apple_smc_write(9)

💖 NAME 💖

okay so bestie, this is apple_smc_write(9) from the Kernel API Manual, and it’s literally here to write size bytes into the given SMC key from buf. no cap, that’s the whole assignment. 🫶

✨ SYNOPSIS ✨

int apple_smc_write (struct apple_smc *smc , smc_key key , const void
       *buf , size_t size );

🌸 ARGUMENTS 🌸

• smc — pointer to an struct apple_smc, aka the SMC struct you’re working with. main character energy fr. 💅
• key — the smc_key that the data will be written to. this is the destination key, periodt.
• buf — buffer from which size bytes of data will be written to SMC. think of it as the little data snack bag you’re emptying into the key. 🍓
• size — number of bytes to be written. count ‘em, bestie. 🔢

🦋 RETURN 🦋

Zero on success — slay ✅. Negative errno on error — so if it comes back negative, something went off and you go check that errno. 😭

👑 SEE ALSO 👑

okay so there’s a whole friend group here, and you should absolutely go peek at them:

• Kernel file ./include/linux/mfd/macsmc.h — yes, the actual file path, bestie.
• smc_key(9)
• SMC_KEY(9)
• struct apple_smc_key_info(9)
• enum apple_smc_boot_stage(9)
• struct apple_smc(9)
• apple_smc_read(9)
• apple_smc_enter_atomic(9)
• apple_smc_write_atomic(9)
• apple_smc_rw(9)
• apple_smc_get_key_by_index(9)
• apple_smc_get_key_info(9)
• apple_smc_key_exists(9)

mwah 💋 this page came from source/version ./include/linux/mfd and is dated October 2026 — iykyk, go write those bytes responsibly. 🌈✨