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