Linux – Risks involved with lazy_itable_init=1 for ext4 fs on SD card

The reason that switch_root is not working on the command line is this code in busybox:

    if (st.st_dev == rootdev || getpid() != 1) {
        // Show usage, it says new root must be a mountpoint
        // and we must be PID 1
        bb_show_usage();
    }

You are not PID 1, so you are falling through into this bb_show_usage. The implication is that the switch_root command in your initramfs init script should run switch_root with exec. i.e.

exec switch_root ...

The other issue with your "not found" errors is likely because the shared libraries needed by the executables are not found, because the initramfs root filesystem does not have them. If you can get switch_root to work with exec, then is likely the "not found" error will go away.

Short answer

The card is password-protected. (@derobert's guess is right.) And kernel modules do not provide useful pointers to this.

TL;DR:

I was suspecting this but I did not know that it's a SD-specific hardware feature; I thought that the Nokia simply encrypts the partition which I would be able to solve by action like mkdosfs /dev/sdb or such.

Too bad that:

• it seems that this function is widely unsupported by current Linux modules (not even to the point of giving an useful error). Presumably this applies to mentioned Androids as well

• the phone refuses to format the card and remove the password. You can either remove the password, but you need to know the old one, or format the card, but that will not remove the password

So maybe other firmware has option to wipe it completely, but this is another question for another forum.

Funny background note:

While I was attending to collecting the data above, my old man (user of the phone/cards, born '45), took the old-school approach and fixed the "dying" phone by cleaning it with piece of cloth and ethanol!

This magical-sealed-computer-driven-gadget age: 0 My dad: 1 ;-D

Point is that I am now able to verify that the password has been set (and compare to the "good" card). Who and how did it, will remain a mystery.