[OE-core] [PATCH 3/8] initramfs-live-boot: create /dev/console

[Patrick Ohly]

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 at intel.com>
---
 meta/recipes-core/initrdscripts/initramfs-live-boot_1.0.bb | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/meta/recipes-core/initrdscripts/initramfs-live-boot_1.0.bb b/meta/recipes-core/initrdscripts/initramfs-live-boot_1.0.bb
index b54cb61..57b3025 100644
--- a/meta/recipes-core/initrdscripts/initramfs-live-boot_1.0.bb
+++ b/meta/recipes-core/initrdscripts/initramfs-live-boot_1.0.bb
@@ -11,9 +11,11 @@ S = "${WORKDIR}"
 
 do_install() {
         install -m 0755 ${WORKDIR}/init-live.sh ${D}/init
+        install -d ${D}/dev
+        mknod -m 622 ${D}/dev/console c 5 1
 }
 
-FILES_${PN} += " /init "
+FILES_${PN} += " /init /dev "
 
 # Due to kernel dependency
 PACKAGE_ARCH = "${MACHINE_ARCH}"
-- 
2.1.4