DEVICE_GET_IVARS(9)

💖 DEVICE_GET_IVARS(9) 💖

okay bestie, welcome to the device_get_ivars / device_set_ivars page from the Kernel Developer's Manual ✨ this one's short and sweet but it's lowkey important, so let's get into it 🫶

🌸 NAME 🌸

device_get_ivars, device_set_ivars — access bus private variables 💅

✨ SYNOPSIS ✨

#include <sys/param.h>
#include <sys/bus.h>

void *
device_get_ivars(device_t dev);

void
device_set_ivars(device_t dev, void *ivar);

🦋 DESCRIPTION 🦋

so the way this works: device_get_ivars() hands you back the bus-specific instance variables of a device. it's giving "here's your stuff, bestie" 🎀

and then device_set_ivars() is the reverse — it sets the bus-specific instance variables of a device. iconic duo fr fr 👑

ngl, typically only bus drivers use these functions. the kernel is literally assuming that the bus driver is gonna manage this memory — there is no automatic memory allocation or deallocation happening here. none. zero. not a crumb. 😭

so if you're a client driver, please don't come through here — you should be accessing ivars through the BUS_READ_IVAR(9) interface instead. that's the vibe check, and you passed it 💖

🌈 SEE ALSO 🌈

• device(9)

🎀 AUTHORS 🎀

this manual page was written by Doug Rabson. thank you Doug, we are obsessed 🫶✨

and that's a wrap, bestie 🦋 this page came to you from Debian, dated June 16, 1998 — vintage fr, main character energy from the very start 👑💅 slay, mwah 🍓