I am not familiar with the MCHD as I only have a few MCH. I assume the “firmware” partitions are in eMMC for MCHD while they are on disk for the MCH.
Anyways, I went a different route and disabled the fw_verify in the system_init found under /scripts/ in the image.cfs (New software - #41 by zeusjan)
You just have to make sure to replace the correct image.cfs as there are two paritions holding the last two fw updates (for MCH its /dev/sataa19 and /dev/sataa20).
The partition with the most recent change date is the one the device is probably currently using.
I took the sshd from Debian Bullseye for aarch64 (ARM). The public key has to use ed25519 .
I am now logged on via SSH. Here is the reason why you’re being asked for a password over Serial:
cat /etc/inittab
# This is run first except when booting in single-user mode.
::sysinit:/etc/rc.sh
# /bin/sh invocations on selected ttys
#
# Must be first 'respawn' entries to avoid ^C problem
# Start a shell on the console
#::respawn:-/bin/sh
ttyS0::askfirst:/bin/login
#ttyS0::respawn:/sbin/getty 115200 ttyS0
#tty2::respawn:/sbin/getty 9600 tty2
# Start an "askfirst" shell on /dev/ttyS1
#ttyS1::askfirst:-/bin/sh
Alex
