Re: [PATCH] rootfs: run kernel-install after update-initramfs

[Srinuvasan Arjunan <srinuvasanasv@gmail.com>]

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On Wednesday, April 15, 2026 at 6:35:30 PM UTC+5:30 Jan Kiszka wrote:

On 15.04.26 14:55, srinuvasan.a via isar-users wrote: 
> From: srinuvasan <srinuv...@siemens.com> 
> 
> When efibootguard is used as the primary bootloader and 
> systemd-boot as secondary, the WIC plugin expects /boot/EFI/Linux 
> to contain a unified kernel image for first boot. 
> 

Err, where/how do you define "primary" and "secondary" EFI bootloaders? 
Note that EBG is isar-cip-core, and there we definitely do not have such 
a concept. Can you elaborate what you want to achieve? 

> Run kernel-install after update-initramfs to ensure the unified 
> kernel image is generated and placed correctly. 
> 
> Invoke kernel-install for UKI generation only when: 
> - ukify binary is available 
> - /usr/lib/kernel/install.conf exists 
> 
> Signed-off-by: Shivaschandra KL <shivasch...@siemens.com> 
> Signed-off-by: srinuvasan <srinuv...@siemens.com> 
> --- 
> meta/classes-recipe/rootfs.bbclass | 20 +++++++++++++++++--- 
> 1 file changed, 17 insertions(+), 3 deletions(-) 
> 
> diff --git a/meta/classes-recipe/rootfs.bbclass 
b/meta/classes-recipe/rootfs.bbclass 
> index a9233111..9024f006 100644 
> --- a/meta/classes-recipe/rootfs.bbclass 
> +++ b/meta/classes-recipe/rootfs.bbclass 
> @@ -14,10 +14,20 @@ ROOTFS_DISTRO ?= "${DISTRO}" 
> ROOTFS_USE_DRACUT ??= "" 
> 
> def initramfs_generator_cmdline(d): 
> - rootfs_packages = d.getVar('ROOTFS_PACKAGES') or '' 
> + rootfs_packages = d.getVar('ROOTFS_PACKAGES') or '' 
> + 
> if 'dracut' in rootfs_packages or 
bb.utils.to_boolean(d.getVar('ROOTFS_USE_DRACUT')): 
> - return "dracut --force --kver \"$kernel_version\"" 
> - return "update-initramfs -u -v -k \"$kernel_version\"" 
> + return 'dracut --force --kver "$kernel_version"' 
> + 
> + cmdline = 'update-initramfs -u -v -k "$kernel_version"' 
> + 
> + cmdline += ( 
> + '; command -v ukify >/dev/null && [ -f /usr/lib/kernel/install.conf ] 
&& ' 

Who is using ukify? No one in isar or isar-cip-core at least. Are you 
referring to an out-of-tree wic plugin with these changes? 

In-tree (Isar), we still need to enable 
meta/scripts/lib/wic/plugins/source/bootimg-efi-isar.py to generate 
UKIs. But that would be systemd-boot UKI-only, no EBG then. 

Jan


  Hi Jan,

 In our downstream project, we use a combination of EBG and systemd-boot, 
along with UKI (ukify) images.

EBG acts as the primary bootloader to enable watchdog support during early 
boot, while systemd-boot is used as a secondary bootloader to  select the 
appropriate Btrfs snapshot along with its corresponding UKI image.

If the system fails to be successfully “blessed” (e.g., due to issues 
detected during validation of a newly created Btrfs snapshot), we need a 
mechanism to fall back to a previously working snapshot and its associated 
UKI image. This fallback selection is handled by systemd-boot.

To support this flow, the WIC plugin expects /boot/EFI/Linux to contain the 
unified kernel image required for the first boot.
Therefore, we run kernel-install after update-initramfs to ensure that the 
unified kernel image is properly generated and placed in the expected 
location. 

Many thanks,
Srinu



> + 'kernel-install add "$kernel_version" "/boot/${kernel##*/}" ' 
> + '"/boot/initrd.img-$kernel_version" || :' 
> + ) 
> + 
> + return cmdline 
> 
> ROOTFS_PACKAGES ?= "" 
> ROOTFS_VARDEPS ?= "" 
> @@ -627,6 +637,10 @@ python do_generate_initramfs_setscene () { 
> } 
> 
> rootfs_generate_initramfs[progress] = 
"custom:rootfs_progress.InitrdProgressHandler" 
> +rootfs_generate_initramfs:prepend() { 
> + export kernel 
> +} 
> + 
> rootfs_generate_initramfs() { 
> if [ -n "$(sudo find '${ROOTFSDIR}/boot' -type f -name 'vmlinu[xz]*')" ]; 
then 
> for kernel in ${ROOTFSDIR}/boot/vmlinu[xz]-*; do 


-- 
Siemens AG, Foundational Technologies 
Linux Expert Center 

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