1What: /dev/wmi/dell-smbios 2Date: November 2017 3KernelVersion: 4.15 4Contact: Dell.Client.Kernel@dell.com 5Description: 6 Perform SMBIOS calls on supported Dell machines. 7 through the Dell ACPI-WMI interface. 8 9 IOCTL's and buffer formats are defined in: 10 <uapi/linux/wmi.h> 11 12 1) To perform an SMBIOS call from userspace, you'll need to 13 first determine the minimum size of the calling interface 14 buffer for your machine. 15 Platforms that contain larger buffers can return larger 16 objects from the system firmware. 17 Commonly this size is either 4k or 32k. 18 19 To determine the size of the buffer read() a u64 dword from 20 the WMI character device /dev/wmi/dell-smbios. 21 22 2) After you've determined the minimum size of the calling 23 interface buffer, you can allocate a structure that represents 24 the structure documented above. 25 26 3) In the 'length' object store the size of the buffer you 27 determined above and allocated. 28 29 4) In this buffer object, prepare as necessary for the SMBIOS 30 call you're interested in. Typically SMBIOS buffers have 31 "class", "select", and "input" defined to values that coincide 32 with the data you are interested in. 33 Documenting class/select/input values is outside of the scope 34 of this documentation. Check with the libsmbios project for 35 further documentation on these values. 36 37 6) Run the call by using ioctl() as described in the header. 38 39 7) The output will be returned in the buffer object. 40 41 8) Be sure to free up your allocated object. 42