dell-smbios-wmi 1.5 KB

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  1. What: /dev/wmi/dell-smbios
  2. Date: November 2017
  3. KernelVersion: 4.15
  4. Contact: "Mario Limonciello" <mario.limonciello@dell.com>
  5. Description:
  6. Perform SMBIOS calls on supported Dell machines.
  7. through the Dell ACPI-WMI interface.
  8. IOCTL's and buffer formats are defined in:
  9. <uapi/linux/wmi.h>
  10. 1) To perform an SMBIOS call from userspace, you'll need to
  11. first determine the minimum size of the calling interface
  12. buffer for your machine.
  13. Platforms that contain larger buffers can return larger
  14. objects from the system firmware.
  15. Commonly this size is either 4k or 32k.
  16. To determine the size of the buffer read() a u64 dword from
  17. the WMI character device /dev/wmi/dell-smbios.
  18. 2) After you've determined the minimum size of the calling
  19. interface buffer, you can allocate a structure that represents
  20. the structure documented above.
  21. 3) In the 'length' object store the size of the buffer you
  22. determined above and allocated.
  23. 4) In this buffer object, prepare as necessary for the SMBIOS
  24. call you're interested in. Typically SMBIOS buffers have
  25. "class", "select", and "input" defined to values that coincide
  26. with the data you are interested in.
  27. Documenting class/select/input values is outside of the scope
  28. of this documentation. Check with the libsmbios project for
  29. further documentation on these values.
  30. 6) Run the call by using ioctl() as described in the header.
  31. 7) The output will be returned in the buffer object.
  32. 8) Be sure to free up your allocated object.