doc/opal-api: Documentation for opal-nvram-read-write

This patch adds documentation for OPAL_READ_NVRAM and OPAL_WRITE_NVRAM

Signed-off-by: Pridhiviraj Paidipeddi <ppaidipe@linux.vnet.ibm.com>
Reviewed-by: Mukesh Ojha <mukesh02@linux.vnet.ibm.com>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

1 files changed, 76 insertions, 0 deletions

diff --git a/doc/opal-api/opal-nvram-read-write-7-8.rst b/doc/opal-api/opal-nvram-read-write-7-8.rst
new file mode 100644
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+OPAL_READ_NVRAM
+===============
+::
+
+   #define OPAL_READ_NVRAM                         7
+
+``OPAL_READ_NVRAM`` call requests OPAL to read the data from system NVRAM
+memory into a memory buffer. The data at ``offset`` from nvram_image
+will be copied to memory ``buffer`` of size ``size``.
+
+Parameters
+----------
+::
+
+   uint64_t buffer
+   uint64_t size
+   uint64_t offset
+
+``buffer``
+   the data from nvram will be copied to ``buffer``
+
+``size``
+   the data of size ``size`` will be copied
+
+``offset``
+   the data will be copied from address equal to base ``nvram_image`` plus ``offset``
+
+Return Values
+-------------
+
+``OPAL_SUCCESS``
+  data from nvram to memory ``buffer`` copied successfully
+
+``OPAL_PARAMETER``
+  a parameter ``offset`` or ``size`` was incorrect
+
+``OPAL_HARDWARE``
+  either nvram is not initialized or permanent error related to nvram hardware.
+
+OPAL_WRITE_NVRAM
+================
+::
+
+   #define OPAL_WRITE_NVRAM                        8
+
+``OPAL_WRITE_NVRAM`` call requests OPAL to write the data to actual system NVRAM memory
+ from memory ``buffer`` at ``offset``, of size ``size``
+
+Parameters
+----------
+::
+
+   uint64_t buffer
+   uint64_t size
+   uint64_t offset
+
+``buffer``
+   data from ``buffer`` will be copied to nvram
+
+``size``
+   the data of size ``size`` will be copied
+
+``offset``
+   the data will be copied to address which is equal to base ``nvram_image`` plus ``offset``
+
+Return Values
+-------------
+
+``OPAL_SUCCESS``
+  data from memory ``buffer`` to actual nvram_image copied successfully
+
+``OPAL_PARAMETER``
+  a parameter ``offset`` or ``size`` was incorrect
+
+``OPAL_HARDWARE``
+  either nvram is not initialized or permanent error related to nvram hardware.