efi_capsule_supported(9)

💖 efi_capsule_supported(9) — Kernel API Manual, but make it make sense 💖

okay bestie, welcome to the efi_capsule_supported(9) page from the Kernel API Manual. this is your lowkey vibe check for firmware capsule support, and no cap, all the facts are staying right here. 🫶

✨ NAME ✨

efi_capsule_supported — does the firmware support the capsule?

🎀 SYNOPSIS 🎀

int efi_capsule_supported (efi_guid_t guid , u32 flags , size_t size ,
       int *reset );

💅 ARGUMENTS 💅

• guid — vendor guid of capsule
• flags — capsule flags
• size — size of capsule data
• reset — the reset type required for this capsule

🦋 DESCRIPTION 🦋

Check whether a capsule with flags is supported by the firmware and that size doesn't exceed the maximum size for a capsule. literally the firmware support check, periodt. ✨

bestie, important caveat: no attempt is made to check reset against the reset type required by any pending capsules because of the races involved. that's the whole note — don't read extra into it, fr fr. 🙈

🌈 SEE ALSO 🌈

• Kernel file ./drivers/firmware/efi/capsule.c
• efi_capsule_pending(9)
• efi_capsule_update_locked(9)
• efi_capsule_update(9)

xoxo, your efi_capsule_supported(9) bestie — source/version ./drivers/firmware/efi, dated October 2026 💖✨