DEVICE_GET_SYSCTL(9)

💖 DEVICE_GET_SYSCTL — the device_get_sysctl_ctx / device_get_sysctl_tree situation 💖

okay bestie, so this is a page from the Kernel Developer's Manual (that's the (9) part, iykyk) and it's literally all about poking at the sysctl oid tree for driver-specific sysctl nodes. short page, big energy. let's get into it 🦋

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✨ NAME ✨

device_get_sysctl_ctx, device_get_sysctl_tree — manipulate the sysctl oid tree for driver specific sysctl nodes

like... that's the whole job description. two lil functions, one tree, zero drama. 💅

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🌸 SYNOPSIS 🌸

first, the receipts you gotta include:

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

then, the icons themselves:

struct sysctl_ctx_list *
device_get_sysctl_ctx(device_t dev);

struct sysctl_oid *
device_get_sysctl_tree(device_t dev);

see how they both take a device_t dev? yeah. they're besties. same input, different vibes. 🫶

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💫 DESCRIPTION 💫

okay so here's the tea: the newbus system is out here being the main character and it automatically adds a sysctl node for every single device in the system. no cap. every one. it just does it. iconic behaviour honestly. 👑

so if you want to get your hands on that node, that's what device_get_sysctl_tree() is for — it hands you the node, that's it, that's the function. 🎀

and if you want the context for that node instead? that's device_get_sysctl_ctx()'s whole thing. it gives you the context. boom. done. ✨

so like:

• want the node? device_get_sysctl_tree() 🦋
• want the context for the node? device_get_sysctl_ctx() 🌸

that's literally the entire dynamic. two functions, one automatic node per device, everybody slays. 💜

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👀 SEE ALSO 👀

• device(9)

go read that one too bestie, it's giving related-content energy. 🍓

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💅 AUTHORS 💅

This manual page was written by Warner Losh. yes, actual real human, actual real page, we stan. 🙈

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and that's a wrap!! this whole thing came from the Debian crew and it's dated June 18, 2011 — shoutout to 2011 for being the moment this page was born, fr fr. 💖✨🎀