I have a dumb question. Can someone provide/link to an explanation of what SPI is? Knowing that it is “Serial Peripheral Interface” doesn’t really help.
It is a chip on the board, right? What in general are its tasks? How is it used for booting? And what are the other ways of booting? Should I use it or avoid it?
Hi @incognito
While SPI in general is just the name of a type of communication bus, with this device we are usually referring to a SPI flash chip. In this case this chip is just a 16MB large memory chip. By default it currently is empty but it can be programmed with an image of U-Boot that can act as a bootloader and extend the native capabilities of the RK3588 SoC. By itself the RK3588 can boot from SD card, eMMC and this SPI flash chip. When a bootable image is available on the SPI flash it will be started and the image then can load some more drivers that allows booting from other devices/interfaces (e.g. NVMe, USB, Ethernet, etc.) or provide other functionality. 16MB is not much but sufficient for a basic bootloader.
There are already 3 bootable of the i believe 5 available.
MicroSdCard
NVME
eMMC
USB (probably will come)
In the topic i made i aksed the question about being able to also boot from USB. Answer is there. So what is left is network boot (not sure if this is possible).