item_updater.cpp - openbmc/openpower-pnor-code-mgmt - Gitiles

 #include <string>
 #include <experimental/filesystem>
 #include <fstream>
 #include <phosphor-logging/elog-errors.hpp>
 #include <phosphor-logging/log.hpp>
 #include "xyz/openbmc_project/Common/error.hpp"
 #include <xyz/openbmc_project/Software/Version/server.hpp>
 #include "version.hpp"
 #include "config.h"
 #include "item_updater.hpp"
 #include "activation.hpp"
 #include "serialize.hpp"

 namespace openpower
 {
 namespace software
 {
 namespace updater
 {

 // When you see server:: you know we're referencing our base class
 namespace server = sdbusplus::xyz::openbmc_project::Software::server;
 namespace fs = std::experimental::filesystem;

 using namespace sdbusplus::xyz::openbmc_project::Common::Error;
 using namespace phosphor::logging;

 constexpr auto squashFSImage = "pnor.xz.squashfs";
 constexpr auto CHASSIS_STATE_PATH = "/xyz/openbmc_project/state/chassis0";
 constexpr auto CHASSIS_STATE_OBJ = "xyz.openbmc_project.State.Chassis";
 constexpr auto CHASSIS_STATE_OFF =
                         "xyz.openbmc_project.State.Chassis.PowerState.Off";
 constexpr auto SYSTEMD_PROPERTY_INTERFACE = "org.freedesktop.DBus.Properties";

 // TODO: Change paths once openbmc/openbmc#1663 is completed.
 constexpr auto MBOXD_INTERFACE = "org.openbmc.mboxd";
 constexpr auto MBOXD_PATH = "/org/openbmc/mboxd";

 void ItemUpdater::createActivation(sdbusplus::message::message& m)
 {
     using SVersion = server::Version;
     using VersionPurpose = SVersion::VersionPurpose;
     namespace msg = sdbusplus::message;
     namespace variant_ns = msg::variant_ns;

     sdbusplus::message::object_path objPath;
     std::map<std::string,
              std::map<std::string, msg::variant<std::string>>> interfaces;
     m.read(objPath, interfaces);

     std::string path(std::move(objPath));
     std::string filePath;
     auto purpose = VersionPurpose::Unknown;
     std::string version;

     for (const auto& intf : interfaces)
     {
         if (intf.first == VERSION_IFACE)
         {
             for (const auto& property : intf.second)
             {
                 if (property.first == "Purpose")
                 {
                     // Only process the Host and System images
                     auto value = SVersion::convertVersionPurposeFromString(
                             variant_ns::get<std::string>(property.second));

                     if (value == VersionPurpose::Host ||
                         value == VersionPurpose::System)
                     {
                         purpose = value;
                     }
                 }
                 else if (property.first == "Version")
                 {
                     version = variant_ns::get<std::string>(property.second);
                 }
             }
         }
         else if (intf.first == FILEPATH_IFACE)
         {
             for (const auto& property : intf.second)
             {
                 if (property.first == "Path")
                 {
                     filePath = variant_ns::get<std::string>(property.second);
                 }
             }
         }
     }
     if ((filePath.empty()) || (purpose == VersionPurpose::Unknown))
     {
         return;
     }

     // Version id is the last item in the path
     auto pos = path.rfind("/");
     if (pos == std::string::npos)
     {
         log<level::ERR>("No version id found in object path",
                         entry("OBJPATH=%s", path));
         return;
     }

     auto versionId = path.substr(pos + 1);

     if (activations.find(versionId) == activations.end())
     {
         // Determine the Activation state by processing the given image dir.
         auto activationState = server::Activation::Activations::Invalid;
         AssociationList associations = {};
         if (ItemUpdater::validateSquashFSImage(filePath) == 0)
         {
             activationState = server::Activation::Activations::Ready;
             // Create an association to the host inventory item
             associations.emplace_back(std::make_tuple(
                                               ACTIVATION_FWD_ASSOCIATION,
                                               ACTIVATION_REV_ASSOCIATION,
                                               HOST_INVENTORY_PATH));
         }

         fs::path manifestPath(filePath);
         manifestPath /= MANIFEST_FILE;
         std::string extendedVersion = (Version::getValue(manifestPath.string(),
                  std::map<std::string, std::string>
                  {{"extended_version", ""}})).begin()->second;

         activations.insert(std::make_pair(
                 versionId,
                 std::make_unique<Activation>(
                         bus,
                         path,
                         *this,
                         versionId,
                         extendedVersion,
                         activationState,
                         associations)));
         versions.insert(std::make_pair(
                             versionId,
                             std::make_unique<Version>(
                                 bus,
                                 path,
                                 version,
                                 purpose,
                                 filePath)));
     }
     return;
 }

 void ItemUpdater::processPNORImage()
 {
     // Read pnor.toc from folders under /media/
     // to get Active Software Versions.
     for (const auto& iter : fs::directory_iterator(MEDIA_DIR))
     {
         auto activationState = server::Activation::Activations::Active;

         static const auto PNOR_RO_PREFIX_LEN = strlen(PNOR_RO_PREFIX);
         static const auto PNOR_RW_PREFIX_LEN = strlen(PNOR_RW_PREFIX);

         // Check if the PNOR_RO_PREFIX is the prefix of the iter.path
         if (0 == iter.path().native().compare(0, PNOR_RO_PREFIX_LEN,
                                               PNOR_RO_PREFIX))
         {
             // The versionId is extracted from the path
             // for example /media/pnor-ro-2a1022fe.
             auto id = iter.path().native().substr(PNOR_RO_PREFIX_LEN);
             auto pnorTOC = iter.path() / PNOR_TOC_FILE;
             if (!fs::is_regular_file(pnorTOC))
             {
                 log<level::ERR>("Failed to read pnorTOC.",
                                 entry("FILENAME=%s", pnorTOC.string()));
                 ItemUpdater::erase(id);
                 continue;
             }
             auto keyValues =
                     Version::getValue(pnorTOC,
                                       {{ "version", "" },
                                        { "extended_version", "" } });
             auto& version = keyValues.at("version");
             if (version.empty())
             {
                 log<level::ERR>("Failed to read version from pnorTOC",
                                 entry("FILENAME=%s", pnorTOC.string()));
                 activationState = server::Activation::Activations::Invalid;
             }

             auto& extendedVersion = keyValues.at("extended_version");
             if (extendedVersion.empty())
             {
                 log<level::ERR>("Failed to read extendedVersion from pnorTOC",
                                 entry("FILENAME=%s", pnorTOC.string()));
                 activationState = server::Activation::Activations::Invalid;
             }

             auto purpose = server::Version::VersionPurpose::Host;
             auto path = fs::path(SOFTWARE_OBJPATH) / id;
             AssociationList associations = {};

             if (activationState == server::Activation::Activations::Active)
             {
                 // Create an association to the host inventory item
                 associations.emplace_back(std::make_tuple(
                                                   ACTIVATION_FWD_ASSOCIATION,
                                                   ACTIVATION_REV_ASSOCIATION,
                                                   HOST_INVENTORY_PATH));

                 // Create an active association since this image is active
                 createActiveAssociation(path);
             }

             // Create Activation instance for this version.
             activations.insert(std::make_pair(
                                    id,
                                    std::make_unique<Activation>(
                                        bus,
                                        path,
                                        *this,
                                        id,
                                        extendedVersion,
                                        activationState,
                                        associations)));

             // If Active, create RedundancyPriority instance for this version.
             if (activationState == server::Activation::Activations::Active)
             {
                 uint8_t priority = std::numeric_limits<uint8_t>::max();
                 if (!restoreFromFile(id, priority))
                 {
                     log<level::ERR>("Unable to restore priority from file.",
                                     entry("VERSIONID=%s", id));
                 }
                 activations.find(id)->second->redundancyPriority =
                          std::make_unique<RedundancyPriority>(
                              bus,
                              path,
                              *(activations.find(id)->second),
                              priority);
             }

             // Create Version instance for this version.
             versions.insert(std::make_pair(
                                 id,
                                 std::make_unique<Version>(
                                      bus,
                                      path,
                                      version,
                                      purpose,
                                      "")));
         }
         else if (0 == iter.path().native().compare(0, PNOR_RW_PREFIX_LEN,
                                                       PNOR_RW_PREFIX))
         {
             auto id = iter.path().native().substr(PNOR_RW_PREFIX_LEN);
             auto roDir = PNOR_RO_PREFIX + id;
             if (!fs::is_directory(roDir))
             {
                 log<level::ERR>("No corresponding read-only volume found.",
                                 entry("DIRNAME=%s", roDir));
                 ItemUpdater::erase(id);
             }
         }
     }

     // Look at the RO symlink to determine if there is a functional image
     auto id = determineId(PNOR_RO_ACTIVE_PATH);
     if (!id.empty())
     {
         updateFunctionalAssociation(std::string{SOFTWARE_OBJPATH} + '/' + id);
     }
     return;
 }

 int ItemUpdater::validateSquashFSImage(const std::string& filePath)
 {
     auto file = fs::path(filePath) / squashFSImage;
     if (fs::is_regular_file(file))
     {
         return 0;
     }
     else
     {
         log<level::ERR>("Failed to find the SquashFS image.");
         return -1;
     }
 }

 void ItemUpdater::removeReadOnlyPartition(std::string versionId)
 {
         auto serviceFile = "obmc-flash-bios-ubiumount-ro@" + versionId +
                 ".service";

         // Remove the read-only partitions.
         auto method = bus.new_method_call(
                 SYSTEMD_BUSNAME,
                 SYSTEMD_PATH,
                 SYSTEMD_INTERFACE,
                 "StartUnit");
         method.append(serviceFile, "replace");
         bus.call_noreply(method);
 }

 void ItemUpdater::removeReadWritePartition(std::string versionId)
 {
         auto serviceFile = "obmc-flash-bios-ubiumount-rw@" + versionId +
                 ".service";

         // Remove the read-write partitions.
         auto method = bus.new_method_call(
                 SYSTEMD_BUSNAME,
                 SYSTEMD_PATH,
                 SYSTEMD_INTERFACE,
                 "StartUnit");
         method.append(serviceFile, "replace");
         bus.call_noreply(method);
 }

 void ItemUpdater::reset()
 {
     for (const auto& it : activations)
     {
         auto serviceFile = "obmc-flash-bios-ubiclear@pnor-rw-" + it.first +
                 ".service";

         // Clear the read-write partitions.
         auto method = bus.new_method_call(
                 SYSTEMD_BUSNAME,
                 SYSTEMD_PATH,
                 SYSTEMD_INTERFACE,
                 "StartUnit");
         method.append(serviceFile, "replace");
         auto reply = bus.call(method);

         if (reply.is_method_error())
         {
             log<level::ERR>("Failed to clear read-write partitions",
                     entry("SERVICE_FILE=%s", serviceFile));
             elog<InternalFailure>();
         }

         removeFile(it.first);
     }
     static constexpr auto serviceFile =
             "obmc-flash-bios-ubiclear@pnor-prsv.service";
     // Clear the preserved partition.
     auto method = bus.new_method_call(
             SYSTEMD_BUSNAME,
             SYSTEMD_PATH,
             SYSTEMD_INTERFACE,
             "StartUnit");
     method.append(serviceFile, "replace");
     auto reply = bus.call(method);

     if (reply.is_method_error())
     {
         log<level::ERR>("Failed to clear preserved partition",
                     entry("SERVICE_FILE=%s", serviceFile));
         elog<InternalFailure>();
     }

     return;
 }

 bool ItemUpdater::isVersionFunctional(std::string versionId)
 {
     if (!fs::exists(PNOR_RO_ACTIVE_PATH))
     {
         return false;
     }

     fs::path activeRO = fs::read_symlink(PNOR_RO_ACTIVE_PATH);

     if (!fs::is_directory(activeRO))
     {
         return false;
     }

     if (activeRO.string().find(versionId) == std::string::npos)
     {
         return false;
     }

     // active PNOR is the version we're checking
     return true;
 }

 bool ItemUpdater::isChassisOn()
 {
     auto mapperCall = bus.new_method_call(
             MAPPER_BUSNAME,
             MAPPER_PATH,
             MAPPER_INTERFACE,
             "GetObject");

     mapperCall.append(CHASSIS_STATE_PATH,
                       std::vector<std::string>({CHASSIS_STATE_OBJ}));
     auto mapperResponseMsg = bus.call(mapperCall);
     if (mapperResponseMsg.is_method_error())
     {
         log<level::ERR>("Error in Mapper call");
         elog<InternalFailure>();
     }
     using MapperResponseType = std::map<std::string, std::vector<std::string>>;
     MapperResponseType mapperResponse;
     mapperResponseMsg.read(mapperResponse);
     if (mapperResponse.empty())
     {
         log<level::ERR>("Invalid Response from mapper");
         elog<InternalFailure>();
     }

     auto method = bus.new_method_call((mapperResponse.begin()->first).c_str(),
                                       CHASSIS_STATE_PATH,
                                       SYSTEMD_PROPERTY_INTERFACE,
                                       "Get");
     method.append(CHASSIS_STATE_OBJ, "CurrentPowerState");
     auto response = bus.call(method);
     if (response.is_method_error())
     {
         log<level::ERR>("Error in fetching current Chassis State",
                         entry("MAPPERRESPONSE=%s",
                               (mapperResponse.begin()->first).c_str()));
         elog<InternalFailure>();
     }
     sdbusplus::message::variant<std::string> currentChassisState;
     response.read(currentChassisState);
     auto strParam =
         sdbusplus::message::variant_ns::get<std::string>(currentChassisState);
     return (strParam != CHASSIS_STATE_OFF);
 }

 void ItemUpdater::freePriority(uint8_t value, const std::string& versionId)
 {
     //TODO openbmc/openbmc#1896 Improve the performance of this function
     for (const auto& intf : activations)
     {
         if (intf.second->redundancyPriority)
         {
             if (intf.second->redundancyPriority.get()->priority() == value &&
                 intf.second->versionId != versionId)
             {
                 intf.second->redundancyPriority.get()->priority(value + 1);
             }
         }
     }
 }

 bool ItemUpdater::isLowestPriority(uint8_t value)
 {
     for (const auto& intf : activations)
     {
         if (intf.second->redundancyPriority)
         {
             if (intf.second->redundancyPriority.get()->priority() < value)
             {
                 return false;
             }
         }
     }
     return true;
 }

 void ItemUpdater::erase(std::string entryId)
 {
     if (isVersionFunctional(entryId) && isChassisOn()) {
         log<level::ERR>(("Error: Version " + entryId + \
                          " is currently active and running on the host." \
                          " Unable to remove.").c_str());
         return;
     }
     // Remove priority persistence file
     removeFile(entryId);

     // Removing read-only and read-write partitions
     removeReadWritePartition(entryId);
     removeReadOnlyPartition(entryId);

     // Removing entry in versions map
     auto it = versions.find(entryId);
     if (it == versions.end())
     {
         log<level::ERR>(("Error: Failed to find version " + entryId + \
                          " in item updater versions map." \
                          " Unable to remove.").c_str());
         return;
     }
     versions.erase(entryId);

     // Removing entry in activations map
     auto ita = activations.find(entryId);
     if (ita == activations.end())
     {
         log<level::ERR>(("Error: Failed to find version " + entryId + \
                          " in item updater activations map." \
                          " Unable to remove.").c_str());
         return;
     }
     activations.erase(entryId);
 }

 void ItemUpdater::deleteAll()
 {
     std::vector<std::string> deletableActivations;

     for (const auto& activationIt : activations)
     {
         if (!isVersionFunctional(activationIt.first))
         {
             deletableActivations.push_back(activationIt.first);
         }
     }

     for (const auto& deletableIt : deletableActivations)
     {
         ItemUpdater::erase(deletableIt);
     }

     // Remove any remaining pnor-ro- or pnor-rw- volumes that do not match
     // the current version.
     auto method = bus.new_method_call(
             SYSTEMD_BUSNAME,
             SYSTEMD_PATH,
             SYSTEMD_INTERFACE,
             "StartUnit");
     method.append("obmc-flash-bios-cleanup.service", "replace");
     bus.call_noreply(method);
 }

 // TODO: openbmc/openbmc#1402 Monitor flash usage
 void ItemUpdater::freeSpace()
 {
     std::size_t count = 0;
     decltype(activations.begin()->second->redundancyPriority.get()->priority())
             highestPriority = 0;
     decltype(activations.begin()->second->versionId) highestPriorityVersion;
     for (const auto& iter : activations)
     {
         if (iter.second.get()->activation() == server::Activation::Activations::Active)
         {
             count++;
             if (isVersionFunctional(iter.second->versionId))
             {
                 continue;
             }
             if (iter.second->redundancyPriority.get()->priority() >= highestPriority)
             {
                 highestPriority = iter.second->redundancyPriority.get()->priority();
                 highestPriorityVersion = iter.second->versionId;
             }
         }
     }
     // Remove the pnor version with highest priority since the PNOR
     // can't hold more than 2 versions.
     if (count >= ACTIVE_PNOR_MAX_ALLOWED)
     {
         erase(highestPriorityVersion);
     }
 }

 void ItemUpdater::createActiveAssociation(const std::string& path)
 {
     assocs.emplace_back(std::make_tuple(ACTIVE_FWD_ASSOCIATION,
                                         ACTIVE_REV_ASSOCIATION,
                                         path));
     associations(assocs);
 }

 void ItemUpdater::updateFunctionalAssociation(const std::string& path)
 {
     // remove all functional associations
     for (auto iter = assocs.begin(); iter != assocs.end();)
     {
         if ((std::get<0>(*iter)).compare(FUNCTIONAL_FWD_ASSOCIATION) == 0)
         {
             iter = assocs.erase(iter);
         }
         else
         {
             ++iter;
         }
     }
     assocs.emplace_back(std::make_tuple(FUNCTIONAL_FWD_ASSOCIATION,
                                         FUNCTIONAL_REV_ASSOCIATION,
                                         path));
     associations(assocs);
 }

 void ItemUpdater::removeActiveAssociation(const std::string& path)
 {
     for (auto iter = assocs.begin(); iter != assocs.end();)
     {
         if ((std::get<0>(*iter)).compare(ACTIVE_FWD_ASSOCIATION) == 0 &&
             (std::get<2>(*iter)).compare(path) == 0)
         {
             iter = assocs.erase(iter);
             associations(assocs);
         }
         else
         {
             ++iter;
         }
     }
 }

 std::string ItemUpdater::determineId(const std::string& symlinkPath)
 {
     if (!fs::exists(symlinkPath))
     {
         return {};
     }

     auto target = fs::canonical(symlinkPath).string();

     // check to make sure the target really exists
     if (!fs::is_regular_file(target + "/" + PNOR_TOC_FILE))
     {
         return {};
     }
     // Get the image <id> from the symlink target
     // for example /media/ro-2a1022fe
     static const auto PNOR_RO_PREFIX_LEN = strlen(PNOR_RO_PREFIX);
     return target.substr(PNOR_RO_PREFIX_LEN);
 }

 void GardReset::reset()
 {
     // The GARD partition is currently misspelled "GUARD." This file path will
     // need to be updated in the future.
     auto path = fs::path(PNOR_PRSV_ACTIVE_PATH);
     path /= "GUARD";
     std::vector<uint8_t> mboxdArgs;

     auto dbusCall = bus.new_method_call(
             MBOXD_INTERFACE,
             MBOXD_PATH,
             MBOXD_INTERFACE,
             "cmd");

     // Suspend mboxd - no args required.
     dbusCall.append(static_cast<uint8_t>(3), mboxdArgs);

     auto responseMsg = bus.call(dbusCall);
     if (responseMsg.is_method_error())
     {
         log<level::ERR>("Error in mboxd suspend call");
         elog<InternalFailure>();
     }

     if (fs::is_regular_file(path))
     {
         fs::remove(path);
     }

     dbusCall = bus.new_method_call(
             MBOXD_INTERFACE,
             MBOXD_PATH,
             MBOXD_INTERFACE,
             "cmd");

     // Resume mboxd with arg 1, indicating that the flash is modified.
     mboxdArgs.push_back(1);
     dbusCall.append(static_cast<uint8_t>(4), mboxdArgs);

     responseMsg = bus.call(dbusCall);
     if (responseMsg.is_method_error())
     {
         log<level::ERR>("Error in mboxd resume call");
         elog<InternalFailure>();
     }
 }

 } // namespace updater
 } // namespace software
 } // namespace openpower
	#include <string>
	#include <experimental/filesystem>
	#include <fstream>
	#include <phosphor-logging/elog-errors.hpp>
	#include <phosphor-logging/log.hpp>
	#include "xyz/openbmc_project/Common/error.hpp"
	#include <xyz/openbmc_project/Software/Version/server.hpp>
	#include "version.hpp"
	#include "config.h"
	#include "item_updater.hpp"
	#include "activation.hpp"
	#include "serialize.hpp"

	namespace openpower
	{
	namespace software
	{
	namespace updater
	{

	// When you see server:: you know we're referencing our base class
	namespace server = sdbusplus::xyz::openbmc_project::Software::server;
	namespace fs = std::experimental::filesystem;

	using namespace sdbusplus::xyz::openbmc_project::Common::Error;
	using namespace phosphor::logging;

	constexpr auto squashFSImage = "pnor.xz.squashfs";
	constexpr auto CHASSIS_STATE_PATH = "/xyz/openbmc_project/state/chassis0";
	constexpr auto CHASSIS_STATE_OBJ = "xyz.openbmc_project.State.Chassis";
	constexpr auto CHASSIS_STATE_OFF =
	"xyz.openbmc_project.State.Chassis.PowerState.Off";
	constexpr auto SYSTEMD_PROPERTY_INTERFACE = "org.freedesktop.DBus.Properties";

	// TODO: Change paths once openbmc/openbmc#1663 is completed.
	constexpr auto MBOXD_INTERFACE = "org.openbmc.mboxd";
	constexpr auto MBOXD_PATH = "/org/openbmc/mboxd";

	void ItemUpdater::createActivation(sdbusplus::message::message& m)
	{
	using SVersion = server::Version;
	using VersionPurpose = SVersion::VersionPurpose;
	namespace msg = sdbusplus::message;
	namespace variant_ns = msg::variant_ns;

	sdbusplus::message::object_path objPath;
	std::map<std::string,
	std::map<std::string, msg::variant<std::string>>> interfaces;
	m.read(objPath, interfaces);

	std::string path(std::move(objPath));
	std::string filePath;
	auto purpose = VersionPurpose::Unknown;
	std::string version;

	for (const auto& intf : interfaces)
	{
	if (intf.first == VERSION_IFACE)
	{
	for (const auto& property : intf.second)
	{
	if (property.first == "Purpose")
	{
	// Only process the Host and System images
	auto value = SVersion::convertVersionPurposeFromString(
	variant_ns::get<std::string>(property.second));

	if (value == VersionPurpose::Host \|\|
	value == VersionPurpose::System)
	{
	purpose = value;
	}
	}
	else if (property.first == "Version")
	{
	version = variant_ns::get<std::string>(property.second);
	}
	}
	}
	else if (intf.first == FILEPATH_IFACE)
	{
	for (const auto& property : intf.second)
	{
	if (property.first == "Path")
	{
	filePath = variant_ns::get<std::string>(property.second);
	}
	}
	}
	}
	if ((filePath.empty()) \|\| (purpose == VersionPurpose::Unknown))
	{
	return;
	}

	// Version id is the last item in the path
	auto pos = path.rfind("/");
	if (pos == std::string::npos)
	{
	log<level::ERR>("No version id found in object path",
	entry("OBJPATH=%s", path));
	return;
	}

	auto versionId = path.substr(pos + 1);

	if (activations.find(versionId) == activations.end())
	{
	// Determine the Activation state by processing the given image dir.
	auto activationState = server::Activation::Activations::Invalid;
	AssociationList associations = {};
	if (ItemUpdater::validateSquashFSImage(filePath) == 0)
	{
	activationState = server::Activation::Activations::Ready;
	// Create an association to the host inventory item
	associations.emplace_back(std::make_tuple(
	ACTIVATION_FWD_ASSOCIATION,
	ACTIVATION_REV_ASSOCIATION,
	HOST_INVENTORY_PATH));
	}

	fs::path manifestPath(filePath);
	manifestPath /= MANIFEST_FILE;
	std::string extendedVersion = (Version::getValue(manifestPath.string(),
	std::map<std::string, std::string>
	{{"extended_version", ""}})).begin()->second;

	activations.insert(std::make_pair(
	versionId,
	std::make_unique<Activation>(
	bus,
	path,
	*this,
	versionId,
	extendedVersion,
	activationState,
	associations)));
	versions.insert(std::make_pair(
	versionId,
	std::make_unique<Version>(
	bus,
	path,
	version,
	purpose,
	filePath)));
	}
	return;
	}

	void ItemUpdater::processPNORImage()
	{
	// Read pnor.toc from folders under /media/
	// to get Active Software Versions.
	for (const auto& iter : fs::directory_iterator(MEDIA_DIR))
	{
	auto activationState = server::Activation::Activations::Active;

	static const auto PNOR_RO_PREFIX_LEN = strlen(PNOR_RO_PREFIX);
	static const auto PNOR_RW_PREFIX_LEN = strlen(PNOR_RW_PREFIX);

	// Check if the PNOR_RO_PREFIX is the prefix of the iter.path
	if (0 == iter.path().native().compare(0, PNOR_RO_PREFIX_LEN,
	PNOR_RO_PREFIX))
	{
	// The versionId is extracted from the path
	// for example /media/pnor-ro-2a1022fe.
	auto id = iter.path().native().substr(PNOR_RO_PREFIX_LEN);
	auto pnorTOC = iter.path() / PNOR_TOC_FILE;
	if (!fs::is_regular_file(pnorTOC))
	{
	log<level::ERR>("Failed to read pnorTOC.",
	entry("FILENAME=%s", pnorTOC.string()));
	ItemUpdater::erase(id);
	continue;
	}
	auto keyValues =
	Version::getValue(pnorTOC,
	{{ "version", "" },
	{ "extended_version", "" } });
	auto& version = keyValues.at("version");
	if (version.empty())
	{
	log<level::ERR>("Failed to read version from pnorTOC",
	entry("FILENAME=%s", pnorTOC.string()));
	activationState = server::Activation::Activations::Invalid;
	}

	auto& extendedVersion = keyValues.at("extended_version");
	if (extendedVersion.empty())
	{
	log<level::ERR>("Failed to read extendedVersion from pnorTOC",
	entry("FILENAME=%s", pnorTOC.string()));
	activationState = server::Activation::Activations::Invalid;
	}

	auto purpose = server::Version::VersionPurpose::Host;
	auto path = fs::path(SOFTWARE_OBJPATH) / id;
	AssociationList associations = {};

	if (activationState == server::Activation::Activations::Active)
	{
	// Create an association to the host inventory item
	associations.emplace_back(std::make_tuple(
	ACTIVATION_FWD_ASSOCIATION,
	ACTIVATION_REV_ASSOCIATION,
	HOST_INVENTORY_PATH));

	// Create an active association since this image is active
	createActiveAssociation(path);
	}

	// Create Activation instance for this version.
	activations.insert(std::make_pair(
	id,
	std::make_unique<Activation>(
	bus,
	path,
	*this,
	id,
	extendedVersion,
	activationState,
	associations)));

	// If Active, create RedundancyPriority instance for this version.
	if (activationState == server::Activation::Activations::Active)
	{
	uint8_t priority = std::numeric_limits<uint8_t>::max();
	if (!restoreFromFile(id, priority))
	{
	log<level::ERR>("Unable to restore priority from file.",
	entry("VERSIONID=%s", id));
	}
	activations.find(id)->second->redundancyPriority =
	std::make_unique<RedundancyPriority>(
	bus,
	path,
	*(activations.find(id)->second),
	priority);
	}

	// Create Version instance for this version.
	versions.insert(std::make_pair(
	id,
	std::make_unique<Version>(
	bus,
	path,
	version,
	purpose,
	"")));
	}
	else if (0 == iter.path().native().compare(0, PNOR_RW_PREFIX_LEN,
	PNOR_RW_PREFIX))
	{
	auto id = iter.path().native().substr(PNOR_RW_PREFIX_LEN);
	auto roDir = PNOR_RO_PREFIX + id;
	if (!fs::is_directory(roDir))
	{
	log<level::ERR>("No corresponding read-only volume found.",
	entry("DIRNAME=%s", roDir));
	ItemUpdater::erase(id);
	}
	}
	}

	// Look at the RO symlink to determine if there is a functional image
	auto id = determineId(PNOR_RO_ACTIVE_PATH);
	if (!id.empty())
	{
	updateFunctionalAssociation(std::string{SOFTWARE_OBJPATH} + '/' + id);
	}
	return;
	}

	int ItemUpdater::validateSquashFSImage(const std::string& filePath)
	{
	auto file = fs::path(filePath) / squashFSImage;
	if (fs::is_regular_file(file))
	{
	return 0;
	}
	else
	{
	log<level::ERR>("Failed to find the SquashFS image.");
	return -1;
	}
	}

	void ItemUpdater::removeReadOnlyPartition(std::string versionId)
	{
	auto serviceFile = "obmc-flash-bios-ubiumount-ro@" + versionId +
	".service";

	// Remove the read-only partitions.
	auto method = bus.new_method_call(
	SYSTEMD_BUSNAME,
	SYSTEMD_PATH,
	SYSTEMD_INTERFACE,
	"StartUnit");
	method.append(serviceFile, "replace");
	bus.call_noreply(method);
	}

	void ItemUpdater::removeReadWritePartition(std::string versionId)
	{
	auto serviceFile = "obmc-flash-bios-ubiumount-rw@" + versionId +
	".service";

	// Remove the read-write partitions.
	auto method = bus.new_method_call(
	SYSTEMD_BUSNAME,
	SYSTEMD_PATH,
	SYSTEMD_INTERFACE,
	"StartUnit");
	method.append(serviceFile, "replace");
	bus.call_noreply(method);
	}

	void ItemUpdater::reset()
	{
	for (const auto& it : activations)
	{
	auto serviceFile = "obmc-flash-bios-ubiclear@pnor-rw-" + it.first +
	".service";

	// Clear the read-write partitions.
	auto method = bus.new_method_call(
	SYSTEMD_BUSNAME,
	SYSTEMD_PATH,
	SYSTEMD_INTERFACE,
	"StartUnit");
	method.append(serviceFile, "replace");
	auto reply = bus.call(method);

	if (reply.is_method_error())
	{
	log<level::ERR>("Failed to clear read-write partitions",
	entry("SERVICE_FILE=%s", serviceFile));
	elog<InternalFailure>();
	}

	removeFile(it.first);
	}
	static constexpr auto serviceFile =
	"obmc-flash-bios-ubiclear@pnor-prsv.service";
	// Clear the preserved partition.
	auto method = bus.new_method_call(
	SYSTEMD_BUSNAME,
	SYSTEMD_PATH,
	SYSTEMD_INTERFACE,
	"StartUnit");
	method.append(serviceFile, "replace");
	auto reply = bus.call(method);

	if (reply.is_method_error())
	{
	log<level::ERR>("Failed to clear preserved partition",
	entry("SERVICE_FILE=%s", serviceFile));
	elog<InternalFailure>();
	}

	return;
	}

	bool ItemUpdater::isVersionFunctional(std::string versionId)
	{
	if (!fs::exists(PNOR_RO_ACTIVE_PATH))
	{
	return false;
	}

	fs::path activeRO = fs::read_symlink(PNOR_RO_ACTIVE_PATH);

	if (!fs::is_directory(activeRO))
	{
	return false;
	}

	if (activeRO.string().find(versionId) == std::string::npos)
	{
	return false;
	}

	// active PNOR is the version we're checking
	return true;
	}

	bool ItemUpdater::isChassisOn()
	{
	auto mapperCall = bus.new_method_call(
	MAPPER_BUSNAME,
	MAPPER_PATH,
	MAPPER_INTERFACE,
	"GetObject");

	mapperCall.append(CHASSIS_STATE_PATH,
	std::vector<std::string>({CHASSIS_STATE_OBJ}));
	auto mapperResponseMsg = bus.call(mapperCall);
	if (mapperResponseMsg.is_method_error())
	{
	log<level::ERR>("Error in Mapper call");
	elog<InternalFailure>();
	}
	using MapperResponseType = std::map<std::string, std::vector<std::string>>;
	MapperResponseType mapperResponse;
	mapperResponseMsg.read(mapperResponse);
	if (mapperResponse.empty())
	{
	log<level::ERR>("Invalid Response from mapper");
	elog<InternalFailure>();
	}

	auto method = bus.new_method_call((mapperResponse.begin()->first).c_str(),
	CHASSIS_STATE_PATH,
	SYSTEMD_PROPERTY_INTERFACE,
	"Get");
	method.append(CHASSIS_STATE_OBJ, "CurrentPowerState");
	auto response = bus.call(method);
	if (response.is_method_error())
	{
	log<level::ERR>("Error in fetching current Chassis State",
	entry("MAPPERRESPONSE=%s",
	(mapperResponse.begin()->first).c_str()));
	elog<InternalFailure>();
	}
	sdbusplus::message::variant<std::string> currentChassisState;
	response.read(currentChassisState);
	auto strParam =
	sdbusplus::message::variant_ns::get<std::string>(currentChassisState);
	return (strParam != CHASSIS_STATE_OFF);
	}

	void ItemUpdater::freePriority(uint8_t value, const std::string& versionId)
	{
	//TODO openbmc/openbmc#1896 Improve the performance of this function
	for (const auto& intf : activations)
	{
	if (intf.second->redundancyPriority)
	{
	if (intf.second->redundancyPriority.get()->priority() == value &&
	intf.second->versionId != versionId)
	{
	intf.second->redundancyPriority.get()->priority(value + 1);
	}
	}
	}
	}

	bool ItemUpdater::isLowestPriority(uint8_t value)
	{
	for (const auto& intf : activations)
	{
	if (intf.second->redundancyPriority)
	{
	if (intf.second->redundancyPriority.get()->priority() < value)
	{
	return false;
	}
	}
	}
	return true;
	}

	void ItemUpdater::erase(std::string entryId)
	{
	if (isVersionFunctional(entryId) && isChassisOn()) {
	log<level::ERR>(("Error: Version " + entryId + \
	" is currently active and running on the host." \
	" Unable to remove.").c_str());
	return;
	}
	// Remove priority persistence file
	removeFile(entryId);

	// Removing read-only and read-write partitions
	removeReadWritePartition(entryId);
	removeReadOnlyPartition(entryId);

	// Removing entry in versions map
	auto it = versions.find(entryId);
	if (it == versions.end())
	{
	log<level::ERR>(("Error: Failed to find version " + entryId + \
	" in item updater versions map." \
	" Unable to remove.").c_str());
	return;
	}
	versions.erase(entryId);

	// Removing entry in activations map
	auto ita = activations.find(entryId);
	if (ita == activations.end())
	{
	log<level::ERR>(("Error: Failed to find version " + entryId + \
	" in item updater activations map." \
	" Unable to remove.").c_str());
	return;
	}
	activations.erase(entryId);
	}

	void ItemUpdater::deleteAll()
	{
	std::vector<std::string> deletableActivations;

	for (const auto& activationIt : activations)
	{
	if (!isVersionFunctional(activationIt.first))
	{
	deletableActivations.push_back(activationIt.first);
	}
	}

	for (const auto& deletableIt : deletableActivations)
	{
	ItemUpdater::erase(deletableIt);
	}

	// Remove any remaining pnor-ro- or pnor-rw- volumes that do not match
	// the current version.
	auto method = bus.new_method_call(
	SYSTEMD_BUSNAME,
	SYSTEMD_PATH,
	SYSTEMD_INTERFACE,
	"StartUnit");
	method.append("obmc-flash-bios-cleanup.service", "replace");
	bus.call_noreply(method);
	}

	// TODO: openbmc/openbmc#1402 Monitor flash usage
	void ItemUpdater::freeSpace()
	{
	std::size_t count = 0;
	decltype(activations.begin()->second->redundancyPriority.get()->priority())
	highestPriority = 0;
	decltype(activations.begin()->second->versionId) highestPriorityVersion;
	for (const auto& iter : activations)
	{
	if (iter.second.get()->activation() == server::Activation::Activations::Active)
	{
	count++;
	if (isVersionFunctional(iter.second->versionId))
	{
	continue;
	}
	if (iter.second->redundancyPriority.get()->priority() >= highestPriority)
	{
	highestPriority = iter.second->redundancyPriority.get()->priority();
	highestPriorityVersion = iter.second->versionId;
	}
	}
	}
	// Remove the pnor version with highest priority since the PNOR
	// can't hold more than 2 versions.
	if (count >= ACTIVE_PNOR_MAX_ALLOWED)
	{
	erase(highestPriorityVersion);
	}
	}

	void ItemUpdater::createActiveAssociation(const std::string& path)
	{
	assocs.emplace_back(std::make_tuple(ACTIVE_FWD_ASSOCIATION,
	ACTIVE_REV_ASSOCIATION,
	path));
	associations(assocs);
	}

	void ItemUpdater::updateFunctionalAssociation(const std::string& path)
	{
	// remove all functional associations
	for (auto iter = assocs.begin(); iter != assocs.end();)
	{
	if ((std::get<0>(*iter)).compare(FUNCTIONAL_FWD_ASSOCIATION) == 0)
	{
	iter = assocs.erase(iter);
	}
	else
	{
	++iter;
	}
	}
	assocs.emplace_back(std::make_tuple(FUNCTIONAL_FWD_ASSOCIATION,
	FUNCTIONAL_REV_ASSOCIATION,
	path));
	associations(assocs);
	}

	void ItemUpdater::removeActiveAssociation(const std::string& path)
	{
	for (auto iter = assocs.begin(); iter != assocs.end();)
	{
	if ((std::get<0>(*iter)).compare(ACTIVE_FWD_ASSOCIATION) == 0 &&
	(std::get<2>(*iter)).compare(path) == 0)
	{
	iter = assocs.erase(iter);
	associations(assocs);
	}
	else
	{
	++iter;
	}
	}
	}

	std::string ItemUpdater::determineId(const std::string& symlinkPath)
	{
	if (!fs::exists(symlinkPath))
	{
	return {};
	}

	auto target = fs::canonical(symlinkPath).string();

	// check to make sure the target really exists
	if (!fs::is_regular_file(target + "/" + PNOR_TOC_FILE))
	{
	return {};
	}
	// Get the image <id> from the symlink target
	// for example /media/ro-2a1022fe
	static const auto PNOR_RO_PREFIX_LEN = strlen(PNOR_RO_PREFIX);
	return target.substr(PNOR_RO_PREFIX_LEN);
	}

	void GardReset::reset()
	{
	// The GARD partition is currently misspelled "GUARD." This file path will
	// need to be updated in the future.
	auto path = fs::path(PNOR_PRSV_ACTIVE_PATH);
	path /= "GUARD";
	std::vector<uint8_t> mboxdArgs;

	auto dbusCall = bus.new_method_call(
	MBOXD_INTERFACE,
	MBOXD_PATH,
	MBOXD_INTERFACE,
	"cmd");

	// Suspend mboxd - no args required.
	dbusCall.append(static_cast<uint8_t>(3), mboxdArgs);

	auto responseMsg = bus.call(dbusCall);
	if (responseMsg.is_method_error())
	{
	log<level::ERR>("Error in mboxd suspend call");
	elog<InternalFailure>();
	}

	if (fs::is_regular_file(path))
	{
	fs::remove(path);
	}

	dbusCall = bus.new_method_call(
	MBOXD_INTERFACE,
	MBOXD_PATH,
	MBOXD_INTERFACE,
	"cmd");

	// Resume mboxd with arg 1, indicating that the flash is modified.
	mboxdArgs.push_back(1);
	dbusCall.append(static_cast<uint8_t>(4), mboxdArgs);

	responseMsg = bus.call(dbusCall);
	if (responseMsg.is_method_error())
	{
	log<level::ERR>("Error in mboxd resume call");
	elog<InternalFailure>();
	}
	}

	} // namespace updater
	} // namespace software
	} // namespace openpower