during a gentoo install from the livedvd, there's one step to create a dev dir to be used later in the chroot of the target for the instalation
it's done like that
mount --rbind /dev /mnt/gentoo/dev
in the middle of the installation i decided to start over... so i just did
rm -fr /mnt/gentoo/*
thinking nothing of it ("will just unpack the stage3 tar ball again") i deleted most of the device files from my actual /dev since the ones in the chroot would be just binded to the real devices.
now, the easy solution is: reboot. i know that if I reboot they will be there again. But this is a livedvd with no persistence. So if I reboot i will lose ~1h of preparation with firmwares and whatnot,
for now i will reboot. But i'd like to learn how to restore a /dev if a case like this does happen again (and because now i need to know even if i will never use it again)
update: just remembered about LFS. reading the linux from scratch docs, i think the simplest fix is to call
most of the files seems to be there now.