pdc_chassis_send_status(9)

📦 version 7.3.1, in nixpkgs unstable

💅 NAME 💅

okay so this whole page is straight out of the Kernel API Manual, and the star of the show is pdc_chassis_send_status — it sends a predefined message to the chassis, and changes the front panel LEDs according to the new system state. yes bestie, it's literally talking to the box and making the lights do their thing. iconic behavior fr fr 💖

✨ SYNOPSIS ✨

int pdc_chassis_send_status (int message );

no cap, that's the whole signature. one argument, one int coming back at you 🫶

🎀 ARGUMENTS 🎀

  • message — the type of message you're sending, and it has to be one of the PDC_CHASSIS_DIRECT_* values. that's the vibe check for this parameter, no other values slay here 💅

🦋 DESCRIPTION 🦋

okay so the support situation is a little exclusive, and honestly it's giving VIP list energy: only machines with 64 bits PDC PAT and those reported in pdc_chassis_checkold are supported atm. so if your box isn't on that list, it's not getting in, sorry babe 😭

now for the return values, because yes we care about those:

  • returns 0 if there's no error (slay, we love a clean run ✨)
  • returns -1 if no supported PDC is present or the message is invalid (rude, but fair 💀)
  • otherwise it returns the appropriate PDC error code, so you know exactly what went sideways

and if you're sitting there like "bestie what are the predefined messages tho", for a list of predefined messages, see asm-parisc/pdc_chassis.h — that's where the whole squad lives 🧚

💖 SEE ALSO 💖

the way this is a whole friend group of functions, obsessed 🫶 go read them, iykyk 🌈

lowkey reminder: this is kernel-adjacent stuff, so like… respect the return codes and don't just assume every machine is supported. the caveats above are real, not just me being dramatic 🙈

mwah 💋 this little page lives in ./arch/parisc/kernel, dated October 2026, and it's the pdc_chassis_send_status(9) manual — main character energy from start to finish 👑✨

📦 where this page comes from