package/systemd: enable tmpfs kernel option
systemd automatically creates tmpfs mounts for /tmp, /run, /dev/shm, and
others. If tmpfs is not enabled in the kernel, systemd crashes with an
unknown filesystem error on boot. This hasn't manifested itself during
tests with defconfigs such as pc_x86_64_efi_defconfig for a few reasons:
- No defconfig uses systemd as the init system by default
- Even if a user does use pc_x86_64_efi_defconfig and changes to systemd,
the board/pc/linux.config file enables CONFIG_PCI, which selects
CONFIG_TMPFS.
- The systemd init tests use a prebuilt kernel with tmpfs enabled.
Enable tmpfs unconditionally to ensure that systemd always boots, even with
a minimal kernel built.
Signed-off-by: Adam Duskett <adam.duskett@amarulasolutions.com>
Signed-off-by: Julien Olivain <ju.o@free.fr>