== SOLUTION to "kernel panic - not syncing: I/O error reading memory image" ===
after reading all the messages here and google, i found in /etc/initramfs-tools/conf.d/resume
which used to be the swap partition on the machine i originally made my kernel and initrd on.
I chroot into the / partition (/dev/sda5) booting from network,
mount -o rw /dev/sda5 /mnt
mount -t proc proc /proc
By changing the file
(this is my current swap partition)
all is fine again!
Hope this helps googlers