BMC: Store RedundancyPriority on System.

This commit extends the functionality of the BMC software updater by
preserving RedundancyPriority values through any kind of reset.

This is accomplished by storing priority values in serial files in
/var/lib/obmc/phosphor-bmc-code-mgmt/ using the Cereal library. Each
time a priority value is modified, the value in the corresponding
version file is adjusted.

Resolves openbmc/openbmc#2125

Change-Id: Ie697279895bc5ff5fdef31fa88c78dc2bc63390a
Signed-off-by: Saqib Khan <khansa@us.ibm.com>

1 files changed, 34 insertions, 0 deletions

diff --git a/serialize.hpp b/serialize.hpp
new file mode 100644
index 0000000..7b6461f
--- /dev/null
+++ b/serialize.hpp
@@ -0,0 +1,34 @@
+#pragma once
+
+#include <experimental/filesystem>
+#include "config.h"
+
+namespace phosphor
+{
+namespace software
+{
+namespace updater
+{
+
+namespace fs = std::experimental::filesystem;
+
+/** @brief Serialization function - stores activation information to file
+ *  @param[in] versionId - The version for which to store information.
+ *  @param[in] priority - RedundancyPriority value for that version.
+ **/
+void storeToFile(std::string versionId, uint8_t priority);
+
+/** @brief Serialization function - restores activation information from file
+ *  @param[in] versionId - The version for which to retrieve information.
+ *  @param[in] priority - RedundancyPriority reference for that version.
+ **/
+void restoreFromFile(std::string versionId, uint8_t& priority);
+
+/** @brief Removes the serial file for a given version.
+ *  @param[in] versionId - The version for which to remove a file, if it exists.
+ **/
+void removeFile(std::string versionId);
+
+} // namespace phosphor
+} // namespace software
+} // namespace openpower