Installation instructions
Installing to SPI (recommended)
NOTE: The SoC startup order for Rockchip systems will prefer SPI, then eMMC, followed by SD last.
You may need to prevent default startup sources from being used to install using the Tow-Boot installer image.
By installing Tow-Boot to SPI, your Radxa ROCK Pi 4 model A/B will be able to start using standards-based booting without conflicting with the operating system storage.
To do so, you will need to write the SPI installer image to an SD card.
# dd if=spi.installer.img of=/dev/XXX bs=1M oflag=direct,sync status=progress
Once done, start the system, and in the boot menu, select “Flash firmware to SPI”.
Once this is done, remove the installation media, and verify Tow-Boot starts from power-on.
Installing to shared storage
Using the shared storage strategy on the Radxa ROCK Pi 4 model A/B can be done by
writing the shared.disk-image.img to an SD card or eMMC.
# dd if=shared.disk-image.img of=/dev/XXX bs=1M oflag=direct,sync status=progress
Device-specific notes
According to the upstream SPI documentation, the SPI flash is only populated on board revisions V1.4 and later.
While the schematics denote W25Q64FV is used, all verified units came
with an XT25F32B.
If no flash is present, the user either needs to use the shared storage strategy,
or needs to manually solder on some pin-compatible SPI flash (SOP8 footprint).