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

 #include "config.h"

 #include "item_updater.hpp"

 #include "activation.hpp"
 #include "serialize.hpp"
 #include "version.hpp"
 #include "xyz/openbmc_project/Common/error.hpp"

 #include <experimental/filesystem>
 #include <fstream>
 #include <phosphor-logging/elog-errors.hpp>
 #include <phosphor-logging/log.hpp>
 #include <queue>
 #include <string>
 #include <xyz/openbmc_project/Software/Version/server.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";

 // 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.c_str()));
         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)));

         auto versionPtr = std::make_unique<Version>(
             bus, path, *this, versionId, version, purpose, filePath,
             std::bind(&ItemUpdater::erase, this, std::placeholders::_1));
         versionPtr->deleteObject =
             std::make_unique<Delete>(bus, path, *versionPtr);
         versions.insert(std::make_pair(versionId, std::move(versionPtr)));
     }
     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.c_str()));
                 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.c_str()));
                 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.c_str()));
                 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.c_str()));
                 }
                 activations.find(id)->second->redundancyPriority =
                     std::make_unique<RedundancyPriority>(
                         bus, path, *(activations.find(id)->second), priority);
             }

             // Create Version instance for this version.
             auto versionPtr = std::make_unique<Version>(
                 bus, path, *this, id, version, purpose, "",
                 std::bind(&ItemUpdater::erase, this, std::placeholders::_1));
             versionPtr->deleteObject =
                 std::make_unique<Delete>(bus, path, *versionPtr);
             versions.insert(std::make_pair(id, std::move(versionPtr)));
         }
         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.c_str()));
                 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()
 {
     std::vector<uint8_t> mboxdArgs;

     // Suspend mboxd - no args required.
     auto dbusCall = bus.new_method_call(MBOXD_INTERFACE, MBOXD_PATH,
                                         MBOXD_INTERFACE, "cmd");

     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>();
     }

     constexpr static auto patchDir = "/usr/local/share/pnor";
     if (fs::is_directory(patchDir))
     {
         for (const auto& iter : fs::directory_iterator(patchDir))
         {
             fs::remove_all(iter);
         }
     }

     // Clear the read-write partitions.
     for (const auto& it : activations)
     {
         auto rwDir = PNOR_RW_PREFIX + it.first;
         if (fs::is_directory(rwDir))
         {
             for (const auto& iter : fs::directory_iterator(rwDir))
             {
                 fs::remove_all(iter);
             }
         }
     }

     // Clear the preserved partition.
     if (fs::is_directory(PNOR_PRSV))
     {
         for (const auto& iter : fs::directory_iterator(PNOR_PRSV))
         {
             fs::remove_all(iter);
         }
     }

     // Resume mboxd with arg 1, indicating that the flash was modified.
     dbusCall = bus.new_method_call(MBOXD_INTERFACE, MBOXD_PATH, MBOXD_INTERFACE,
                                    "cmd");

     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>();
     }

     return;
 }

 bool ItemUpdater::isVersionFunctional(const 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());
     }
     else
     {
         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());
     }
     else
     {
         removeAssociation(ita->second->path);
         activations.erase(entryId);
     }
     return;
 }

 void ItemUpdater::deleteAll()
 {
     auto chassisOn = isChassisOn();

     for (const auto& activationIt : activations)
     {
         if (isVersionFunctional(activationIt.first) && chassisOn)
         {
             continue;
         }
         else
         {
             ItemUpdater::erase(activationIt.first);
         }
     }

     // 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()
 {
     //  Versions with the highest priority in front
     std::priority_queue<std::pair<int, std::string>,
                         std::vector<std::pair<int, std::string>>,
                         std::less<std::pair<int, std::string>>>
         versionsPQ;

     std::size_t count = 0;
     for (const auto& iter : activations)
     {
         if (iter.second.get()->activation() ==
             server::Activation::Activations::Active)
         {
             count++;
             // Don't put the functional version on the queue since we can't
             // remove the "running" PNOR version.
             if (isVersionFunctional(iter.second->versionId))
             {
                 continue;
             }
             versionsPQ.push(std::make_pair(
                 iter.second->redundancyPriority.get()->priority(),
                 iter.second->versionId));
         }
     }

     // If the number of PNOR versions is over ACTIVE_PNOR_MAX_ALLOWED -1,
     // remove the highest priority one(s).
     while ((count >= ACTIVE_PNOR_MAX_ALLOWED) && (!versionsPQ.empty()))
     {
         erase(versionsPQ.top().second);
         versionsPQ.pop();
         count--;
     }
 }

 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::removeAssociation(const std::string& path)
 {
     for (auto iter = assocs.begin(); iter != assocs.end();)
     {
         if ((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 "config.h"

	#include "item_updater.hpp"

	#include "activation.hpp"
	#include "serialize.hpp"
	#include "version.hpp"
	#include "xyz/openbmc_project/Common/error.hpp"

	#include <experimental/filesystem>
	#include <fstream>
	#include <phosphor-logging/elog-errors.hpp>
	#include <phosphor-logging/log.hpp>
	#include <queue>
	#include <string>
	#include <xyz/openbmc_project/Software/Version/server.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";

	// 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.c_str()));
	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)));

	auto versionPtr = std::make_unique<Version>(
	bus, path, *this, versionId, version, purpose, filePath,
	std::bind(&ItemUpdater::erase, this, std::placeholders::_1));
	versionPtr->deleteObject =
	std::make_unique<Delete>(bus, path, *versionPtr);
	versions.insert(std::make_pair(versionId, std::move(versionPtr)));
	}
	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.c_str()));
	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.c_str()));
	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.c_str()));
	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.c_str()));
	}
	activations.find(id)->second->redundancyPriority =
	std::make_unique<RedundancyPriority>(
	bus, path, *(activations.find(id)->second), priority);
	}

	// Create Version instance for this version.
	auto versionPtr = std::make_unique<Version>(
	bus, path, *this, id, version, purpose, "",
	std::bind(&ItemUpdater::erase, this, std::placeholders::_1));
	versionPtr->deleteObject =
	std::make_unique<Delete>(bus, path, *versionPtr);
	versions.insert(std::make_pair(id, std::move(versionPtr)));
	}
	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.c_str()));
	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()
	{
	std::vector<uint8_t> mboxdArgs;

	// Suspend mboxd - no args required.
	auto dbusCall = bus.new_method_call(MBOXD_INTERFACE, MBOXD_PATH,
	MBOXD_INTERFACE, "cmd");

	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>();
	}

	constexpr static auto patchDir = "/usr/local/share/pnor";
	if (fs::is_directory(patchDir))
	{
	for (const auto& iter : fs::directory_iterator(patchDir))
	{
	fs::remove_all(iter);
	}
	}

	// Clear the read-write partitions.
	for (const auto& it : activations)
	{
	auto rwDir = PNOR_RW_PREFIX + it.first;
	if (fs::is_directory(rwDir))
	{
	for (const auto& iter : fs::directory_iterator(rwDir))
	{
	fs::remove_all(iter);
	}
	}
	}

	// Clear the preserved partition.
	if (fs::is_directory(PNOR_PRSV))
	{
	for (const auto& iter : fs::directory_iterator(PNOR_PRSV))
	{
	fs::remove_all(iter);
	}
	}

	// Resume mboxd with arg 1, indicating that the flash was modified.
	dbusCall = bus.new_method_call(MBOXD_INTERFACE, MBOXD_PATH, MBOXD_INTERFACE,
	"cmd");

	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>();
	}

	return;
	}

	bool ItemUpdater::isVersionFunctional(const 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());
	}
	else
	{
	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());
	}
	else
	{
	removeAssociation(ita->second->path);
	activations.erase(entryId);
	}
	return;
	}

	void ItemUpdater::deleteAll()
	{
	auto chassisOn = isChassisOn();

	for (const auto& activationIt : activations)
	{
	if (isVersionFunctional(activationIt.first) && chassisOn)
	{
	continue;
	}
	else
	{
	ItemUpdater::erase(activationIt.first);
	}
	}

	// 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()
	{
	// Versions with the highest priority in front
	std::priority_queue<std::pair<int, std::string>,
	std::vector<std::pair<int, std::string>>,
	std::less<std::pair<int, std::string>>>
	versionsPQ;

	std::size_t count = 0;
	for (const auto& iter : activations)
	{
	if (iter.second.get()->activation() ==
	server::Activation::Activations::Active)
	{
	count++;
	// Don't put the functional version on the queue since we can't
	// remove the "running" PNOR version.
	if (isVersionFunctional(iter.second->versionId))
	{
	continue;
	}
	versionsPQ.push(std::make_pair(
	iter.second->redundancyPriority.get()->priority(),
	iter.second->versionId));
	}
	}

	// If the number of PNOR versions is over ACTIVE_PNOR_MAX_ALLOWED -1,
	// remove the highest priority one(s).
	while ((count >= ACTIVE_PNOR_MAX_ALLOWED) && (!versionsPQ.empty()))
	{
	erase(versionsPQ.top().second);
	versionsPQ.pop();
	count--;
	}
	}

	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::removeAssociation(const std::string& path)
	{
	for (auto iter = assocs.begin(); iter != assocs.end();)
	{
	if ((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