[yocto] struggling with initramfs

[Tim Hammer]

Can anyone point me to a step-by-step tutorial or simple how-to on creating
and using an initramfs with my kernel for ARM aarch64?


I have tried creating my own:
 - boot-image.bb file with IMAGE_FSTYPES = "cpio.gz".
 - local.conf has INITRAMFS_IMAGE_BUNDLE = "1"
 - linux.bbappend has INITRAMFS_IMAGE = "boot-image"

This all seems to be "correct" to the extent that bitbake linux tries to do
the right thing.

However, I get a failure in do_bundle_initramfs- "mv: cannot stat
'arch/arm64/boot/Image': No such file or directory".

To the best of my (limited) debugging abilities with Yocto, it seems like
the kernel image backup has already been run when it gets to this point and
the Image file in that directory has already been moved to Image.bak. If I
comment out the mv statement in kernel.bbclass causing the failure, the
process continues, but the initramfs does not seem to get populated or
perhaps installed into my kernel image as I get kernel panics that I have
been unable to get past.


I decided to take a different approach and try using the
core-image-minimal-initramfs recipe as INITRAMFS_IMAGE. By commenting out
the COMPATIBLE_HOST entry I am able to build a kernel for ARM aarch64. I
can even seem to boot into this initramfs- it counts down waiting for
removable media; seems to find my primary rootfs on sda3, but there is no
rootfs.img file there so says it is dropping to a shell (although I never
get a prompt...).

Thinking I could start with that recipe and work to get rid of the live
stuff and just get to a busybox prompt before trying to run my unique init
commands, I copied  core-image-minimal-initramfs.bb to my-
core-image-minimal-initramfs.bb in my layer and changed INITRAMFS_IMAGE to
"my- core-image-minimal-initramfs".
However, I obviously missed something in the configuration as I get an
error in go_bundle_initramfs again:
     kernel-source/scripts/gen_initramfs_list.sh:
                 Cannot open
'/.../linux-qoriq/4.14-r0/build/usr/my-core-image-minimal-initramfs-{machine}.cpio'

Any help would be greatly appreciated.
Thank you!
-- 

.Tim
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.yoctoproject.org/pipermail/yocto/attachments/20180703/af0ae676/attachment.html>