[prev in list] [next in list] [prev in thread] [next in thread] 

List:       fedora-devel-list
Subject:    Re: future of dual booting Windows and Fedora, redux
From:       Lennart Poettering <mzerqung () 0pointer ! de>
Date:       2022-07-28 20:14:54
Message-ID: YuLuPh1dTeFyYqSA () gardel-login
[Download RAW message or body]

On Do, 28.07.22 13:05, Gregory Bartholomew (gregory.lee.bartholomew@gmail.com) wrote:

> VFAT-formatted version of the partition somewhere and perhaps leave the old
> one as a (temporary) failback. Besides the bootloader itself, all that is
> really on the /boot partition is the kernel and initramfs right?

Pretty much, yes.

> Also, this might be a little off-topic, but I've recommend that people use
> systemd-boot when trying to dual-boot Windows before:
> https://ask.fedoraproject.org/t/dual-booting-windows-10-and-fedora-34/14158/2
> The user reported that they were happy with that solution later on in that
> thread, but one annoyance I have is that it requires setting a
> "SYSTEMD_RELAX_XBOOTLDR_CHECKS" variable before running "bootctl install".
> Is that really necessary? Why does the /boot partition require a distinct
> GPT type code?

The boot loader needs a way to find the file systems to look into. It
does so by scanning the GPT table, to find a suitable partition, and
the GPT partition type we use is the indicator for "suitable"
partition.

Note that the sdboot from UEFI mode has no access to your /etc/fstab,
i.e. it doesn't know that you might mount some generic partition to
/boot/. Thus it needs another way to recognize the partition. That's
why you have to set the GPT partitoin type to XBOOTLDR.

> The /boot partition existed long before GPT and its type
> codes, so this seems a strange requirement (having a separate /boot was a
> common practice decades ago because the older BIOSes couldn't bootloaders
> that were placed beyond cylinder 1024 on the disk; it was also common to
> format /boot with FAT back then because syslinux liked to use that). I'd
> like to request that systemd-boot "automatically" accept/recognize a merged
> ESP+XBOOTLDR partition without having to set that special variable.

sd-boot looks for menu items in the ESP, as well as the XBOOTLDR
partition, if it exists. There's no need to "merge" ESP with XBOOTLR,
because everything you could place in XBOOTLDR you can as well put in
the ESP *anyway* if space permits it, since sd-boot checks both
place. (The reverse is not true however, certain specific things can only be
placed on the ESP, and not in XBOOTLDR, most prominently any fs
drivers that are needed to access the XBOOTLDR partition should it not
be VFAT)

Lennart

--
Lennart Poettering, Berlin
_______________________________________________
devel mailing list -- devel@lists.fedoraproject.org
To unsubscribe send an email to devel-leave@lists.fedoraproject.org
Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/
List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines
List Archives: https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org
Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure

[prev in list] [next in list] [prev in thread] [next in thread]