Script uses arbitrary values for FAT32 partition and name of the
distribution. Using placeholders in the script and replacing them at
build time offers flexibility, i.e. no need to change arbitrary values
in script when SYSTEM_SIZE is changed.
Avoid using "freeze" method, which is used by systemd in case default "mem" method fails.
"freeze" type suspend can't be woken from using IR remote and Crust firmware
on Allwinner boards.
This allows us to use the default debug-shell.service provided
by systemd and cut down on custom made services. This will also
always provide a debug shell as there is no reason we shouldn't
have access to one.
