meson_sm_call_read(9)

🌸 meson_sm_call_read(9) 🌸

okay so bestie, welcome to the glow-up of the Kernel API Manual's page on meson_sm_call_read — yes that's a section 9 function, kernel-internal vibes only, iykyk ✨

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💖 NAME 💖

meson_sm_call_read — literally just retrieve data from secure-monitor. that's it, that's the whole job 💅

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🦋 SYNOPSIS 🦋

int meson_sm_call_read (struct meson_sm_firmware *fw , void *buffer ,
unsigned int bsize , unsigned int cmd_index , u32 arg0 , u32 arg1 , u32
arg2 , u32 arg3 , u32 arg4 );

like, yes, it returns an int and yes it takes a lot of args. we love a main character with a long signature 🎀

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🌈 ARGUMENTS 🌈

okay so here's the whole cast, no skips, no "etc." — every single one:

• fw — pointer to secure-monitor firmware 💫 the actual firmware object you're talking to.
• buffer — buffer to store the retrieved data 📥 your lil drop-off spot for the goods.
• bsize — size of the buffer 📏 how much room buffer has.
• cmd_index — index of the SMC32 function ID 🔢 which secure-monitor function you're calling.
• arg0 — SMC32 Argument 0
• arg1 — SMC32 Argument 1
• arg2 — SMC32 Argument 2
• arg3 — SMC32 Argument 3
• arg4 — SMC32 Argument 4

(yeah the five args are just arg0 through arg4, the SMC32 argument squad, no notes 🫶)

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⭐ RETURN ⭐

on success you get the size of read data, and on error you get a negative value. iconic, straightforward, we stan 🌟

but bestie listen — when 0 is returned there is no guarantee about the amount of data read, and bsize bytes are copied in buffer. so don't go assuming 0 means "nothing happened", because it does not 🙈

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👑 SEE ALSO 👑

• Kernel file ./drivers/firmware/meson/meson_sm.c
• meson_sm_call(9)
• meson_sm_call_write(9)
• meson_sm_get(9)
• meson_sm_get_thermal_calib(9)

go read those too, they're the friend group, they come as a set 🧚💜

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so yeah — that's the tea ☕ this page lives under ./drivers/firmware/meson, and it's dated October 2026 🗓️✨ ty for coming to my ted talk, mwah 💋