0001 What: /dev/wmi/dell-smbios
0002 Date: November 2017
0003 KernelVersion: 4.15
0004 Contact: Dell.Client.Kernel@dell.com
0005 Description:
0006 Perform SMBIOS calls on supported Dell machines.
0007 through the Dell ACPI-WMI interface.
0008
0009 IOCTL's and buffer formats are defined in:
0010 <uapi/linux/wmi.h>
0011
0012 1) To perform an SMBIOS call from userspace, you'll need to
0013 first determine the minimum size of the calling interface
0014 buffer for your machine.
0015 Platforms that contain larger buffers can return larger
0016 objects from the system firmware.
0017 Commonly this size is either 4k or 32k.
0018
0019 To determine the size of the buffer read() a u64 dword from
0020 the WMI character device /dev/wmi/dell-smbios.
0021
0022 2) After you've determined the minimum size of the calling
0023 interface buffer, you can allocate a structure that represents
0024 the structure documented above.
0025
0026 3) In the 'length' object store the size of the buffer you
0027 determined above and allocated.
0028
0029 4) In this buffer object, prepare as necessary for the SMBIOS
0030 call you're interested in. Typically SMBIOS buffers have
0031 "class", "select", and "input" defined to values that coincide
0032 with the data you are interested in.
0033 Documenting class/select/input values is outside of the scope
0034 of this documentation. Check with the libsmbios project for
0035 further documentation on these values.
0036
0037 6) Run the call by using ioctl() as described in the header.
0038
0039 7) The output will be returned in the buffer object.
0040
0041 8) Be sure to free up your allocated object.
