Re: [PATCH v2 10/10] meta-isar/canned-wks: Remove /boot mountpoint

["vijaikumar....@gmail.com" <vijaikumar.kanagarajan@gmail.com>]

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On Saturday, September 5, 2020 at 2:28:17 PM UTC+5:30 Henning Schild wrote:

> Hi, 
>
> i do not like this one at all. Suggesting people to hide the boot 
> partition from debian as hard as they can? If i understand it correctly. 
>

AFAIU , /boot mount-point[1] is wrong and is not needed without 
--exclude-path of /boot in rootfs partition. 
This optional mount-point serves only one purpose, i.e, to have an entry 
added in fstab or not by wic.
We were okay with saying this EFI/bootloader partition mount-point as 
/boot, since older wic
was not adding the /boot mount-point to fstab.
With this commit [2] in OE this is no longer the case.
/boot is added to fstab and at boot the system would try to mount to this 
efi partiton to /boot
directory which, if successful, will make the kernel, initrd and config 
files which were already available in /boot
of rootfs unavailable when the system is booted. I donot see --exclude-path 
for /boot in the wks file,
so this would just be wrong to have a mount-point like this. 

[1] 
https://github.com/ilbers/isar/blob/a0d6de4ac7dfb926b38cfcd44f2bc8852f2e43e3/meta-isar/scripts/lib/wic/canned-wks/sdimage-efi.wks#L5  
[2] https://github.com/openembedded/openembedded-core/commit/2376b05512ddb8c4ec3aaf1df11071f536a76bd9


> In fact the hiding is an issue that should be solved, debian should 
> know about that partition and use it correctly. 
>
> On EFI it only contains the bootloader, so such isar images will be 
> able to receive kernel updates with apt-get during their lifetime. They 
> will never be able to update the bootloader, but that might be ok. 
>
> On BIOS the story is different. These systems have the kernel in the 
> roots/boot only that kernel is never used for booting and the machines 
> will never be able to update the kernel they boot. 
>
> I always wanted to solve that but it was not too easy. The first idea 
> was just bootloader in the boot partition, like efi. But syslinux can 
> not boot files from other partitions, so we need the kernel and initrd 
> there. 
> But now with the exclude feature it might be easier. Place the 
> bootloader and config into rootfs/boot and point to the kernel initrd 
> symlinks in the config. (Done in our custom BIOS plugin) 
> And now take rootfs/boot as boot, excluding it from rootfs.


Can you point me to some code where these kind of scenarios are? I assume
these are all downstream? For downstream you could customize the wks
with neccessary /boot as mountpoint for EFI and "--exclude-path /boot" to 
achieve
what you want. I donot see the issue in removing it here.


>
> Henning 
>
> On Thu, 3 Sep 2020 00:32:47 +0530 
> Vijai Kumar K <Vijaikumar_...@mentor.com> wrote: 
>
> > In the older version of wic, the fstab entry for /boot mountpoint 
> > was skipped. 
> > However in the latest wic this is not the case. Adding a /boot 
> > mountpoint in part results in creating a fstab entry for automount. 
> > Remove it to avoid the unwanted mount which makes original contents 
> > unavailable in debian rootfilesystem. 
> > 
> > Signed-off-by: Vijai Kumar K <Vijaikumar_...@mentor.com> 
> > --- 
> > RECIPE-API-CHANGELOG.md | 17 
> > +++++++++++++++++ .../lib/wic/canned-wks/common-isar.wks.inc | 
> > 2 +- meta-isar/scripts/lib/wic/canned-wks/hikey.wks | 2 +- 
> > .../scripts/lib/wic/canned-wks/sdimage-efi.wks | 2 +- 
> > 4 files changed, 20 insertions(+), 3 deletions(-) 
> > 
> > diff --git a/RECIPE-API-CHANGELOG.md b/RECIPE-API-CHANGELOG.md 
> > index 1839770..070cde3 100644 
> > --- a/RECIPE-API-CHANGELOG.md 
> > +++ b/RECIPE-API-CHANGELOG.md 
> > @@ -246,3 +246,20 @@ by setting DEBIAN_BUILD_DEPENDS. 
> > 
> > ${S} can now be used for checking out sources without being linked 
> > implicitly with ${D} which needs to be filled explicitly in 
> > do_install as before. + 
> > +### Wic adds /boot mountpoint to fstab 
> > + 
> > +With the latest wic, /boot mount point, if any, is added to 
> > /etc/fstab. Debian +uses /boot to store the kernel and initrd images. 
> > If an image's wks file +specifies /boot mountpoint for boot 
> > partitions like EFI, the image may fail to +boot or might make the 
> > original contents of /boot unavailable after boot. +All unwanted 
> > /boot mountpoints should be removed. + 
>

Maybe I can add a bit more to
this sentence to make it clear, something like unless you know what you are 
doing.
I could add the rest of the wks entry below to highlight that /boot is not 
excluded in the first place.
 

> > +Below is an example wks entry that might cause an issue. 

> +``` 
> > +part /boot --source bootimg-efi-isar --sourceparams 
> > "loader=grub-efi" --ondisk sda --label efi --part-type EF00 --align 
> > 1024 +``` +Drop the /boot entry to avoid issues. 
> > +``` 
> > +part --source bootimg-efi-isar --sourceparams "loader=grub-efi" 
> > --ondisk sda --label efi --part-type EF00 --align 1024 +``` 
> > diff --git a/meta-isar/scripts/lib/wic/canned-wks/common-isar.wks.inc 
> > b/meta-isar/scripts/lib/wic/canned-wks/common-isar.wks.inc index 
> > c8ea4c2..e7dabd4 100644 --- 
> > a/meta-isar/scripts/lib/wic/canned-wks/common-isar.wks.inc +++ 
> > b/meta-isar/scripts/lib/wic/canned-wks/common-isar.wks.inc @@ -1,3 
> > +1,3 @@ # This file is included into 3 canned wks files from this 
> > directory -part /boot --source bootimg-pcbios-isar --ondisk sda 
> > --label boot --active --align 1024 +part --source bootimg-pcbios-isar 
> > --ondisk sda --label boot --active --align 1024 part / --source 
> > rootfs --ondisk sda --fstype=ext4 --label platform --align 1024 diff 
> > --git a/meta-isar/scripts/lib/wic/canned-wks/hikey.wks 
> > b/meta-isar/scripts/lib/wic/canned-wks/hikey.wks index 
> > 1e82f8c..840858e 100644 --- 
> > a/meta-isar/scripts/lib/wic/canned-wks/hikey.wks +++ 
> > b/meta-isar/scripts/lib/wic/canned-wks/hikey.wks @@ -3,7 +3,7 @@ # 
> > # SPDX-License-Identifier: MIT 
> > 
> > -part /boot --source bootimg-efi-isar --sourceparams 
> > "loader=grub-efi" --ondisk mmcblk1 --label efi --part-type EF00 
> > --align 1024 +part --source bootimg-efi-isar --sourceparams 
> > "loader=grub-efi" --ondisk mmcblk1 --label efi --part-type EF00 
> > --align 1024 part / --source rootfs --ondisk mmcblk1 --fstype ext4 
> > --label platform --align 1024 --use-uuid diff --git 
> > a/meta-isar/scripts/lib/wic/canned-wks/sdimage-efi.wks 
> > b/meta-isar/scripts/lib/wic/canned-wks/sdimage-efi.wks index 
> > 2afa016..e0fa7a1 100644 --- 
> > a/meta-isar/scripts/lib/wic/canned-wks/sdimage-efi.wks +++ 
> > b/meta-isar/scripts/lib/wic/canned-wks/sdimage-efi.wks @@ -2,7 +2,7 
> > @@ # long-description: Creates a partitioned EFI disk image without 
> > any swap that # the user can directly dd to boot media. 
> > -part /boot --source bootimg-efi-isar --sourceparams 
> > "loader=grub-efi" --ondisk sda --label efi --part-type EF00 --align 
> > 1024 +part --source bootimg-efi-isar --sourceparams "loader=grub-efi" 
> > --ondisk sda --label efi --part-type EF00 --align 1024 part / 
> > --source rootfs --ondisk sda --fstype ext4 --label platform --align 
> > 1024 --use-uuid 
>
>

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