Compile PicoBoot firmware

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The recommended way to build PicoBoot is using VS Code with the provided devcontainer environment. This ensures all dependencies are properly set up and consistent across different development machines.

Development Environment Setup

1. Install VS Code
2. Install Docker
3. Install Remote - Containers extension in VS Code
4. Clone the PicoBoot repository
5. Open the project in VS Code
6. When prompted, click "Reopen in Container" or use Command Palette (F1) and select "Remote-Containers: Reopen in Container"

The devcontainer includes all necessary dependencies including the Raspberry Pi Pico SDK.

Building PicoBoot

Starting with v0.4 release, PicoBoot introduced split payload from modchip code. Now only part of the Pico can be updated to replace starting homebrew application. This was done in order to make PicoBoot more resilient to corrupted flash memory as well as to enforce interoperability between PicoBoot and other projects like gekkoboot or Swiss.

To build PicoBoot:

1. Place your payload.dol file in the project root directory

   • The entrypoint address of the *.dol must be 0x81300000
   • gekkoboot is recommended and this is what PicoBoot releases are shipped with

2. Run the build script:

./tools/build.sh

After successful build, you'll find the following files in the dist/ directory:

• payload_*.uf2 - payload file for partial update
• picoboot_*.uf2 - modchip code for partial udpate
• picoboot_full_*.uf2 - full firmware + payload file, recommended for end-users and testing

Flashing the Firmware

To flash new firmware to your Pico board:

1. Boot the Pico in BOOTSEL mode (hold BOOTSEL button and plug USB cable)
2. Copy picoboot_full_*.uf2 file to the new RPI-RP2 (or RP2350) device
3. The device will auto-eject and the green LED will light up on Pico