doc: describe generation of SMBIOS table

SMBIOS is not x86 specific. So we should have an architecture independent
page describing it.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/doc/arch/x86.rst b/doc/arch/x86.rst
index 5494155..634387a 100644
--- a/doc/arch/x86.rst
+++ b/doc/arch/x86.rst
@@ -732,7 +732,7 @@
 To generate SMBIOS tables in U-Boot, for use by the OS, enable the
 CONFIG_GENERATE_SMBIOS_TABLE option. The easiest way to provide the values to
 use is via the device tree. For details see
-device-tree-bindings/sysinfo/smbios.txt
+:download:`smbios.txt <../device-tree-bindings/sysinfo/smbios.txt>`.
 
 TODO List
 ---------
diff --git a/doc/develop/index.rst b/doc/develop/index.rst
index 9714887..93ebfa4 100644
--- a/doc/develop/index.rst
+++ b/doc/develop/index.rst
@@ -22,6 +22,7 @@
    makefiles
    menus
    printf
+   smbios
    uefi/index
    version
 
diff --git a/doc/develop/smbios.rst b/doc/develop/smbios.rst
new file mode 100644
index 0000000..a4efb0a
--- /dev/null
+++ b/doc/develop/smbios.rst
@@ -0,0 +1,22 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+SMBIOS tables
+=============
+
+The System Management BIOS (SMBIOS) table is used to deliver management
+information from the firmware to the operating system. The content is
+standardized in [1]_.
+
+In Linux you can use the dmidecode command to view the contents of the SMBIOS
+table.
+
+When booting via UEFI the SMBIOS table is transferred as an UEFI configuration
+table to the operating system.
+
+To generate SMBIOS tables in U-Boot, the CONFIG_GENERATE_SMBIOS_TABLE option
+must be enabled. The easiest way to provide the values to use is via the device
+tree. For details see
+:download:`smbios.txt <../device-tree-bindings/sysinfo/smbios.txt>`.
+
+.. [1] `System Management BIOS (SMBIOS) Reference, version 3.5
+   <https://www.dmtf.org/content/dmtf-releases-smbios-35>`_