BOOTC-LOAD...-FOR-SOURCE(8)

🌸 BOOTC-LOAD...-FOR-SOURCE(8) — aka bootc-loader-entries-set-options-for-source 🌸

okay bestie, sit down, hydrate, because this one is a system manager's page and we're getting into it 💖

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✨ NAME ✨

bootc-loader-entries-set-options-for-source — set or update the kernel arguments owned by a specific source 🫶

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✨ SYNOPSIS ✨

bootc loader-entries set-options-for-source --source NAME [--options "KARGS"]

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✨ DESCRIPTION ✨

so basically? you're setting or updating the kernel arguments that belong to one specific source. and here's the cute part: every source's args get tracked through x-options-source-<name> extension keys sitting inside the BLS config files on /boot 🎀

the options line gets recomputed as the merge of all tracked sources plus any untracked (pre-existing) options. like, everyone shows up to the group chat, nobody gets left on read 💅

this command stages a new deployment with your updated kernel args. meaning: nothing happens right now. changes take effect on the next reboot. it's giving "I'll do it tomorrow" but for real this time 🌈

and if a staged deployment already exists (say, from bootc upgrade)? it gets replaced using the staged deployment's commit and origin — so the pending upgrade stays pending, we're just layering the kargs change on top like a cute little cardigan ✨

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✨ OPTIONS ✨

• --source=SOURCE — the name of the source that owns these kernel arguments. gotta name your source bestie, it's how we know whose kargs these are 👑
• --options=OPTIONS — the kernel arguments to set for this source. these are the actual KARGS you're assigning 💜

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✨ REQUIREMENTS ✨

listen, this is the important part, no skipping 🙈

this command needs ostree >= 2026.1 with bootconfig-extra support, because that's what preserves extension BLS keys through staged deployment roundtrips. slay.

on older ostree versions, bootc loader-entries is unavailable. not deprecated, not hidden-ninja-mode, just unavailable:

• it's omitted from bootc --help (ghosted, literally)
• invoking it — including with --help — prints an error and exits with status 77

and 77 is special, ok? it's distinct from usage errors (2) and other failures (1). so if you're writing a caller, you can probe for the feature by checking the exit status of:

bootc loader-entries set-options-for-source --help

exit status as vibes check. iconic. 🦋

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✨ EXAMPLES ✨

Add TuneD kernel arguments:

bootc loader-entries set-options-for-source --source tuned \
    --options "isolcpus=1-3 nohz_full=1-3"

Update TuneD kernel arguments (replaces previous values):

bootc loader-entries set-options-for-source --source tuned \
    --options "isolcpus=0-7"

Remove all kernel arguments owned by TuneD:

bootc loader-entries set-options-for-source --source tuned

(no --options? boom, cleaned out. the way that just works 😭)

Multiple sources can coexist independently:

bootc loader-entries set-options-for-source --source tuned \
    --options "nohz=full isolcpus=1-3"
bootc loader-entries set-options-for-source --source dracut \
    --options "rd.driver.pre=vfio-pci"

look at them, two sources, living their separate lives, no drama, main character energy for both 🔥

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✨ KNOWN LIMITATIONS ✨

okay so here's the lowkey cursed part 💀

source keys set by prior calls in the same boot cycle (i.e. before any reboot) get discovered by reading the staged deployment data file at:

/run/ostree/staged-deployment

if that file is missing or cannot be parsed, sources from prior calls may not be discovered, which can potentially orphan their kargs. 😭

in practice this shouldn't happen though — the file is managed by ostree and is always present when a staged deployment exists. so like, breathe. but be aware. periodt.

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✨ SEE ALSO ✨

• bootc(8)
• bootc-loader-entries(8)

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✨ VERSION ✨

v1.17.1 🎀

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and that's the whole page bestie, we ate and left no crumbs 💅✨ mwah, go reboot something. BOOTC-LOAD...-FOR-SOURCE(8) — System Manager's Manual, v1.17.1 🦋💖