mp_register_ioapic(9)

💖 mp_register_ioapic(9) 💖

okay so bestie, welcome to the mp_register_ioapic page from the Kernel API Manual 🎀 — yes that's the manual name, we're in the kernel-API girlies now, and this one is literally about telling the kernel "hey, there's a new IOAPIC here, pls add it to the roster" ✨

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✨ NAME ✨

mp_register_ioapic — Register an IOAPIC device 🦋

like, that's it, that's the whole job: you hand over a device and it goes on the list. iconic behaviour, no cap 💅

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✨ SYNOPSIS ✨

int mp_register_ioapic (int id , u32 address , u32 gsi_base , struct ioapic_domain_cfg *cfg );

that's the whole vibe check right there — one call, four things to feed it, and it gives you back an int 🫶

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✨ ARGUMENTS ✨

• id — the hardware IOAPIC ID 🌸 like, which IOAPIC this actually is, hardware's own little name tag for it, iykyk
• address — the physical address of IOAPIC register area 📍 the literal spot in physical memory where you go poke its registers, don't lose it
• gsi_base — the base of GSI associated with the IOAPIC ⭐ the starting GSI number this device owns, so everybody knows where its interrupt neighbourhood begins
• cfg — the configuration information for the IOAPIC 🧚 a struct ioapic_domain_cfg *, and honestly the struct name is doing main character energy all on its own

ngl bestie, four arguments, zero defaults, zero optional ones — you're bringing all of them to the function or you're not coming at all 💀

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✨ SEE ALSO ✨

• Kernel file ./arch/x86/kernel/apic/io_apic.c — the actual source file, go read it, it's giving lore 🔥
• disable_ioapic_support(9) — the other one, the "turn it off" one, opposite energy fr fr 👑

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and that's the page!! 🌈 this absolute gem comes to you from the source ./arch/x86/kernel/apic and it's dated October 2026 🎀 slay, stay registered, and go touch some GSI bases 💜🦋