/// <summary>
/// Performs stage specific processing on the compiler context.
/// </summary>
/// <param name="compiler">The compiler context to perform processing in.</param>
public override void Run(CompilerFramework.AssemblyCompiler compiler)
{
if (String.IsNullOrEmpty(OutputFile))
{
throw new ArgumentException(@"Invalid argument.", "compiler");
}
// Layout the _sections in memory
LayoutSections();
// Resolve all symbols first
base.Run(compiler);
// Persist the Elf32 file now
CreateElf32File(compiler);
}
/// <summary>
/// Creates the elf32 file.
/// </summary>
/// <param name="compiler">The compiler.</param>
private void CreateElf32File(CompilerFramework.AssemblyCompiler compiler)
{
using (System.IO.FileStream fs = new System.IO.FileStream(OutputFile, System.IO.FileMode.Create, System.IO.FileAccess.Write, System.IO.FileShare.None)) {
Elf32Header header = new Elf32Header();
header.Type = Elf32FileType.Executable;
header.Machine = Elf32MachineType.Intel386;
header.SectionHeaderNumber = (ushort)(Sections.Count + 2);
header.SectionHeaderOffset = header.ElfHeaderSize;
header.CreateIdent(Elf32IdentClass.Class32, Elf32IdentData.Data2LSB, null);
// Calculate the concatenated size of all section's data
uint offset = 0;
foreach (Elf32Section section in Sections)
{
offset += (uint)section.Length;
}
offset += (uint)_nullSection.Length;
offset += (uint)_stringTableSection.Length;
// Calculate offsets
header.ProgramHeaderOffset = header.ElfHeaderSize + header.SectionHeaderEntrySize * (uint)header.SectionHeaderNumber + offset;
header.ProgramHeaderNumber = 1;
header.SectionHeaderStringIndex = 1;
System.IO.BinaryWriter writer = new System.IO.BinaryWriter(fs);
// Write the ELF Header
header.Write(writer);
// Overjump the Section Header Table and write the section's data first
long tmp = fs.Position;
writer.Seek((int)(tmp + header.SectionHeaderNumber * header.SectionHeaderEntrySize), System.IO.SeekOrigin.Begin);
_nullSection.Write(writer);
_stringTableSection.Write(writer);
// Write the _sections
foreach (Elf32Section section in Sections)
{
section.Write(writer);
}
// Jump back to the Section Header Table
writer.Seek((int)tmp, System.IO.SeekOrigin.Begin);
_nullSection.WriteHeader(writer);
_stringTableSection.WriteHeader(writer);
// Write the section headers
foreach (Elf32Section section in Sections)
{
section.WriteHeader(writer);
}
Elf32ProgramHeader pheader = new Elf32ProgramHeader
{
Alignment = 0,
FileSize = (uint)GetSection(SectionKind.Text).Length
};
pheader.MemorySize = pheader.FileSize;
pheader.VirtualAddress = 0xFF0000;
pheader.Flags = Elf32ProgramHeaderFlags.Execute | Elf32ProgramHeaderFlags.Read | Elf32ProgramHeaderFlags.Write;
pheader.Offset = ((Elf32Section)GetSection(SectionKind.Text)).Header.Offset;
pheader.Type = Elf32ProgramHeaderType.Load;
writer.Seek((int)header.ProgramHeaderOffset, System.IO.SeekOrigin.Begin);
pheader.Write(writer);
}
}
