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Welcome to the kexec_uefi wiki!

Goal

As UEFI PE format kernel image is more popular, it urges a bailout to kexec reboot those kinds of images.

That method should support various PE format, an ideal way is to obey UEFI specification. As a result efi-stub and the method communicate through UEFI specification, which is more reliable.

exception

The purpose is to support the uefi compatible image or boot-chain image in case of kexec reboot or kdump. It does only need to implement a minimum set of UEFI support. So it is critical to define the boundary of this minimum subset.

requirements

Some requirements from the existing efi-stub

• GRUB needs block I/O
• systemd-stub/UKI needs file I/O to look for sidecars
• zboot

The challenges:

TPM device drivers the stub's execution can not change the system's state unexpected by linux kernel