s10_protected_reg_read(9)

✨ s10_protected_reg_read — the Kernel API Manual (section 9, bestie) ✨

okay so real talk, we're in the Kernel API Manual, section 9, and today's main character is s10_protected_reg_read. she reads a register. she's protected. she's booked and busy. 💅

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🌸 NAME 🌸

s10_protected_reg_read — literally it's just the function name up here, no extra blurb, the name is the serve 🎀

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🦋 SYNOPSIS 🦋

int s10_protected_reg_read (void *base , unsigned int reg , unsigned int
*val );

three args, one int coming back at you, that's the whole vibe 🫶

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💖 ARGUMENTS 💖

• base — the base address of the System Manager. like, where the System Manager lives. that's her address 🏠
• reg — the address of the register. yes, address of the register, not the value, don't get it twisted 🙈
• val — the value that got read. she gets filled in for you, icon behaviour ✨

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🔥 DESCRIPTION 🔥

so what does she actually do? she reads the status of a protected SMC register. that's it. that's the whole plot. no cap, she's not doing side quests 💀

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👑 RETURN 👑

she comes back with one of these, and which one you get tells you everything:

• INTEL_SIP_SMC_STATUS_OK (0) — slay, it worked, success, we love to see it 💚
• INTEL_SIP_SMC_REG_ERROR — uh oh, error, something went sideways 😭
• INTEL_SIP_SMC_RETURN_UNKNOWN_FUNCTION — the function just isn't supported, so sorry bestie, not today 🙈

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🌈 SEE ALSO 🌈

go touch grass in these, they're all connected iykyk:

• the kernel file ./drivers/mfd/altera-sysmgr.c
• struct altr_sysmgr(9)
• s10_protected_reg_write(9) — yeah she has a sister, the write one, go say hi 🫶
• altr_sysmgr_regmap_lookup_by_phandle(9)

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okay that's the whole page, you understood it, I'm so proud of you fr fr 🧚💜

mwah 💋 — this cutie came out of ./drivers/mfd in October 2026, that's the source/version and the date, all wrapped up in a little sign-off because you deserve it ⭐