As time goes on the answer may change …
There are lots of conflicting google reports
if so how
I understand booting from spi.
I am not able to make a bootable SD card with dd, even with conv=fsync
I can make a bootable SD card with etcher
I put the latest debian image on nvme with dd. It does NOT boot, but with SD card plugged in it becomes root fs and all is normal.
So can nvme boot? will writing the image with etcher help boot?
dd use .img files, not img.gz . Unpack .gz before
With spi is possible booting only some types of nvme. You have not bootable type. Use boot with SD.
Of course I use .img not .img.gz
I’m using the official lenovo M2
Do your words imply you can boot SPI or SD but not NVME
Yes.
Rockchip RK3399 can boot from SPI flash, eMMC storage, and SD card.
http://opensource.rock-chips.com/wiki_Boot_option
To run from NVMe or USB, one needs to boot via SPI flash or eMMC/SD.
As @rua1 mentioned, some NVMe drives are supported for booting via SPI. some not.
Mentioned in the wiki: https://wiki.radxa.com/Rockpi4/FAQs#Hardware
I put it there
OK here is my summary. Corrections welcome
boot is the process of reading initial data from the HD
rootfs is where your system is running
rockpi can boot from SPI-flash SD-card eMMC
rootfs requires a supported nvme if on nvme when booting from SPI
Any nvme if booting from SD - dunno, the whole eMMC bit is laced with why-dont-you s
rockpi can not boot from nvme