[yocto] Can't boot to initramfs

Thu Jul 11 23:22:51 PDT 2019

Hey,

The only thing I can add to what I already said is my
"core-image-minimal-initramfs.bbappend":
PACKAGE_INSTALL += "\
                         busybox \
                         base-files \
                         base-passwd \
                         bash \
                         util-linux-lsblk \
                         vim \
                         "
Jupiter, are you able to produce your zImage-initramfs now ? If not
further do the following:

bitbake <your-image> -e > tempfile
[wait until done, then search]
grep <appropriate search word> tempfile

where <appropriate search word> may be e.g.: zImage, zImage-initramfs,
INITRAMFS_IMAGE, INITRAMFS_IMAGE_BUNDLE
Especially check that all variables you set are not overwritten
somewhere else

Best regards
Moritz

On 12.07.19 06:36, Zoran Stojsavljevic wrote:
> Moritz,
>
> Thank you very much for this reply. It makes it very clear... What is
> the current State of Affairs for the topic.
>
> Let us see if there will be the improvement to this topic. I'll
> document this on one of my private GitHubs. And archive this email.
>
> Zoran
> _______
>
> On Thu, Jul 11, 2019 at 12:39 PM Moritz Porst <moritz.porst at gmx.de> wrote:
>> Hello Zoran, Jupiter and list
>>
>> The configuration you sent seems to be correct.
>>
>> As I already said initramfs seems overly complicated in yocto. the most
>> important thing to note is that 2 kernel images are created, one is
>> called bzImage (in my case) an the other bzImage-initramfs. However only
>> the bzImage is written into the rootfs so you have to exchange them
>> manually. (in /boot/bzImage). I did not find a way of including the
>> bundled kernel right away.
>>
>> What you can do is to build core-image-minimal-initramfs and delete the
>> symbolic link "bzImage", then recreate it and let it point to
>> bzImage-initramfs. However this is rather a hack than a solution.
>>
>> An other mistake I made was to use IMAGE_INSTALL_append which is
>> ignored. Use PACKAGE_INSTALL_append.
>>
>> Also I found that "break" does not work as a kernel parameter. Use
>> "shell" oder "debug-shell" instead. If you want to try to boot into
>> initramfs you can remove all parameters to the booting line so you
>> either end up in a kernel panic (initramfs doesn't work) or in the
>> rescue shell (initramfs works).
>>
>> In the end I actually managed to get a working shell, but I often ended
>> up in initramfs telling me "dropping to shell..." but then freezing.
>>
>> I don't have access to my files right now but I can tell you more on my
>> setup tomorrow. In case the solution is not included above.
>>
>> Best regards
>> Moritz
>>
>> On 11/07/2019 09:24, Zoran Stojsavljevic wrote:
>>> Hello Moritz,
>>>
>>> I need here some help from you. I'll try to reconstruct the parts of
>>> the local.conf you are using, so I (and Jupiter) can understand what
>>> should we do to also bundle kernel image with initramfs, to end up in
>>> Dracut/rescue shell.
>>>
>>> Here is what I anticipate after reading several YOCTO @ threads:
>>>
>>> IMAGE_FSTYPES_append = " cpio.gz"
>>> INITRAMFS_IMAGE = "core-image-minimal-initramfs"
>>> INITRAMFS_IMAGE_BUNDLE = "1"
>>> # debug: adds debug boot parameters like 'shell' and 'debug', see
>>> # meta/recipes-core/initrdscripts/initramfs-framework/debug for details
>>> # Could be removed in more minimal product image
>>> PACKAGE_INSTALL += "initramfs-module-debug"
>>>
>>> Could you, please, review these lines and fix, if something is not correct?
>>>
>>> I what I understood, this does the magic, but you could not stop in
>>> initramfs shell? Still, this problem is not solved?
>>>
>>>> I was following this site: https://wiki.debian.org/InitramfsDebug
>>>> Rescue shell (also known as initramfs shell)
>>>> Read man initramfs-tools to learn about the break=something kernel
>>>> parameter (where valid arguments for something are: top, modules,
>>>> premount, mount, mountroot, bottom, init), which starts a debug shell.
>>>> You can try, for example, break=premount. You can edit /boot/grub/grub.cfg
>>>> to add this to the end of the kernel line, or you can do it interactively
>>>> from the grub boot menu: "e" to edit, and "b" to boot once you've edited
>>>> the kernel line.
>>> Now, as my understanding is, you solved this problem actually adding
>>> to grub.cfg in command kernel line break=premount, and was able to
>>> stop in rescue shell?! Am I correct here?
>>>
>>> Thank you,
>>> Zoran
>>> _______
>>>
>>>
>>> On Mon, Jul 1, 2019 at 4:33 PM Moritz Porst <moritz.porst at gmx.de> wrote:
>>>> Hello,
>>>> I think I found the issue. ( see below )
>>>>
>>>> On 01.07.19 15:57, Zoran Stojsavljevic wrote:
>>>>
>>>> Hello Moritz,
>>>>
>>>> Too hot here, in Belgrade... Where I am resting for the Time being
>>>> (actually, this message given to my invisible spying security "angels"
>>>> on this list)...  :-) Projected +38C degrees today. Too hot for this
>>>> too old Siberian untouchable bobcat!
>>>>
>>>> Luckily it's a rather cold day in germany, thanks that you still take the time to answer !
>>>>
>>>> I started from the core-image-minimal to have a small image and
>>>> extended it with the features I need, which is e.g. a graphical system.
>>>> The console=[...] part in the kernel command line is probably a
>>>> remnant but my image boots into the GUI. Is this a problem ?
>>>>
>>>> Nope, it is not. If you need to do it correctly, you should use
>>>> bitbake -k core-image-sato build command (my best educated guess).
>>>> Then, I do not feel comfortable seeing in your kernel command line
>>>> serial interface, do you agree?
>>>>
>>>> Yes that is true.
>>>>
>>>> YOCTO maintainers, any additional
>>>> advices?
>>>>
>>>> My bootloader is currently grub, the EFI is AM.
>>>>
>>>> Nope. Eeeeeeeeek. Wrong. Currently, your boot-loader is UEFI AMI. Your
>>>> OS (Linux probably, U name it) boot-loader is GRUB2. Let us keep it
>>>> contained, sane and sober.
>>>>
>>>> Sorry but I can't find this info in the EFI.
>>>>
>>>> Could you, please try the following command being root: dmesg | grep
>>>> MCU. or grep mcu, or grep CPUID or grep cpuid?? Please, post results
>>>> to this list (to me).
>>>>
>>>> No luck unfortunately (used grep -i)
>>>>
>>>> Could you, also, send to YOCTO list/me attached file:
>>>> /boot/microcode.cpio so I can somehow (?) inspect it? ;-)
>>>>
>>>> I send it to you directly, so I don't spam the list with a large attachment.
>>>>
>>>> 2GB, single channel.
>>>>
>>>> All Cool. E3825 by HW/silicon design could/does NOT support multiple
>>>> memory channels. ONLY single... But even YOCTO primes (INTEL ones from
>>>> this list) are not gonna tell this to you. Not 'cause they are nasty.
>>>> They are NOT aware/they are ignorant (with the purpose)! ;-))
>>>>
>>>> No, the boot does not stop. Even if I do issue "break=premount" I
>>>> end up in my graphical interface with the rootfs mounted. This is the
>>>> last message in the log: EXT4-fs (sdb2): re-mounted. Opts: (null)
>>>> The rootfs partition is always 2, so either /dev/sda2 or /dev/sdb2
>>>> (when booting from stick)
>>>>
>>>> Yes, from https://pastebin.com/ya7iCtq7, so it is remounted rw, not
>>>> read only. So, it seems that you have passed dracut phase. and mounted
>>>> SD or flash rootfs. So, initramfs is NOT your true problem, is it???
>>>>
>>>> The thing is that the boot works but I want an initramfs that can be used for updating (in case the rootfs is broken). However I need to be able to intercept the boot process there because otherwise I can't deploy an update mechanism, that's what I was trying.
>>>>
>>>> Zoran
>>>> _______
>>>>
>>>>
>>>> No, the boot does not stop. Even if I do issue "break=premount" I end up
>>>> in my graphical interface with the rootfs mounted. This is  the last message
>>>> in the log: EXT4-fs (sdb2): re-mounted. Opts: (null) The rootfs partition is
>>>> always 2, so either /dev/sda2 or /dev/sdb2 (when booting from stick)
>>>>
>>>>
>>>> So for the issue...
>>>> I expected yocto to put the bundled bzImage onto my rootfs. This was not the case. My image directory contains 2x bzImage, one bundled and one unbundled. Apparently yocto puts the >un<bundled image onto my /boot partition and uses it for boot. So of course I couldn't access initramfs in this case. Now I get to the initramfs statement "dropping to shell" if I intentionally boot with wrong rootfs.
>>>> Still I don't get the interactive shell.
>>>> On the github ostroproject site I found this:
>>>>
>>>> # debug: adds debug boot parameters like 'shell' and 'debug', see
>>>> #        meta/recipes-core/initrdscripts/initramfs-framework/debug for details
>>>> # Could be removed in more minimal product image.
>>>> PACKAGE_INSTALL += "initramfs-module-debug"
>>>>
>>>> including the module-debug still does not enable me to get an interactive shell.
>>>> I was following this site: https://wiki.debian.org/InitramfsDebug
>>>> I am aware that yocto is no debian but I expected that kernel parameters (like 'break') would be independent of the distribution.
>>>>
>>>> Lastly I do not really need the interactive shell, it is enough if I can deploy a custom init script in the initramfs. Still I think that getting an initramfs shell should be as simple as stating the name of the initramfs image and setting the "INITRAMFS_DO_BUNDLE" variable.
>>>>
>>>> Best regards
>>>> Moritz
>>>>
>>>>
>>>> On Mon, Jul 1, 2019 at 11:20 AM Moritz Porst <moritz.porst at gmx.de> wrote:
>>>>
>>>> Hello Zoran,
>>>> thanks for your answer
>>>>
>>>> On 28.06.19 14:26, Zoran Stojsavljevic wrote:
>>>>
>>>> INITRAMFS_IMAGE = "core-image-minimal-initramfs"
>>>> INITRAMFS_IMAGE_BUNDLE = "1"
>>>>
>>>> ...
>>>>
>>>> You can find the /var/log/dmesg here: https://pastebin.com/ya7iCtq7I
>>>>
>>>> Some hints...
>>>>
>>>> [1] Kernel command line: BOOT_IMAGE=/bzImage root=PARTUUID=71d1d94a-83e8-4895-98eb-35309f58119f
>>>> break=premount quiet rootwait rootwait rootfstype=ext4 console=ttyS0,115200 console=tty0
>>>>
>>>> input: Video Bus as /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/LNXVIDEO:00/input/input7
>>>> fbcon: inteldrmfb (fb0) is primary device
>>>> Console: switching to colour frame buffer device 128x48
>>>> i915 0000:00:02.0: fb0: inteldrmfb frame buffer device
>>>> snd_hda_intel 0000:00:1b.0: bound 0000:00:02.0 (ops i915_audio_component_bind_ops [i915])
>>>>
>>>> Hmmmmm... You are using console and serial, but full i915 GFX kernel driver is still included in the build???
>>>>
>>>> I started from the core-image-minimal to have a small image and extended it with the features I need, which is e.g. a graphical system. The console=[...] part in the kernel command line is probably a remnant but my image boots into the GUI. Is this a problem ?
>>>>
>>>>
>>>> [2] efi: EFI v2.31 by American Megatrends
>>>>
>>>> Using AMI BIOS as boot loader FW... OK?! Am I correct?
>>>>
>>>> My bootloader is currently grub, the EFI is AM.
>>>>
>>>>
>>>> [3] smpboot: CPU0: Intel(R) Atom(TM) CPU  E3825  @ 1.33GHz (family: 0x6, model: 0x37, stepping: 0x9)
>>>>
>>>> This is CPUID ID 0x30679, which uses MCU... Which MicroCodeUnit? M0130679xxx (info from AMI BIOS)?
>>>>
>>>> Sorry but I can't find this info in the EFI
>>>>
>>>>
>>>> [4] Using INTEL ATOM BYT E3825 dual core (sans Hyper-threading), implies that you are using
>>>> 4GB (e820 messages) as single channel (one memory module DDR3 as 4GB)! Am I correct (important)?
>>>>
>>>> 2GB, single channel.
>>>>
>>>>
>>>> [5] Dracut phase?!
>>>>
>>>> To my understanding the initramfs should be embedded in /boot/bzImage.
>>>> However since I use an intel platform I also have a /boot/microcode.cpio
>>>> which gets loaded via "initrd /microcode.cpio". Removing this line in
>>>> grub does not enable me to get an initramfs prompt either (again, using
>>>> break as option).
>>>>
>>>> You are obviously stopping in boot phase called dracut. Please, try to mount by hand
>>>> /dev/sda(whatever)... You should use fdisk -l command, or do ls -al /dev | grep sda to
>>>> dig out which partition you need to mount to /tmp dir to see rootfstype=ext4 (HDD/SSD)
>>>>
>>>> No, the boot does not stop. Even if I do issue "break=premount" I end up in my graphical interface with the rootfs mounted. This is the last message in the log:
>>>> EXT4-fs (sdb2): re-mounted. Opts: (null)
>>>> The rootfs partition is always 2, so either /dev/sda2 or /dev/sdb2 (when booting from stick)
>>>>
>>>> _______
>>>>
>>>> Just thinking loud... .. .
>>>>
>>>> Hope this helps (has very little to do with YOCTO build system, BTW) . ;-)
>>>>
>>>> Zoran
>>>> _______
>>>>
>>>>
>>>> On Fri, Jun 28, 2019 at 11:22 AM Moritz Porst <moritz.porst at gmx.de> wrote:
>>>>
>>>> Hello,
>>>> I currently try to deploy a single rootfs update mechanism for my
>>>> embedded device. I can't boot to initramfs using either "break" or
>>>> "break=premount" (without quotes...). I tried this in systemd-boot and
>>>> grub-efi (always efi boot) but the boot process just continues normally.
>>>> If I insert at the same point e.g. "quiet" this argument is recognised.
>>>> I boot the .wic image with a separate boot partition from a USB stick.
>>>> in local.conf I have set:
>>>> INITRAMFS_IMAGE = "core-image-minimal-initramfs"
>>>> INITRAMFS_IMAGE_BUNDLE = "1"
>>>>
>>>> In order to reduce complexity I now use the standard
>>>> core-image-minimal-initramfs without .bbappend. I can confirm (from
>>>> seeing the task) that bitbake bundled the kernel with the initramfs.
>>>>
>>>> You can find the /var/log/dmesg here: https://pastebin.com/ya7iCtq7
>>>>
>>>> To my understanding the initramfs should be embedded in /boot/bzImage.
>>>> However since I use an intel platform I also have a /boot/microcode.cpio
>>>> which gets loaded via "initrd /microcode.cpio". Removing this line in
>>>> grub does not enable me to get an initramfs prompt either (again, using
>>>> break as option).
>>>>
>>>> Did I forget some configuration or do I have to put the break statement
>>>> at a very specific position within the "linux ..." boot command ? Do you
>>>> know which bitbake variables to check ? (both set in local.conf do not
>>>> get overwritten, already checked this). I got the thud branch checked
>>>> out in all my meta-layers except for meta-qt which is currently on
>>>> master branch.
>>>>
>>>> Help is much appreciated !
>>>>
>>>> Best regards
>>>> Moritz
>>>>
>>>> --
>>>> _______________________________________________
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>>>> yocto at yoctoproject.org
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