Some kernels, for example linux-yocto 3.19 for qemux86, fail to
execute /init in an initramfs unless there is already a /dev/console
char device in the initramfs. Booting then fails with:
Kernel panic - not syncing: /dev/console is missing or not a character device!
Please ensure your rootfs is properly configured
The panic itself comes from a linux-yocto specific patch to
kernel_init_freeable in init/main.c, but even without it, that
function will print an error when /dev/console is missing. The
kernel's Documentation/initrd.txt also mentions creating that device.
It remained unclear why this is not a problem on other machines. On
intel-corei7-64 from meta-intel, something (the kernel?) creates
/dev/console and /dev/[012] before transfering control to the init
script. In that case, creating /dev/console in advance is not
necessary, but does not cause any problem either.
Signed-off-by: Patrick Ohly <patrick.ohly@intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
