PCN(4)

💖 PCN 💖 — like, the pcn(4) manual page, bestie

okay so this is the Kernel Interfaces Manual page for pcn, and I'm gonna walk you through it like we're texting at 2am. it's a whole driver. it's giving vintage networking. let's go 🫶

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✨ NAME ✨

pcn — the AMD PCnet/PCI Fast Ethernet device driver. that's it. that's the girl. 💅

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🌸 SYNOPSIS 🌸

so if you wanna bake this driver straight into your kernel (no cap, you can), you drop these lines into your kernel configuration file:

device miibus
device pcn

or, if you'd rather load it as a module at boot time like a chill flexible queen, put this line in loader.conf(5):

if_pcn_load="YES"

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💀 DEPRECATION NOTICE 💀

okay bestie, listen, this is important. the pcn driver is not present in FreeBSD 13.0 and later. it's gone. retired. she said bye. 😭

if you need the tea, there's more info here: https://github.com/freebsd/fcp/blob/master/fcp-0101.md

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🦋 DESCRIPTION 🦋

so the pcn driver is out here providing support for PCI Ethernet adapters and embedded controllers that are based on the AMD PCnet/FAST, PCnet/FAST+, PCnet/FAST III, PCnet/PRO, and PCnet/Home Ethernet controller chips. and the supported NICs? they include the Allied Telesyn AT-2700 family. iconic. ✨

now, the PCnet/PCI chips come with a 100Mbps Ethernet MAC and they support both a serial and an MII-compliant transceiver interface. they use a bus master DMA and a scatter/gather descriptor scheme. and the AMD chips? they give you a mechanism for zero-copy receive, which means genuinely good performance in server environments. we love a server girlie. 💖

receive address filtering? handled with a single perfect filter entry for the station address and a 64-bit multicast hash table. slay.

the pcn driver supports the following media types:

• autoselect — turns on autoselection of the media type and options. and you can manually override the autoselected mode by adding media options to rc.conf(5). so you're not stuck with what it picks, bestie.
• 10baseT/UTP — sets 10Mbps operation. and the ifconfig(8) mediaopt option can also be used to select either ‘full-duplex’ or ‘half-duplex’ modes.
• 100baseTX — sets 100Mbps (Fast Ethernet) operation. and yeah, the ifconfig(8) mediaopt option can also be used to select either ‘full-duplex’ or ‘half-duplex’ modes.

and the pcn driver supports the following media options:

• full-duplex — force full duplex operation. periodt.
• half-duplex — force half duplex operation.

for more info on configuring this device, go look at ifconfig(8). iykyk. 🌈

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👑 HARDWARE 👑

the pcn driver supports adapters and embedded controllers based on the AMD PCnet/FAST, PCnet/FAST+, PCnet/FAST III, PCnet/PRO and PCnet/Home Fast Ethernet chips:

• AMD Am79C971 PCnet-FAST
• AMD Am79C972 PCnet-FAST+
• AMD Am79C973/Am79C975 PCnet-FAST III
• AMD Am79C976 PCnet-PRO
• AMD Am79C978 PCnet-Home
• Allied-Telesis LA-PCI

a whole roster. main character energy for real. 🔥

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🔥 DIAGNOSTICS 🔥

okay this is the part where the driver talks to you. here's what each message means:

• pcn%d: couldn't map ports/memory — a fatal initialization error has occurred. it's bad, bestie. 💀
• pcn%d: couldn't map interrupt — a fatal initialization error has occurred. also bad. 😭
• pcn%d: watchdog timeout — the device has stopped responding to the network, or there's a problem with the network connection (e.g. a cable fault).
• pcn%d: no memory for rx list — the driver failed to allocate an mbuf for the receiver ring.
• pcn%d: no memory for tx list — the driver failed to allocate an mbuf for the transmitter ring when allocating a pad buffer or collapsing an mbuf chain into a cluster.
• pcn%d: chip is in D3 power state -- setting to D0 — now THIS one, listen up, it only applies to adapters which support power management. some operating systems place the controller in low power mode when shutting down, and some PCI BIOSes fail to bring the chip out of this state before configuring it. the controller loses all of its PCI configuration in the D3 state, so if the BIOS does not set it back to full power mode in time, it will not be able to configure it correctly. the driver tries to detect this condition and bring the adapter back to the D0 (full power) state, but this may not be enough to return the driver to a fully operational condition. if you see this message at boot time and the driver fails to attach the device as a network interface, you will have to perform a warm boot to have the device properly configured. 😤

note that this condition only occurs when warm booting from another operating system. if you power down your system prior to booting FreeBSD, the card should be configured correctly. so like… just power cycle, bestie. 🧚

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💜 SEE ALSO 💜

arp(4), miibus(4), netintro(4), ng_ether(4), ifconfig(8)

also: AMD PCnet/FAST, PCnet/FAST+ and PCnet/Home datasheets, at http://www.amd.com. go read them if you're that kind of nerd (affectionate). 📚

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🌟 HISTORY 🌟

the pcn device driver first appeared in FreeBSD 4.3. a true elder. respect her. ⭐

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🎀 AUTHORS 🎀

the pcn driver was written by Bill Paul <wpaul@osd.bsdi.com>. thank you king, we owe you everything. 🙈

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and that's the whole page, bestie!! this one came out of the Debian source, dated October 24, 2018 — so that's the version and the date, all wrapped up in a little bow for you. 🎀💖✨