public override void DoCommand(binary_library.IBinaryFile output, IList<binary_library.IBinaryFile> inputs, LinkerScriptState state)
{
binary_library.ISymbol sym = output.CreateSymbol();
sym.Name = name;
sym.Type = binary_library.SymbolType.Global;
sym.DefinedIn = state.cur_section;
if (sym.DefinedIn == null)
{
output.AddSymbol(sym);
sym.Offset = state.cur_offset;
}
else
sym.Offset = state.cur_sect_offset;
}
public override void DoCommand(binary_library.IBinaryFile output, IList<binary_library.IBinaryFile> inputs, LinkerScriptState state)
{
// Generate a list of sections to include
IList<binary_library.ISection> sections = null;
Regex r = new Regex(WildcardToRegex(input_section));
switch (selection)
{
case InputFileSelection.All:
sections = new List<binary_library.ISection>();
foreach (binary_library.IBinaryFile ifile in inputs)
{
binary_library.ISection sect = ifile.FindSection(r);
if (sect != null)
sections.Add(sect);
}
break;
case InputFileSelection.AllNotSpecified:
sections = new List<binary_library.ISection>();
foreach (binary_library.IBinaryFile ifile in inputs)
{
binary_library.ISection sect = ifile.FindSection(r);
if ((sect != null) && (!state.included_sections.Contains(sect)))
sections.Add(sect);
}
break;
case InputFileSelection.Specific:
sections = new List<binary_library.ISection>();
foreach (binary_library.IBinaryFile ifile in inputs)
{
System.IO.FileInfo fi = new System.IO.FileInfo(ifile.Filename);
if (fi.Exists && (fi.Name == input_file))
{
binary_library.ISection sect = ifile.FindSection(r);
if ((sect != null) && (!state.included_sections.Contains(sect)))
sections.Add(sect);
}
}
break;
}
// Write the sections data to the section cache and its symbols to the output file
binary_library.ISection osect = state.cur_section;
foreach (binary_library.ISection sect in sections)
{
// Write the data
if (osect.HasData)
{
if (sect.HasData)
{
foreach (byte b in sect.Data)
state.data[osect].Add(b);
}
else
{
for (int i = 0; i < sect.Length; i++)
state.data[osect].Add(0);
}
}
else
osect.Length += sect.Length;
// Write the symbols
int sym_count = sect.GetSymbolCount();
for (int i = 0; i < sym_count; i++)
{
ISymbol sym = sect.GetSymbol(i);
ISymbol new_sym = output.CreateSymbol();
new_sym.Name = sym.Name;
new_sym.DefinedIn = osect;
new_sym.Offset = state.cur_sect_offset + sym.Offset;
new_sym.Size = sym.Size;
new_sym.Type = sym.Type;
new_sym.ObjectType = sym.ObjectType;
osect.AddSymbol(new_sym);
}
// Save where this section is loaded to
state.input_section_locations[sect] = new LinkerScriptState.InputSectionLocation { OutputSection = osect, OutputSectionOffset = state.cur_sect_offset };
state.cur_sect_offset += (ulong)sect.Length;
}
// Add the sections to the list of included sections
state.included_sections.AddRange(sections);
}
public void RunScript(binary_library.IBinaryFile output, IList<binary_library.IBinaryFile> inputs)
{
// First, identify the maximum sizes of common symbols
Dictionary<string, SizeAlign> comm_syms = new Dictionary<string, SizeAlign>();
foreach(var iput in inputs)
{
var comm = iput.GetCommonSection();
if(comm != null)
{
for(int i = 0; i < comm.GetSymbolCount(); i++)
{
var comm_sym = comm.GetSymbol(i);
if(comm_sym != null)
{
string name = comm_sym.Name;
if (comm_sym.Type == SymbolType.Local)
name = iput.Filename + "." + name;
if (!comm_syms.ContainsKey(name) ||
comm_syms[name].Size < comm_sym.Size)
comm_syms[name] = new SizeAlign { Size = (int)comm_sym.Size, Align = (int)comm_sym.Offset, Sym = comm_sym };
}
}
}
}
int comm_len = 0;
foreach (var k in comm_syms)
{
if ((comm_len % k.Value.Align) != 0)
comm_len = (comm_len / k.Value.Align) * k.Value.Align + k.Value.Align;
comm_len += k.Value.Size;
}
// Run the script
LinkerScriptState state = new LinkerScriptState();
state.comm_length = comm_len;
state.cur_section = output.GetGlobalSection();
foreach (ScriptEntry se in Script)
se.DoCommand(output, inputs, state);
// Resolve weak symbols
Dictionary<string, int> globl_syms = new Dictionary<string, int>();
int sym_idx = 0;
while(sym_idx < output.GetSymbolCount())
{
ISymbol sym = output.GetSymbol(sym_idx);
if(sym.Type == SymbolType.Weak)
{
// Whether to promote to a global symbol
bool for_removal = false;
// Have we found the appropriate global symbol before?
if (globl_syms.ContainsKey(sym.Name))
for_removal = true; // for removal
else
{
// Search from here onwards looking for a global
// symbol with the same name
for(int sym_idx_2 = sym_idx; sym_idx_2 < output.GetSymbolCount(); sym_idx_2++)
{
ISymbol sym_2 = output.GetSymbol(sym_idx_2);
if(sym_2.Type == SymbolType.Global &&
sym_2.Name == sym.Name)
{
globl_syms[sym.Name] = sym_idx_2;
for_removal = true;
break;
}
}
}
if(for_removal)
{
output.RemoveSymbol(sym_idx);
continue;
}
else
{
// Promote to a global symbol
sym.Type = SymbolType.Global;
globl_syms[sym.Name] = sym_idx;
}
}
else if (sym.Type == SymbolType.Global)
globl_syms[sym.Name] = sym_idx;
sym_idx++;
}
// Resolve common symbols. If a global symbol is defined for
// this, we use that, else we allocate a space in bss for it
ulong cur_comm_sym_offset = state.comm_offset;
foreach(var k in comm_syms.Keys)
{
if(!globl_syms.ContainsKey(k))
{
// define a symbol in the common section for this
if (state.comm_sect == null)
throw new Exception("Common sections used but no common section defined in linker script");
uint align = (uint)comm_syms[k].Align;
if ((cur_comm_sym_offset % align) != 0)
cur_comm_sym_offset = (cur_comm_sym_offset / align) * align + align;
ISymbol comm_sym = comm_syms[k].Sym;
//comm_sym.DefinedIn = state.comm_sect;
comm_sym.Offset = cur_comm_sym_offset;
comm_sym.Name = k;
cur_comm_sym_offset += (uint)comm_syms[k].Size;
}
}
// Now iterate through the data, saving to the appropriate sections
foreach (KeyValuePair<binary_library.ISection, List<byte>> kvp in state.data)
{
if (kvp.Key != null)
{
if (kvp.Key.HasData)
{
kvp.Key.Length = kvp.Value.Count;
for (int i = 0; i < kvp.Value.Count; i++)
kvp.Key.Data[i] = kvp.Value[i];
}
}
}
// Resolve relocations
foreach (IBinaryFile ifile in inputs)
{
int reloc_count = ifile.GetRelocationCount();
for (int i = 0; i < reloc_count; i++)
{
IRelocation reloc = ifile.GetRelocation(i);
// Is the location of the relocation included in the output?
if (state.included_sections.Contains(reloc.DefinedIn))
{
// Where is the value to be relocated?
LinkerScriptState.InputSectionLocation isl = state.input_section_locations[reloc.DefinedIn];
// Get the target of the relocation
ISymbol reloc_target = reloc.References;
ISection target_section = null;
ulong target_section_offset = 0;
if (reloc_target.DefinedIn == null)
{
// Try and find the requested symbol
ISymbol found_target = output.FindSymbol(reloc_target.Name);
if (found_target == null)
throw new Exception("Label '" + reloc_target.Name + "' not found");
target_section = found_target.DefinedIn;
target_section_offset = found_target.Offset;
}
else if(reloc_target.DefinedIn == reloc_target.DefinedIn.File.GetCommonSection())
{
// Get full name of symbol
string name = reloc_target.Name;
if (reloc_target.Type == SymbolType.Local)
name = reloc_target.DefinedIn.File.Filename + "." + name;
target_section = state.comm_sect;
if(globl_syms.ContainsKey(name))
{
ISymbol found_target = output.FindSymbol(reloc_target.Name);
if(found_target == null)
throw new Exception("Label '" + reloc_target.Name + "' not found");
target_section = found_target.DefinedIn;
target_section_offset = found_target.Offset;
}
else
{
target_section = state.comm_sect;
target_section_offset = reloc_target.Offset;
}
}
else
{
// Use the one stored in the relocation
// First find out where the input section is located in the output
if (!state.included_sections.Contains(reloc_target.DefinedIn))
throw new Exception();
LinkerScriptState.InputSectionLocation target_isl = state.input_section_locations[reloc_target.DefinedIn];
target_section = target_isl.OutputSection;
target_section_offset = target_isl.OutputSectionOffset + reloc_target.Offset;
}
// Create a new relocation for the output file
IRelocation new_reloc = output.CreateRelocation();
new_reloc.DefinedIn = isl.OutputSection;
new_reloc.Offset = isl.OutputSectionOffset + reloc.Offset;
new_reloc.Addend = reloc.Addend;
new_reloc.References = output.CreateSymbol();
new_reloc.References.DefinedIn = target_section;
new_reloc.References.Offset = target_section_offset;
new_reloc.References.Size = reloc_target.Size;
new_reloc.References.Name = reloc_target.Name;
new_reloc.Type = reloc.Type;
// Evaluate the relocation
long val = new_reloc.Type.Evaluate(new_reloc);
// Does it fit in the provided space?
bool fits = true;
ulong uval = BitConverter.ToUInt64(BitConverter.GetBytes(val), 0);
var t = new_reloc.Type;
ulong ext_mask = 0xffffffffffffffffUL << (t.BitLength + t.BitOffset);
if (new_reloc.Type.IsSigned)
{
var sign_bit = (uval >> (t.BitLength + t.BitOffset - 1)) & 0x1;
if (sign_bit == 1 && (uval & ext_mask) != ext_mask)
fits = false;
else if (sign_bit == 0 && (uval & ext_mask) != 0)
fits = false;
}
else if ((uval & ext_mask) != 0)
fits = false;
if (fits == false)
throw new Exception("Relocation truncated to fit: " +
reloc_target.Name + " against " +
t.Name);
// Build the new value to reinsert in the data stream
byte[] orig = new byte[8];
for (int idx = 0; idx < new_reloc.Type.Length; idx++)
orig[idx] = new_reloc.DefinedIn.Data[(int)new_reloc.Offset + idx];
ulong orig_val = BitConverter.ToUInt64(orig, 0);
// Mask out those bits we don't want
orig_val &= new_reloc.Type.KeepMask;
// Only set those bits we want
uval &= new_reloc.Type.SetMask;
uval |= orig_val;
byte[] uvalb = BitConverter.GetBytes(uval);
for (int idx = 0; idx < new_reloc.Type.Length; idx++)
new_reloc.DefinedIn.Data[(int)new_reloc.Offset + idx] = uvalb[idx];
}
}
}
// Remove local and undefined symbols from the output file
sym_idx = 0;
while(sym_idx < output.GetSymbolCount())
{
ISymbol sym = output.GetSymbol(sym_idx);
if (sym.Type == SymbolType.Local || sym.Type == SymbolType.Undefined)
output.RemoveSymbol(sym_idx);
else
sym_idx++;
}
// Mark the output as executable
output.IsExecutable = true;
}