PEL: Add ExtendedUserHeader section class

This is a required PEL section.

The section contains:
* The machine type/model/SN
* The server firmware version
* The BMC firmware version
* The 'Event Common Reference Time' (not used yet)
* The symptom ID (a unique event signature)

Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: I223041f85965195fccf69542dbe86ce856073b36
diff --git a/extensions/openpower-pels/extended_user_header.cpp b/extensions/openpower-pels/extended_user_header.cpp
new file mode 100644
index 0000000..c5c1938
--- /dev/null
+++ b/extensions/openpower-pels/extended_user_header.cpp
@@ -0,0 +1,179 @@
+/**
+ * Copyright © 2019 IBM Corporation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include "extended_user_header.hpp"
+
+#include "pel_types.hpp"
+
+#include <phosphor-logging/log.hpp>
+
+namespace openpower
+{
+namespace pels
+{
+
+using namespace phosphor::logging;
+const size_t defaultSymptomIDWord = 3;
+const size_t symptomIDMaxSize = 80;
+
+ExtendedUserHeader::ExtendedUserHeader(Stream& pel)
+{
+    try
+    {
+        unflatten(pel);
+        validate();
+    }
+    catch (const std::exception& e)
+    {
+        log<level::ERR>("Cannot unflatten extended user header",
+                        entry("ERROR=%s", e.what()));
+        _valid = false;
+    }
+}
+
+ExtendedUserHeader::ExtendedUserHeader(const DataInterfaceBase& dataIface,
+                                       const message::Entry& regEntry,
+                                       const SRC& src) :
+    _mtms(dataIface.getMachineTypeModel(), dataIface.getMachineSerialNumber())
+{
+    _header.id = static_cast<uint16_t>(SectionID::extendedUserHeader);
+    _header.version = extendedUserHeaderVersion;
+    _header.subType = 0;
+    _header.componentID = static_cast<uint16_t>(ComponentID::phosphorLogging);
+
+    memset(_serverFWVersion.data(), 0, _serverFWVersion.size());
+    auto version = dataIface.getServerFWVersion();
+
+    // The last byte must always be the NULL terminator
+    for (size_t i = 0; i < version.size() && i < firmwareVersionSize - 1; i++)
+    {
+        _serverFWVersion[i] = version[i];
+    }
+
+    memset(_subsystemFWVersion.data(), 0, _subsystemFWVersion.size());
+    version = dataIface.getBMCFWVersion();
+
+    // The last byte must always be the NULL terminator
+    for (size_t i = 0; i < version.size() && i < firmwareVersionSize - 1; i++)
+    {
+        _subsystemFWVersion[i] = version[i];
+    }
+
+    createSymptomID(regEntry, src);
+
+    _header.size = flattenedSize();
+    _valid = true;
+}
+
+void ExtendedUserHeader::flatten(Stream& pel) const
+{
+    pel << _header << _mtms;
+    pel.write(_serverFWVersion.data(), _serverFWVersion.size());
+    pel.write(_subsystemFWVersion.data(), _subsystemFWVersion.size());
+    pel << _reserved4B << _refTime << _reserved1B1 << _reserved1B2
+        << _reserved1B3 << _symptomIDSize << _symptomID;
+}
+
+void ExtendedUserHeader::unflatten(Stream& pel)
+{
+    pel >> _header >> _mtms;
+    pel.read(_serverFWVersion.data(), _serverFWVersion.size());
+    pel.read(_subsystemFWVersion.data(), _subsystemFWVersion.size());
+    pel >> _reserved4B >> _refTime >> _reserved1B1 >> _reserved1B2 >>
+        _reserved1B3 >> _symptomIDSize;
+
+    _symptomID.resize(_symptomIDSize);
+    pel >> _symptomID;
+}
+
+void ExtendedUserHeader::validate()
+{
+    bool failed = false;
+
+    if (header().id != static_cast<uint16_t>(SectionID::extendedUserHeader))
+    {
+        log<level::ERR>("Invalid failing Extended User Header section ID",
+                        entry("ID=0x%X", header().id));
+        failed = true;
+    }
+
+    if (header().version != extendedUserHeaderVersion)
+    {
+        log<level::ERR>("Invalid Extended User Header version",
+                        entry("VERSION=0x%X", header().version));
+        failed = true;
+    }
+
+    _valid = (failed) ? false : true;
+}
+
+void ExtendedUserHeader::createSymptomID(const message::Entry& regEntry,
+                                         const SRC& src)
+{
+    // Contains the first 8 characters of the ASCII string plus additional
+    // words from the SRC, separated by underscores.  The message registry
+    // says which words to use, though that's optional and if not present
+    // then use a default word.
+    std::vector<size_t> idWords;
+
+    if (regEntry.src.symptomID)
+    {
+        idWords = regEntry.src.symptomID.value();
+    }
+    else
+    {
+        idWords.push_back(defaultSymptomIDWord);
+    }
+
+    auto symptomID = src.asciiString().substr(0, 8);
+
+    const auto& hexWords = src.hexwordData();
+
+    for (auto wordNum : idWords)
+    {
+        symptomID.push_back('_');
+
+        // Get the hexword array index for this SRC word
+        auto index = src.getWordIndexFromWordNum(wordNum);
+
+        // Convert to ASCII
+        char word[20];
+        sprintf(word, "%08X", hexWords[index]);
+        symptomID += word;
+    }
+
+    std::copy(symptomID.begin(), symptomID.end(),
+              std::back_inserter(_symptomID));
+
+    // Max total size is 80, including the upcoming NULL
+    if (_symptomID.size() > (symptomIDMaxSize - 1))
+    {
+        _symptomID.resize(symptomIDMaxSize - 1);
+    }
+
+    // NULL terminated
+    _symptomID.push_back(0);
+
+    // PAD with NULLs to a 4 byte boundary
+    while ((_symptomID.size() % 4) != 0)
+    {
+        _symptomID.push_back(0);
+    }
+
+    _symptomIDSize = _symptomID.size();
+}
+
+} // namespace pels
+} // namespace openpower