private void AddCode(ElfFile file, AsmContext context)
{
if (context.CodeSection.VirtualSize > 0) {
file.Sections.Add(new ElfSection {
Name = file.Strings.SaveString(".text"),
Type = ElfSectionType.ProgBits,
Address = 0,
Flags = ElfSectionFlags.Alloc | ElfSectionFlags.Executable,
Size = (uint)context.CodeSection.BytesCount,
Align = 2,
Offset = (uint)file.Data.Position
});
file.Segments.Add(new ElfSegment {
Type = ElfSegmentType.Load,
Offset = (uint)file.Data.Position,
VirtualAddress = 0,
PhysicalAddress = 0,
FileSize = (uint)context.CodeSection.BytesCount,
MemorySize = (uint)context.CodeSection.VirtualSize,
Flags = ElfSegmentFlags.Executable | ElfSegmentFlags.Readable,
Align = 1
});
file.Data.Write(context.CodeSection.Content.ToArray(), 0, context.CodeSection.BytesCount);
}
}
public void SaveElf(AsmContext context, string fileName)
{
using (var file = File.Open(fileName, FileMode.Create, FileAccess.ReadWrite, FileShare.Read)) {
SaveElf(context, file);
file.Flush();
file.Close();
}
}
public void Save(AsmContext context, Stream stream)
{
var file = new ElfFile();
var writer = new BinaryWriter(stream);
file.Sections.Add(new ElfSection());
AddCode(file, context);
AddData(file, context);
AddFlash(file, context);
AddDebugLine(file, context);
var sectionsStringsIndex = file.AddStringsSection();
const int headerSize = 0x34;
const int segmentsOffset = headerSize;
const int segmentEntrySize = 0x20;
var dataOffset = (uint)(segmentsOffset + file.Segments.Count * segmentEntrySize);
var sectionsOffset = dataOffset + file.Data.Length;
var header = new ElfHeader {
Identification = {
Magic = new[] { (char)0x7f, 'E', 'L', 'F' },
FileClass = ElfFileClass.Elf32,
DataType = ElfDataType.Lsb,
Version = 1,
},
Type = ElfType.Executable,
Machine = 0x53,
Version = 1,
Entry = 0x0,
ProgramHeaderOffset = segmentsOffset,
SectionHeaderOffset = (uint)sectionsOffset,
Flags = 0x84,
ElfHeaderSize = headerSize,
ProgramHeaderEntrySize = segmentEntrySize,
ProgramHeaderCount = (ushort)file.Segments.Count,
SectionHeaderEntrySize = 0x28,
SectionHeaderCount = (ushort)file.Sections.Count,
StringSectionIndex = (ushort)sectionsStringsIndex
};
writer.WriteElf32(header);
foreach (var segment in file.Segments) {
var cloned = segment;
cloned.Offset += dataOffset;
writer.WriteElf32(cloned);
}
writer.Write(file.Data.ToArray());
foreach (var section in file.Sections) {
var cloned = section;
if (section.Type != ElfSectionType.Null) {
cloned.Offset += dataOffset;
}
writer.WriteElf32(cloned);
}
}
public AsmContext Assemble(string content, string fileName = null)
{
var symbols = new AsmSymbols();
IList<Token> tokens = new List<Token>();
LoadRecursive(content, tokens, fileName);
tokens = ProcessSymbolConstants(tokens, symbols);
AsmContext last = null;
for (var i = 1; i < 10; i++) {
var context = new AsmContext {
Queue = new TokensQueue(tokens),
Symbols = symbols,
Pass = i
};
var parser = new AsmParser(context);
AssemblePass(context, parser);
if (TheSame(last, context)) break;
last = context;
}
return last;
}
public AsmParser(AsmContext context)
{
_context = context;
_calculator = new ExpressionCalculator(context);
}
private void AddDebugLine(ElfFile file, AsmContext context)
{
var mem = new MemoryStream();
var writer = new BinaryWriter(mem);
var hdr = new DebugLineHeader {
FileNames = new[]
{
new DebugLineFile {Name = "test.asm"},
new DebugLineFile {Name = "test2.asm"},
}
};
writer.WriteDwarf2(hdr);
if (mem.Length > 0) {
file.Sections.Add(new ElfSection {
Name = file.Strings.SaveString(".debug_line"),
Type = ElfSectionType.ProgBits,
Address = 0,
Flags = ElfSectionFlags.None,
Size = (uint)mem.Length,
Align = 1,
Offset = (uint)file.Data.Position
});
file.Data.Write(mem.ToArray(), 0, (int)mem.Length);
}
}
public void SaveElf(AsmContext context, Stream stream)
{
new ElfBuilder().Save(context, stream);
}
private static bool TheSame(AsmContext prev, AsmContext current)
{
if (prev == null) return false;
return current.CodeSection.TheSame(prev.CodeSection);
}
private static void SkipEmptyLines(AsmContext context)
{
while (context.Queue.Count > 0) {
Token token = context.Queue.Peek();
if (token.Type != TokenType.NewLine) return;
context.Queue.Read();
}
}
private static void ProcessSection(AsmContext context)
{
var typeToken = context.Queue.Read();
if (typeToken.Type != TokenType.Literal) {
throw new TokenException("expected section type", typeToken);
}
var type = typeToken.ParseSectionType();
if (type == AsmSectionType.None) {
throw new TokenException("invalid section type", typeToken);
}
context.SetSection(type);
}
private static bool CheckLabel(Token token, AsmContext context)
{
if (context.Queue.Count > 0) {
var next = context.Queue.Peek();
if (next.Type == TokenType.Colon) {
context.Queue.Read();
context.DefineLabel(token);
return true;
}
}
return false;
}
private static bool CheckData(Token token, AsmContext context, AsmParser parser)
{
if (IsDataDirective(token)) {
ProcessDataDirective(token, parser, context.CurrentSection);
return true;
}
if (!context.Queue.IsEndOfLine) {
var preview = context.Queue.Peek();
if (IsDataDirective(preview)) {
context.Queue.Read(TokenType.Literal);
context.DefineLabel(token);
ProcessDataDirective(preview, parser, context.CurrentSection);
return true;
}
}
return false;
}
private static void AssemblePass(AsmContext context, AsmParser parser)
{
while (context.Queue.Count > 0) {
SkipEmptyLines(context);
if (context.Queue.Count == 0) break;
AssembleLine(context, parser);
}
}
private static void AssembleLine(AsmContext context, AsmParser parser)
{
var token = context.Queue.Read(TokenType.Literal);
try {
if (CheckLabel(token, context)) {
return;
}
if (CheckData(token, context, parser)) {
return;
}
switch (token.StringValue.ToLower()) {
case "section":
ProcessSection(context);
break;
case "org":
ProcessOrg(parser, context.CurrentSection);
break;
default:
var opcode = AvrOpcodes.Get(token.StringValue);
if (opcode != null) {
opcode.Compile(parser, context.CurrentSection);
} else {
throw new TokenException("Illegal instruction " + token.StringValue, token);
}
break;
}
if (context.Queue.Count > 0) {
var nl = context.Queue.Peek();
if (nl.Type != TokenType.NewLine) {
throw new TokenException("Extra characters on line", nl);
}
}
} catch (PureSectionDataException exc) {
throw new PureSectionDataException(exc.Message, token);
}
}
