[yocto] kernel fragment not applied while other fragments are applied

[Mircea Gliga]

Hi

Short story: I'm using rocko and have a recipe for Linux kernel 4.14.14 
based on linux-yocto.inc, some kernel fragments end up in the resulting 
.config, other don't, if regenerate fragments using menuconfig + 
diffconfig seems ok.

Long story:
In my recipe linux-stable_4.14.bb I have an inc file:
     [...]
     require linux-stable.inc
     [...]

linux-stable.inc :

     inherit kernel
     require recipes-kernel/linux/linux-yocto.inc
     [...]
     SRC_URI += "file://defconfig \
                 file://kernel_fragments/netfilter.cfg \
                 file://kernel_fragments/overlayfs.cfg \
                 file://kernel_fragments/verity.cfg \
                 file://kernel_fragments/squashfs.cfg \
                 file://kernel_fragments/modem.cfg \
                 file://kernel_fragments/led_oneshot.cfg \
                 file://kernel_fragments/ipsec.cfg \
                 file://kernel_fragments/netbridge.cfg \
                 file://kernel_fragments/atmel_hw_sha.cfg \


I have a set of kernel fragments. During `bitbake linux-stable -c 
kernel_configme -f` some of them end up in the .config file while others 
don't:
led_oneshot.cfg and overlayfs.cfg are not applied in the resulting 
.config while verity.cfg is applied.
They are all generated using menuconfig to config the kernel, then 
diffconfig to generate the fragment.

$ cat led_oneshot.cfg
CONFIG_LEDS_TRIGGER_ONESHOT=y

$ cat verity.cfg
CONFIG_MD=y
# CONFIG_BLK_DEV_MD is not set
# CONFIG_BCACHE is not set
CONFIG_BLK_DEV_DM_BUILTIN=y
CONFIG_BLK_DEV_DM=y
# CONFIG_DM_MQ_DEFAULT is not set
# CONFIG_DM_DEBUG is not set
CONFIG_DM_BUFIO=y
# CONFIG_DM_DEBUG_BLOCK_MANAGER_LOCKING is not set
CONFIG_DM_CRYPT=y
# CONFIG_DM_SNAPSHOT is not set
# CONFIG_DM_THIN_PROVISIONING is not set
# CONFIG_DM_CACHE is not set
# CONFIG_DM_ERA is not set
# CONFIG_DM_MIRROR is not set
# CONFIG_DM_RAID is not set
# CONFIG_DM_ZERO is not set
# CONFIG_DM_MULTIPATH is not set
# CONFIG_DM_DELAY is not set
# CONFIG_DM_UEVENT is not set
# CONFIG_DM_FLAKEY is not set
CONFIG_DM_VERITY=y
# CONFIG_DM_VERITY_FEC is not set
# CONFIG_DM_SWITCH is not set
# CONFIG_DM_LOG_WRITES is not set
# CONFIG_DM_INTEGRITY is not set

$ cat overlayfs.cfg
CONFIG_OVERLAY_FS=y
# CONFIG_OVERLAY_FS_REDIRECT_DIR is not set
# CONFIG_OVERLAY_FS_INDEX is not set

$

Now, if I go in menuconfig I can see that CONFIG_OVERLAY_FS is indeed 
not enabled, I then enable it and generate a new fragment, 
fragmentOverlay.cfg:
$ cat fragmentOverlay.cfg
CONFIG_OVERLAY_FS=y
# CONFIG_OVERLAY_FS_REDIRECT_DIR is not set
# CONFIG_OVERLAY_FS_INDEX is not set

$ md5sum *verlay*
14f88a8b2dcb256c38f6362161045831  fragmentOverlay.cfg
14f88a8b2dcb256c38f6362161045831  overlayfs.cfg

The new fragment is identical to the overlayfs.cfg (which is not applied).
I let both files in the SCR_URI:

SRC_URI += "[...]
                 file://kernel_fragments/overlayfs.cfg \
                 file://kernel_fragments/fragmentOverlay.cfg \
                 [...]"

And now after `bitbake linux-stable -c kernel_configme -f` the resulting 
.config has the overlay_fs enabled:

$ cat .config | grep OVERLAY_FS
CONFIG_OVERLAY_FS=y
# CONFIG_OVERLAY_FS_REDIRECT_DIR is not set
# CONFIG_OVERLAY_FS_INDEX is not set

$ cat .config |grep CONFIG_LEDS_TRIGGER_ONESHOT
# CONFIG_LEDS_TRIGGER_ONESHOT is not set


Same contents in the fragments, one is applied while the other is not ...

Do you have any hints ?

Thanks and regards!