Compile Linux with initrd and cmdline baked in

gistfile1.txt

Linux initrd and cmdline bake-in (on Debian stretch)

wget https://git.kernel.org/torvalds/t/linux-4.14-rc1.tar.gz
tar xvf linux-4.14-rc1.tar.gz
cp /boot/config-4.9.0-3-amd64 .config
make oldconfig # choosing all default options is fine
make -j8 deb-pkg

sudo dpkg -i ../linux-image-4.14.0-rc1_4.14.0-rc1-1_amd64.deb
mkdir initramfs
cd initramfs
zcat /boot/initrd.img-4.14.0-rc1 | cpio -idmv
# make changes if needed
cd ..
sudo apt-get remove linux-image-4.14.0-rc1

#edit .config
CONFIG_BLK_DEV_INITRD=y
CONFIG_INITRAMFS_SOURCE="initramfs"
CONFIG_INITRAMFS_ROOT_UID=1000 <--- make sure it matches current owner of the initramfs folder
CONFIG_INITRAMFS_ROOT_GID=1000 <--- make sure it matches current owner of the initramfs folder
...
CONFIG_CMDLINE_BOOL=y
CONFIG_CMDLINE="root=/dev/sda2 ro quiet" # encoding root=UUID= path for root will break the kernel booting on other systems, make sure the disk is actually visible in fdisk -l as "sda"
CONFIG_CMDLINE_OVERRIDE=y
...
# Bake-in any other kernel modules needed here as appropriate

# recompile
make -j8 deb-pkg