chid: Provide a command to access chid features

Provide a simple command which supports showing the information which
goes into calculating a CHID. The information is obtained entirely from
SMBIOS tables at present.

Co-developed-by: Claude <noreply@anthropic.com>
Signed-off-by: Simon Glass <sjg@chromium.org>

doc/usage/cmd/chid.rst

@@ -0,0 +1,67 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+chid command
+============
+
+Synopsis
+--------
+
+::
+
+    chid show
+
+Description
+-----------
+
+The chid command provides access to Computer Hardware IDs (CHIDs) generated from
+SMBIOS data. CHIDs are used by Windows Update and fwupd for hardware
+identification and firmware-update targeting.
+
+CHIDs are generated according to Microsoft's specification, which defines 15
+different hardware ID variants (HardwareID-00 through HardwareID-14), each
+using different combinations of SMBIOS fields. The variants range from most
+specific (including all identifying fields) to least specific (manufacturer
+only).
+
+Subcommands
+-----------
+
+show
+    Show the relevant SMBIOS values for the current board. These are used to
+    calculate CHIDs.
+
+
+Examples
+--------
+
+::
+
+    => chid show
+    Manufacturer:      Sandbox Corp
+    Family:            Sandbox_Family
+    Product Name:      Sandbox Computer
+    Product SKU:       SANDBOX-SKU
+    Baseboard Manuf:   Sandbox Boards
+    Baseboard Product: Sandbox Motherboard
+    BIOS Vendor:       U-Boot
+    BIOS Version:      2025.08-g167811e037b5-dirty
+    BIOS Major:        25
+    BIOS Minor:        8
+    Enclosure Type:    2
+    =>
+
+
+Configuration
+-------------
+
+The chid command is available when `CONFIG_CMD_CHID` is enabled.
+
+Return value
+------------
+
+The return value $? is 0 (true) on success, 1 (false) on failure.
+
+See also
+--------
+
+* :doc:`smbios <smbios>` - SMBIOS table information

doc/usage/index.rst

@@ -49,6 +49,7 @@ Shell commands
    cmd/cbcmos
    cmd/cbsysinfo
    cmd/cedit
+   cmd/chid
    cmd/cli
    cmd/cls
    cmd/cmp