janrinze: well, the way is basically:
1. pmbootstrap init (select your device)
2. pmbootstrap install --disk /dev/sdX (install on USB)
3. boot pmOS
4. go to kernel source
5. run `source ~/git/pmbootstrap/helpers/envkernel.sh` (you need pmbootstrap cloned from git)
6. run `make menuconfig` here. configure how ever you want. the config is at `.output/.config`, you can place it there manually as well
7. run `make -jN` to build kernel
8. run `pmbootstrap build --envkernel linux-postmarketos-mediatek-mt81xx` to build a kernel from it
9. run `pmbootstrap sideload --host <ip of the chromebook in your network> --install-key linux-postmarketos-mediatek-mt81xx`. this will upgrade kernel over wifi, generate initramfs, generate depthcharge image and flash it