
Kexecboot: Linux-As-a-Bootloader implementation based on kexec - mmastrac
https://github.com/kexecboot/kexecboot/wiki
======
zozbot234
Interesting. A kexecboot patch is widely available on Android, it gets used to
provide a hackish multi-OS functionality. (The early boot environment brings
up a multi-boot GUI, and the user can choose to continue booting or kexec a
different kernel and system image.)

~~~
joewee
Still requires installing twrp?

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kevinoid
Could anyone familiar with this project comment on how it compares to kboot
and petitboot?

[http://kboot.sourceforge.net/](http://kboot.sourceforge.net/)

[https://github.com/open-power/petitboot](https://github.com/open-
power/petitboot)

~~~
mmastrac
From a first glance, kboot seems to be unmaintained since 2007. Petitboot
looks pretty good but doesn't do x86.

Edit:
[https://www.plop.at/en/plopkexec/download.html](https://www.plop.at/en/plopkexec/download.html)
might be a better alternative!

~~~
kenz0r
Petitboot does do x86 - we're using it on an AMD x86-64 network appliance.

[https://opengear.com/products/om2200-operations-
manager/](https://opengear.com/products/om2200-operations-manager/)

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jay7x
Hi there! I'm one of kexecboot contributors. Just realized it's > 11 years old
already! We're not active for last years but we're still alive. Feel free to
adopt kexecboot to your device and make PR back! Thank you for raising
attention too :)

\-- Jay7x

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spease
Is there a way to write a kernel directly to a boot sector and boot directly
from it?

~~~
tsuraan
Somewhat; if your system boots through EFI (as opposed to the ancient BIOS
boot), then you can compile your kernel with the EFI_STUB option[0]. That
kernel can be placed in EFI/Boot/bootx64.efi (or whatever you've configured
your EFI to boot), and the EFI boot loader will run it without any other boot
loader. IME, this goes very well with a built-in initramfs
(INITRAMFS_SOURCE[1]), so you have a single-file kernel and ramfs that boots
directly from EFI.

[0] - [https://www.kernel.org/doc/html/latest/admin-guide/efi-
stub....](https://www.kernel.org/doc/html/latest/admin-guide/efi-stub.html)
[1] -
[https://github.com/torvalds/linux/blob/master/Documentation/...](https://github.com/torvalds/linux/blob/master/Documentation/driver-
api/early-userspace/early_userspace_support.rst)

~~~
Boulth
That's right. I'm using this kind of setup on Arch (including Secure Boot
signing of the EFI kernel).

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ewwhite
I've been using _this_ kexec-reboot utility for years.

[https://github.com/error10/kexec-reboot](https://github.com/error10/kexec-
reboot)

