MGB(4)

🦋 MGB(4) — bestie edition, from the Kernel Interfaces Manual 🦋

okay so picture this: you've got a cute little Microchip NIC and you want FreeBSD to notice it. that's the whole vibe of mgb(4), the Microchip LAN743x PCIe Gigabit Ethernet driver. pull up a chair, we're getting into it 💅

✨ NAME ✨

mgb — the Microchip LAN743x PCIe Gigabit Ethernet driver. that's her. that's the whole name. iconic of her honestly 🎀

✨ SYNOPSIS ✨

so if you want the driver to load as a module at boot time (and bestie, that's the whole game here), you drop this line into loader.conf(5):

if_mgb_load="YES"

that's it. that's the line. put it in the file, go to bed, wake up with networking. 🫶

✨ DESCRIPTION ✨

hiii okay so real talk first: the mgb driver is experimental, and it comes with a bunch of caveats and limitations — we'll get to those down in CAVEATS, don't skip ahead too fast 🙈. also it's currently available only as a kernel module. no built-in version, sorry bestie.

now the fun part: the mgb device driver provides support for PCIe Gigabit Ethernet adapters based on Microchip's LAN7430 and LAN7431. slay.

and if you wanna actually configure this device once it's up? go read ifconfig(8). that's your girl for the setup part 💖

✨ HARDWARE ✨

the mgb driver supports Microchip PCIe Gigabit Ethernet interfaces, and the roster is literally:

• Microchip LAN7430 PCIe Gigabit Ethernet controller with PHY
• Microchip LAN7431 PCIe Gigabit Ethernet controller with RGMII interface

two icons. no notes. 👑

✨ SEE ALSO ✨

go read your friends too, iykyk:

• arp(4)
• miibus(4)
• ifconfig(8)

✨ CAVEATS ✨

okay this is the part where we're honest with each other. 🙈

the driver does not yet implement support for many hardware features, including:

• Multiple RX queue support
• RX and TX checksum offload
• Hardware VLAN tagging or untagging
• Multicast receive packet filtering
• Wake on LAN (WoL)
• LSO
• RSS

and one more thing that's lowkey important: LAN7431 support is completely untested. like, nobody has vibe-checked it. not even once. 😭 so if you're running a LAN7431, you are the main character and also the test subject. godspeed 🧚

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and that's the page bestie!! this one's from Debian, dated September 28, 2021 — that's the source/version-and-date combo, go off 💜 ✨ 🌈