From b82e547b53f2998b491ab471ee84519fd7d949b0 Mon Sep 17 00:00:00 2001
From: Florian Lukas <florian.lukas@gmail.com>
Date: Tue, 18 Feb 2014 16:28:42 +0100
Subject: [PATCH] plugins/randomgenerator: add deterministic PRNG plugin

A simple plugin which deterministically returns a new random value
each time the specified symbol is read.

Change-Id: I6ccac421fc064f02a88e8b126f8a26044d1f51c6
---
 src/plugins/randomgenerator/CMakeLists.txt    | 10 +++++
 .../randomgenerator/RandomGenerator.cc        | 25 ++++++++++++
 .../randomgenerator/RandomGenerator.hpp       | 38 +++++++++++++++++++
 3 files changed, 73 insertions(+)
 create mode 100644 src/plugins/randomgenerator/CMakeLists.txt
 create mode 100644 src/plugins/randomgenerator/RandomGenerator.cc
 create mode 100644 src/plugins/randomgenerator/RandomGenerator.hpp

diff --git a/src/plugins/randomgenerator/CMakeLists.txt b/src/plugins/randomgenerator/CMakeLists.txt
new file mode 100644
index 00000000..5a9af4f6
--- /dev/null
+++ b/src/plugins/randomgenerator/CMakeLists.txt
@@ -0,0 +1,10 @@
+set(PLUGIN_NAME randomgenerator)
+
+set(MY_PLUGIN_SRCS
+  RandomGenerator.cc
+  RandomGenerator.hpp
+)
+include_directories(${CMAKE_CURRENT_BINARY_DIR})
+
+## Build library
+add_library(fail-${PLUGIN_NAME} ${MY_PLUGIN_SRCS})
diff --git a/src/plugins/randomgenerator/RandomGenerator.cc b/src/plugins/randomgenerator/RandomGenerator.cc
new file mode 100644
index 00000000..100a9b4e
--- /dev/null
+++ b/src/plugins/randomgenerator/RandomGenerator.cc
@@ -0,0 +1,25 @@
+#include "RandomGenerator.hpp"
+#include "sal/Listener.hpp"
+#include "sal/Memory.hpp"
+
+using namespace std;
+using namespace fail;
+
+bool RandomGenerator::run()
+{
+	m_log << "RandomGenerator started. @ " << m_symbol << std::endl;
+
+	MemoryManager& mm = simulator.getMemoryManager();
+	MemReadListener l_mem(m_symbol.getAddress());
+
+	uint32_t value = m_seed;
+
+	while (true) {
+		simulator.addListenerAndResume(&l_mem);
+
+		value = value * 1103515245 + 12345;
+
+		mm.setBytes(m_symbol.getAddress(), sizeof(value), &value);
+	}
+	return true;
+}
diff --git a/src/plugins/randomgenerator/RandomGenerator.hpp b/src/plugins/randomgenerator/RandomGenerator.hpp
new file mode 100644
index 00000000..54154272
--- /dev/null
+++ b/src/plugins/randomgenerator/RandomGenerator.hpp
@@ -0,0 +1,38 @@
+#ifndef __RandomGenerator_HPP__
+#define __RandomGenerator_HPP__
+
+#include <unistd.h>
+#include "efw/ExperimentFlow.hpp"
+#include "config/FailConfig.hpp"
+#include "util/Logger.hpp"
+#include "util/ElfReader.hpp"
+#include <math.h>
+
+/**
+ * @file
+ * @brief A deterministic pseudo-random number generator
+ */
+
+/**
+ * @class RandomGenerator
+ * @brief Plugin to provide deterministic pseudo-random numbers on a specific memory location
+ */
+class RandomGenerator : public fail::ExperimentFlow
+{
+private:
+	const fail::ElfSymbol m_symbol; //!< the target's memory symbol the plugin is listening on to generate value
+	fail::Logger m_log; //!< debug output
+	const unsigned m_seed; //!< PRNG seed value
+public:
+	/**
+	 * Constructor
+	 *
+	 * @param symbol The resulting random is placed in the SUT symbol
+	 * @param seed seed value for PRNG
+	 */
+	RandomGenerator( const fail::ElfSymbol & symbol, unsigned seed ) :   m_symbol(symbol), m_log("RandGen", false), m_seed(seed){}
+
+	bool run();
+};
+
+#endif // __RandomGenerator_HPP__