GCU(4)

💅 GCU(4) — the Intel EP80579 Global Configuration Unit, bestie edition ✨

okay so real talk, this is a Kernel Interfaces Manual page, and it's about the gcu driver — Intel EP80579 Global Configuration Unit. yes it's a mouthful, no we're not changing it. 🎀

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🌸 SYNOPSIS 🌸

gcu* at pci?

that's it. that's the whole vibe check. it attaches at pci? and honestly? slay. ✨

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💖 DESCRIPTION 💖

so the gcu driver is literally your plug for getting at the miibus that's hidden behind the GCU device. it's giving backstage pass energy, iykyk. 🫶 what it's actually for is controlling PHYs on embedded designs that use Intel's EP80579 chips — that's the main character job, periodt.

the GCU also hands out access to CAN, SSP and TDM signal strength drivers, which sounds iconic in theory, but — and this is the important part, bestie — since they're not supported by OpenBSD, the driver does not provide any functionality related to them. so like, don't come for us expecting CAN things. it's not happening. no cap. 💀

lowkey a caution: those CAN/SSP/TDM bits exist on the hardware, but this driver gives you nothing for them on OpenBSD. zero. nada. fr fr.

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🦋 SEE ALSO 🦋

• em(4)
• intro(4)
• netintro(4)
• pci(4)

and if you wanna read the source material like the little researcher you are — Intel's EP80579 Datasheet: http://download.intel.com/design/intarch/ep80579/320066.pdf 📚

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🎀 HISTORY 🎀

the gcu driver first appeared in OpenBSD 4.7. a little retro, a little vintage, still eating. 💅

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👑 AUTHORS 👑

the gcu driver was written by Dariusz Swiderski <dms@openbsd.org>, partially based on the FreeBSD driver released by Intel under the ISC license. we love a credited queen. 🫶

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and that's the whole page, bestie — no crumbs left behind 🍓

this lil fandom moment was brought to you on the Debian side of things, dated July 16, 2013 — GCU(4), signing off. 🦋✨