USB boot code
This is the USB MSD boot code which should work on the Raspberry Pi model A, Compute Module, Compute Module 3, Compute Module 4 and Raspberry Pi Zero.
This version of rpiboot has been modified to work from directories which contain the booting firmware. There is a msd/ directory which contains bootcode.bin and start.elf to turn the Raspberry Pi device into a USB Mass Storage Device (MSD). If run without arguments embedded versions of bootcode.bin and start.elf are used to enable the MSD behaviour.
For more information run 'rpiboot -h'
Building
Clone this on your Pi or an Ubuntu linux machine
git clone --depth=1 https://github.com/raspberrypi/usbboot
cd usbboot
sudo apt install libusb-1.0-0-dev
make
sudo ./rpiboot
Running your own (not MSD) build
If you would like to boot the Raspberry Pi with a standard build you just need to copy the FAT partition files into a subdirectory (it must have at the minimum bootcode.bin and start.elf). If you take a standard firmware release then this will at the very least boot the linux kernel which will then stop (and possibly crash!) when it looks for a filesystem. To provide a filesystem there are many options, you can build an initramfs into the kernel, add an initramfs to the boot directory or provide some other interface to the filesystem.
sudo ./rpiboot -d boot
This will serve the boot directory to the Raspberry Pi Device.
Compute Module 4
On Compute Module 4 EMMC-DISABLE / nRPIBOOT (GPIO 40) must be fitted to switch the ROM to usbboot mode. Otherwise, the SPI EEPROM bootloader image will be loaded instead.
Raspberry Pi Imager - BETA
The Raspberry Pi Imager can be run natively on the CM4 providing a GUI for downloading and installing the operating system.
Beta notes:
- The current version runs rpi-update upon completion in order to update the firwamre and kernel to support NVMe.
- uart_2ndstage is enabled
- The HDMI display is limited to 1080p to avoid potential problems with cables etc if a 4K display is attached.
For NVMe boot update the bootloader first:
sudo ./rpiboot -d nvme
Run Raspberry Pi Imager:
sudo ./rpiboot -d imager
Once the imager is running you will be prompted to remove the micro-usb cable and connect a mouse.