Greetings!
I am trying to create a different kind of multi-boot environment and I am stuck.
First: I know this works because I tried it before with a different version of Raspbian, (the plain vanilla 32 and 64 bit versions of Raspbian).
Now I have extended this to contain
- Raspbian for Robots buster
- GoPiGo O/S 3.0
- Full up latest version of Raspberry Pi O/S 32 bit
- Full up latest version of Raspberry Pi O/S 64 bit.
Previously, except for some PARTUUID errors, (silly me!), everything was golden.
Today while trying to boot R4R for the first time I am getting as far as
mmc1: new high speed SDIO card at address 0001
random: crng init done
Without typing in the entire screen, the last few messages are:
mc1: queuing unknown CIS tuple 0x80 (3 bytes)
mmc0 SDHCI controller on fe340000.emmc2 [fe340000.emmc2] using ADMA
of_cfs_init
of_cfs_init: OK
Waiting for root device PARTUUID=0df6e72d-05
random: fast init done
mmc1: new high speed SDIO card at address 0001
random: crng init done
It has been sitting for about five minutes.
I don’t know if it’s still waiting for the root device or something else is the problem.
Any help would be gratefully appreciated.
Update:
It appears that the latest, as-released, version of Raspbian for Robots (2019-12-12 or thereabouts) does not have boot files compatible with booting directly to a USB device.  What puzzled me is that I’ve been booting R4R to a USB device for a while now - so why should R4R “suddenly” stop working?
I do not know this for a fact, but I strongly suspect that subsequent upgrades to the system since the original installation to its SD card updated the boot files and configuration to make it compatible.
Copying all the “fixup[xx]” and start[xxx].elf files from GoPiGo O/S’s boot partition to the boot partition of Raspbian for Robots, appears to “fix” the problem.
Note that I have not yet tried this with anything other than a Pi-4 4gb system.