispy-upload-rs -- --port /dev/ttyACM0 status

You should see bootloader version, active bank, and firmware bank version fields.

Next steps