/// <summary>
///
/// </summary>
/// <param name="virtualMemSizeIn"></param>
public MemoryManager(uint virtualMemSizeIn)
{
//
// Find a size for addressableMemory that is on a page boundary
//
virtualMemSize = CPU.UtilRoundToBoundary(virtualMemSizeIn, CPU.pageSize);
//
// Size of memory must be a factor of CPU.pageSize
// This was asserted when the CPU initialized memory
//
uint physicalpages = (uint)(CPU.physicalMemory.Length / CPU.pageSize);
uint addressablepages = (uint)(virtualMemSize / CPU.pageSize);
_pageTable = new ArrayList((int)addressablepages);
// Delete all our Swap Files
foreach (string f in Directory.GetFiles(".", "*.xml"))
{
File.Delete(f);
}
// For all off addressable memory...
// Make the pages in physical and the pages that aren't in physical
for (uint i = 0; i < virtualMemSize; i += CPU.pageSize)
{
// Mark the Pages that are in physical memory as "false" or "not free"
MemoryPage p;
if (i < CPU.physicalMemory.Length)
{
p = new MemoryPage(i, true);
freePhysicalPages[(int)(i / CPU.pageSize)] = false;
}
else
{
p = new MemoryPage(i, false);
}
_pageTable.Add(p);
}
//
// Cordon off some shared memory regions...these are setting the AppSettings
//
uint SharedRegionsSize = uint.Parse(EntryPoint.Configuration["SharedMemoryRegionSize"]);
uint SharedRegions = uint.Parse(EntryPoint.Configuration["NumOfSharedMemoryRegions"]);
if (SharedRegions > 0 && SharedRegionsSize > 0)
{
uint TotalPagesNeeded = (uint)(SharedRegions * SharedRegionsSize / CPU.pageSize);
uint pagesPerRegion = TotalPagesNeeded / SharedRegions;
// ForExample:
// I need 2 regions
// 64 bytes needed for each
// 4 pages each
// 8 total pages needed
// Because I pre-allocate shared memory I'll have the luxury of contigous pages of memory.
// I'll exploit this hack in MapSharedMemoryToProcess
foreach (MemoryPage page in _pageTable)
{
// Do we still need pages?
if (TotalPagesNeeded > 0)
{
// If this page is assigned to the OS, take it
if (page.SharedMemoryRegion == 0)
{
// Now assign it to us
page.SharedMemoryRegion = SharedRegions;
TotalPagesNeeded--;
if (TotalPagesNeeded % pagesPerRegion == 0)
{
SharedRegions--;
}
}
}
else //We have all we need
{
break;
}
}
}
}
/// <summary>
/// Helper method to translate # of bytes to # of Memory Pages
/// </summary>
/// <param name="bytes">bytes to translate</param>
/// <returns>number of pages</returns>
public static uint BytesToPages(uint bytes)
{
return(CPU.UtilRoundToBoundary(bytes, CPU.pageSize) / CPU.pageSize);
//return ((uint)(bytes / CPU.pageSize) + (uint)(bytes % CPU.pageSize));
}
/// <summary>
/// Gets a 4 byte unsigned integer (typically an opCode param) from memory
/// </summary>
/// <param name="processid">The calling processid</param>
/// <param name="processIndex">The address in memory from the Process's point of view</param>
/// <returns></returns>
public uint getUIntFrom(uint processid, uint processIndex)
{
return(CPU.BytesToUInt(getBytesFrom(processid, processIndex, 4)));
}
/// <summary>
/// Sets a 4 byte unsigned integer (typically an opCode param) to memory
/// </summary>
/// <param name="processid">The calling processid</param>
/// <param name="processIndex">The address in memory from the Process's point of view</param>
/// <param name="avalue">The new value</param>
public void setUIntAt(uint processid, uint processIndex, uint avalue)
{
setBytesAt(processid, processIndex, CPU.UIntToBytes(avalue));
}
static void Main(string[] args)
{
var builder = new ConfigurationBuilder()
.AddJsonFile("appsettings.json");
Configuration = builder.Build();
OS theOS = null;
uint bytesOfVirtualMemory = 0;
uint bytesOfPhysicalMemory = 0;
PrintHeader();
if (args.Length < 2)
{
PrintInstructions();
}
else
{
//try
{
// Total addressable (virtual) memory taken from the command line
bytesOfVirtualMemory = uint.Parse(args[0]);
bytesOfPhysicalMemory = uint.Parse(Configuration["PhysicalMemory"]);
// Setup static physical memory
CPU.initPhysicalMemory(bytesOfPhysicalMemory);
// Create the OS and Memory Manager with Virtual Memory
theOS = new OS(bytesOfVirtualMemory);
// Let the CPU know about the OS
CPU.theOS = theOS;
Console.WriteLine("CPU has {0} bytes of physical memory", CPU.physicalMemory.Length);
Console.WriteLine("OS has {0} bytes of virtual (addressable) memory", theOS.memoryMgr.virtualMemSize);
// For each file on the command line, load the program and create a process
for (int i = 1; i < args.Length; i++)
{
if (File.Exists(args[i]))
{
Program p = Program.LoadProgram(args[i]);
Process rp = theOS.createProcess(p, uint.Parse(Configuration["ProcessMemory"]));
Console.WriteLine("Process id {0} has {1} bytes of process memory and {2} bytes of heap", rp.PCB.pid, Configuration["ProcessMemory"], rp.PCB.heapAddrEnd - rp.PCB.heapAddrStart);
p.DumpProgram();
}
}
// Start executing!
theOS.execute();
}
//catch (Exception e)
{
//PrintInstructions();
//Console.WriteLine(e.ToString());
}
// Pause
Console.WriteLine("OS execution complete. Press Enter to continue...");
Console.ReadLine();
}
}
