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On Sun, 29 Sep 2019 11:59:00 +0100, Mick wrote: |
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> As I understand it, 'bootctl --update' can be used to update |
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> systemd-boot boot manager's menu and it is looking for bootable |
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> kernels by scanning /efi, /boot, and /boot/efi, or the directory set |
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> by passing the '--path' option to it. Manual addition of bootable |
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> kernels must be set via /loader/entries/*.conf (one file per kernel |
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> image) and then setting the default kernel to be booted in |
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> /loader/loader.conf. I find all this to be unnecessary complication |
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> for maintaining a boot manager manually, compared to using say |
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> efibootmgr. However, it is handy to be able to press 'e' to edit the |
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> default entry at boot time, or if new kernels are always stored where |
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> expected by the scripts of binary distros. |
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> |
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> For Peter's use case, OS and kernel resides on secondary disk, the |
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> solutions I can think are: |
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> |
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[snip GRUB bit] |
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> 2. Use systemd-boot. Copy each kernel from the secondary disk to |
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> /boot/EFI/ creating the corresponding /loader/entries/*.conf, adding |
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> the kernel .conf name and the OS root partition's path on the |
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> secondary disk. The root path can also/instead be included in the |
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> kernel itself (CONFIG_CMDLINE). |
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That's not how the systemd boot manager works. It is a bootable image |
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which then reads the config from /boot/loader and presents a boot menu. |
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As far as the firmware is concerned, it is always booting the same image. |
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The loader files are analogous to grub.cfg, but a thousand times simpler |
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(I may be understating that in my desire to avoid hyperbole). For |
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example, loader.conf here is |
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timeout 3 |
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default 00-* |
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This never needs to be modified, it simply boots the first entry after 3 |
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seconds. That entry here is |
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title Desktop |
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version 5.3.1-gentoo |
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linux /vmlinuz-5.3.1-gentoo |
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options root=LABEL=yooden rd.luks.uuid=luks-d879a686-39f3-4331-b35e-7744468b5ce3 rootfstype=btrfs rootflags=rw,noatime,ssd,space_cache rd.shell net.ifnames=0 init=/lib/systemd/systemd |
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initrd /intel-uc.img |
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initrd /initramfs-5.3.1-gentoo.img |
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As you can see, the only vaguely complex part is the list of kernel |
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options, and most of that is options for the root filesystem which the |
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kernel would need for any bootloader. |
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Incidentally, I use a short shell script to regenerate the menu entries |
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after a kernel change, like grub-update but the predictable orders of |
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magnitude shorter, so even that is trivial. |
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I have tried reFind and AFAIR it works in a similar way, although I |
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stopped using it as I wasn't interested in the fancy graphical boot menu. |
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-- |
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Neil Bothwick |
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Why is bra singular and pants plural? |
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