Karl:
> I have used busybox init for a while. It differs from sysvinit
> by not having runlevels, except perhaps on and off.
...
> One could possible (not tested) mimic sysvinit bootup by having
> for i in /etc/rc2.d/S*; do $i start; done
> in the rcS file or if you prefer you can have your own handwritten
> and tuned script there.

With this temporary fix:
mv /usr/lib/x86_64-linux-gnu/libpcre2-* /lib/x86_64-linux-gnu/
mv /usr/lib/x86_64-linux-gnu/libpcre2-* /lib/x86_64-linux-gnu/
mv /usr/lib/x86_64-linux-gnu/libblkid.so.1* /lib/x86_64-linux-gnu/
mv /usr/lib/x86_64-linux-gnu/libmount.so.1* /lib/x86_64-linux-gnu/
mv /usr/lib/x86_64-linux-gnu/uui /lib/x86_64-linux-gnu/
ldconfig

static busybox compiled from git and installed in /busybox
and theese files:
# cat inittab
::sysinit:/etc/rcS

::respawn:/sbin/agetty --noclear 38400 tty1 linux
tty2::respawn:/sbin/agetty --noclear 38400 tty2 linux
tty3::respawn:/sbin/agetty --noclear 38400 tty3 linux
tty4::respawn:/sbin/agetty --noclear 38400 tty4 linux
tty5::respawn:/sbin/agetty --noclear 38400 tty5 linux
tty6::respawn:/sbin/agetty --noclear 38400 tty6 linux

::ctrlaltdel:/busybox/poweroff
::shutdown:/busybox/swapoff -a
::shutdown:/busybox/umount -a -r
::restart:/busybox/init
# cat rcS
for i in /etc/rcS.d/S*
do
$i start
done

for i in /etc/rc2.d/S*
do
$i start
done

my test chimaera system boots just fine with init=/busybox/init.

Regards,
/Karl Hammar