SBRMI_IOCTL_MCAMSR_CMD(9)

💅 SBRMI_IOCTL_MCAMSR_CMD 💅

okay bestie so this is a page from the Kernel API Manual — the SBRMI_IOCTL_MCAMSR_CMD(9) one, yes the whole title is a vibe, don't worry about it ✨

🌸 Parameters 🌸

• struct apml_mcamsr_msg — this is a pointer, and it points at the struct apml_mcamsr_msg that's gonna be holding all the protocol info. that's literally its whole job 🫶

✨ Description ✨

so this one's an IOCTL command for APML messages, and it uses the generic _IOWR. slay. what it does is give userspace access to the AMD sideband MCAMSR protocol — main character energy fr fr 👑

here's the breakdown:

• the MCAMSR protocol gets you the MCA bank details for a Function at thread level 🧚
• and it returns "-EFAULT" if none of the above happens — and then a "-EPROTOTYPE" error gets returned too, so you get those extra error deets. iykyk 😭

🦋 SEE ALSO 🦋

go look at the kernel file ./include/uapi/misc/amd-apml.h — and also these icons:

• SBRMI_IOCTL_MBOX_CMD(9)
• SBRMI_IOCTL_CPUID_CMD(9)
• SBRMI_IOCTL_REG_XFER_CMD(9)
• SBTSI_IOCTL_REG_XFER_CMD(9)

okay that's the whole page, no cap 💖 this one lives in ./include/uapi/misc, dated October 2026 — so yeah, from the future bestie, periodt 🌈⭐🎀