diff options
Diffstat (limited to 'src/ortho/mcode/binary_file-elf.adb')
| -rw-r--r-- | src/ortho/mcode/binary_file-elf.adb | 679 |
1 files changed, 679 insertions, 0 deletions
diff --git a/src/ortho/mcode/binary_file-elf.adb b/src/ortho/mcode/binary_file-elf.adb new file mode 100644 index 000000000..329dbacd3 --- /dev/null +++ b/src/ortho/mcode/binary_file-elf.adb @@ -0,0 +1,679 @@ +-- Binary file ELF writer. +-- Copyright (C) 2006 Tristan Gingold +-- +-- GHDL is free software; you can redistribute it and/or modify it under +-- the terms of the GNU General Public License as published by the Free +-- Software Foundation; either version 2, or (at your option) any later +-- version. +-- +-- GHDL is distributed in the hope that it will be useful, but WITHOUT ANY +-- WARRANTY; without even the implied warranty of MERCHANTABILITY or +-- FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +-- for more details. +-- +-- You should have received a copy of the GNU General Public License +-- along with GCC; see the file COPYING. If not, write to the Free +-- Software Foundation, 59 Temple Place - Suite 330, Boston, MA +-- 02111-1307, USA. +with Ada.Text_IO; use Ada.Text_IO; +with Ada.Characters.Latin_1; +with Elf_Common; +with Elf32; + +package body Binary_File.Elf is + NUL : Character renames Ada.Characters.Latin_1.NUL; + + type Arch_Bool is array (Arch_Kind) of Boolean; + Is_Rela : constant Arch_Bool := (Arch_Unknown => False, + Arch_X86 => False, + Arch_Sparc => True, + Arch_Ppc => True); + + procedure Write_Elf (Fd : GNAT.OS_Lib.File_Descriptor) + is + use Elf_Common; + use Elf32; + use GNAT.OS_Lib; + + procedure Xwrite (Data : System.Address; Len : Natural) is + begin + if Write (Fd, Data, Len) /= Len then + raise Write_Error; + end if; + end Xwrite; + + procedure Check_File_Pos (Off : Elf32_Off) + is + L : Long_Integer; + begin + L := File_Length (Fd); + if L /= Long_Integer (Off) then + Put_Line (Standard_Error, "check_file_pos error: expect " + & Elf32_Off'Image (Off) & ", found " + & Long_Integer'Image (L)); + raise Write_Error; + end if; + end Check_File_Pos; + + function Sect_Align (V : Elf32_Off) return Elf32_Off + is + Tmp : Elf32_Off; + begin + Tmp := V + 2 ** 2 - 1; + return Tmp - (Tmp mod 2 ** 2); + end Sect_Align; + + type Section_Info_Type is record + Sect : Section_Acc; + -- Index of the section symbol (in symtab). + Sym : Elf32_Word; + -- Number of relocs to write. + --Nbr_Relocs : Natural; + end record; + type Section_Info_Array is array (Natural range <>) of Section_Info_Type; + Sections : Section_Info_Array (0 .. 3 + 2 * Nbr_Sections); + type Elf32_Shdr_Array is array (Natural range <>) of Elf32_Shdr; + Shdr : Elf32_Shdr_Array (0 .. 3 + 2 * Nbr_Sections); + Nbr_Sect : Natural; + Sect : Section_Acc; + + -- The first 4 sections are always present. + Sect_Null : constant Natural := 0; + Sect_Shstrtab : constant Natural := 1; + Sect_Symtab : constant Natural := 2; + Sect_Strtab : constant Natural := 3; + Sect_First : constant Natural := 4; + + Offset : Elf32_Off; + + -- Size of a relocation entry. + Rel_Size : Natural; + + -- If true, do local relocs. + Flag_Reloc : constant Boolean := True; + -- If true, discard local symbols; + Flag_Discard_Local : Boolean := True; + + -- Number of symbols. + Nbr_Symbols : Natural := 0; + begin + -- If relocations are not performs, then local symbols cannot be + -- discarded. + if not Flag_Reloc then + Flag_Discard_Local := False; + end if; + + -- Set size of a relocation entry. This avoids severals conditionnal. + if Is_Rela (Arch) then + Rel_Size := Elf32_Rela_Size; + else + Rel_Size := Elf32_Rel_Size; + end if; + + -- Set section header. + + -- SHT_NULL. + Shdr (Sect_Null) := + Elf32_Shdr'(Sh_Name => 0, + Sh_Type => SHT_NULL, + Sh_Flags => 0, + Sh_Addr => 0, + Sh_Offset => 0, + Sh_Size => 0, + Sh_Link => 0, + Sh_Info => 0, + Sh_Addralign => 0, + Sh_Entsize => 0); + + -- shstrtab. + Shdr (Sect_Shstrtab) := + Elf32_Shdr'(Sh_Name => 1, + Sh_Type => SHT_STRTAB, + Sh_Flags => 0, + Sh_Addr => 0, + Sh_Offset => 0, -- Filled latter. + -- NUL: 1, .symtab: 8, .strtab: 8 and .shstrtab: 10. + Sh_Size => 1 + 10 + 8 + 8, + Sh_Link => 0, + Sh_Info => 0, + Sh_Addralign => 1, + Sh_Entsize => 0); + + -- Symtab + Shdr (Sect_Symtab) := + Elf32_Shdr'(Sh_Name => 11, + Sh_Type => SHT_SYMTAB, + Sh_Flags => 0, + Sh_Addr => 0, + Sh_Offset => 0, + Sh_Size => 0, + Sh_Link => Elf32_Word (Sect_Strtab), + Sh_Info => 0, -- FIXME + Sh_Addralign => 4, + Sh_Entsize => Elf32_Word (Elf32_Sym_Size)); + + -- strtab. + Shdr (Sect_Strtab) := + Elf32_Shdr'(Sh_Name => 19, + Sh_Type => SHT_STRTAB, + Sh_Flags => 0, + Sh_Addr => 0, + Sh_Offset => 0, + Sh_Size => 0, + Sh_Link => 0, + Sh_Info => 0, + Sh_Addralign => 1, + Sh_Entsize => 0); + + -- Fill sections. + Sect := Section_Chain; + Nbr_Sect := Sect_First; + Nbr_Symbols := 1; + while Sect /= null loop + Sections (Nbr_Sect) := (Sect => Sect, + Sym => Elf32_Word (Nbr_Symbols)); + Nbr_Symbols := Nbr_Symbols + 1; + Sect.Number := Nbr_Sect; + + Shdr (Nbr_Sect) := + Elf32_Shdr'(Sh_Name => Shdr (Sect_Shstrtab).Sh_Size, + Sh_Type => SHT_PROGBITS, + Sh_Flags => 0, + Sh_Addr => Elf32_Addr (Sect.Vaddr), + Sh_Offset => 0, + Sh_Size => 0, + Sh_Link => 0, + Sh_Info => 0, + Sh_Addralign => 2 ** Sect.Align, + Sh_Entsize => Elf32_Word (Sect.Esize)); + if Sect.Data = null then + Shdr (Nbr_Sect).Sh_Type := SHT_NOBITS; + end if; + if (Sect.Flags and Section_Read) /= 0 then + Shdr (Nbr_Sect).Sh_Flags := + Shdr (Nbr_Sect).Sh_Flags or SHF_ALLOC; + end if; + if (Sect.Flags and Section_Exec) /= 0 then + Shdr (Nbr_Sect).Sh_Flags := + Shdr (Nbr_Sect).Sh_Flags or SHF_EXECINSTR; + end if; + if (Sect.Flags and Section_Write) /= 0 then + Shdr (Nbr_Sect).Sh_Flags := + Shdr (Nbr_Sect).Sh_Flags or SHF_WRITE; + end if; + if Sect.Flags = Section_Strtab then + Shdr (Nbr_Sect).Sh_Type := SHT_STRTAB; + Shdr (Nbr_Sect).Sh_Addralign := 1; + Shdr (Nbr_Sect).Sh_Entsize := 0; + end if; + + Shdr (Sect_Shstrtab).Sh_Size := Shdr (Sect_Shstrtab).Sh_Size + + Sect.Name'Length + 1; -- 1 for Nul. + + Nbr_Sect := Nbr_Sect + 1; + if Flag_Reloc then + if Sect.First_Reloc /= null then + Do_Intra_Section_Reloc (Sect); + end if; + end if; + if Sect.First_Reloc /= null then + -- Add a section for the relocs. + Shdr (Nbr_Sect) := Elf32_Shdr' + (Sh_Name => Shdr (Sect_Shstrtab).Sh_Size, + Sh_Type => SHT_NULL, + Sh_Flags => 0, + Sh_Addr => 0, + Sh_Offset => 0, + Sh_Size => 0, + Sh_Link => Elf32_Word (Sect_Symtab), + Sh_Info => Elf32_Word (Nbr_Sect - 1), + Sh_Addralign => 4, + Sh_Entsize => Elf32_Word (Rel_Size)); + + if Is_Rela (Arch) then + Shdr (Nbr_Sect).Sh_Type := SHT_RELA; + else + Shdr (Nbr_Sect).Sh_Type := SHT_REL; + end if; + Shdr (Sect_Shstrtab).Sh_Size := Shdr (Sect_Shstrtab).Sh_Size + + Sect.Name'Length + 4 -- 4 for ".rel" + + Boolean'Pos (Is_Rela (Arch)) + 1; -- 1 for 'a', 1 for Nul. + + Nbr_Sect := Nbr_Sect + 1; + end if; + Sect := Sect.Next; + end loop; + + -- Lay-out sections. + Offset := Elf32_Off (Elf32_Ehdr_Size); + + -- Section table + Offset := Offset + Elf32_Off (Nbr_Sect * Elf32_Shdr_Size); + + -- shstrtab. + Shdr (Sect_Shstrtab).Sh_Offset := Offset; + + Offset := Sect_Align (Offset + Shdr (Sect_Shstrtab).Sh_Size); + + -- user-sections and relocation. + for I in Sect_First .. Nbr_Sect - 1 loop + Sect := Sections (I).Sect; + if Sect /= null then + Sect.Pc := Pow_Align (Sect.Pc, Sect.Align); + Shdr (Sect.Number).Sh_Size := Elf32_Word (Sect.Pc); + if Sect.Data /= null then + -- Set data offset. + Shdr (Sect.Number).Sh_Offset := Offset; + Offset := Offset + Shdr (Sect.Number).Sh_Size; + + -- Set relocs offset. + if Sect.First_Reloc /= null then + Shdr (Sect.Number + 1).Sh_Offset := Offset; + Shdr (Sect.Number + 1).Sh_Size := + Elf32_Word (Sect.Nbr_Relocs * Rel_Size); + Offset := Offset + Shdr (Sect.Number + 1).Sh_Size; + end if; + end if; + -- Set link. + if Sect.Link /= null then + Shdr (Sect.Number).Sh_Link := Elf32_Word (Sect.Link.Number); + end if; + end if; + end loop; + + -- Number symbols, put local before globals. + Nbr_Symbols := 1 + Nbr_Sections; + + -- First local symbols. + for I in Symbols.First .. Symbols.Last loop + case Get_Scope (I) is + when Sym_Private => + Set_Number (I, Nbr_Symbols); + Nbr_Symbols := Nbr_Symbols + 1; + when Sym_Local => + if not Flag_Discard_Local then + Set_Number (I, Nbr_Symbols); + Nbr_Symbols := Nbr_Symbols + 1; + end if; + when Sym_Undef + | Sym_Global => + null; + end case; + end loop; + + Shdr (Sect_Symtab).Sh_Info := Elf32_Word (Nbr_Symbols); + + -- Then globals. + for I in Symbols.First .. Symbols.Last loop + case Get_Scope (I) is + when Sym_Private + | Sym_Local => + null; + when Sym_Undef => + if Get_Used (I) then + Set_Number (I, Nbr_Symbols); + Nbr_Symbols := Nbr_Symbols + 1; + end if; + when Sym_Global => + Set_Number (I, Nbr_Symbols); + Nbr_Symbols := Nbr_Symbols + 1; + end case; + end loop; + + -- Symtab. + Shdr (Sect_Symtab).Sh_Offset := Offset; + -- 1 for nul. + Shdr (Sect_Symtab).Sh_Size := Elf32_Word (Nbr_Symbols * Elf32_Sym_Size); + + Offset := Offset + Shdr (Sect_Symtab).Sh_Size; + + -- Strtab offset. + Shdr (Sect_Strtab).Sh_Offset := Offset; + Shdr (Sect_Strtab).Sh_Size := 1; + + -- Compute length of strtab. + -- First, sections names. + Sect := Section_Chain; +-- while Sect /= null loop +-- Shdr (Sect_Strtab).Sh_Size := +-- Shdr (Sect_Strtab).Sh_Size + Sect.Name'Length + 1; +-- Sect := Sect.Prev; +-- end loop; + -- Then symbols. + declare + Len : Natural; + L : Natural; + begin + Len := 0; + for I in Symbols.First .. Symbols.Last loop + L := Get_Symbol_Name_Length (I) + 1; + case Get_Scope (I) is + when Sym_Local => + if Flag_Discard_Local then + L := 0; + end if; + when Sym_Private => + null; + when Sym_Global => + null; + when Sym_Undef => + if not Get_Used (I) then + L := 0; + end if; + end case; + Len := Len + L; + end loop; + + Shdr (Sect_Strtab).Sh_Size := + Shdr (Sect_Strtab).Sh_Size + Elf32_Word (Len); + end; + + -- Write file header. + declare + Ehdr : Elf32_Ehdr; + begin + Ehdr := (E_Ident => (EI_MAG0 => ELFMAG0, + EI_MAG1 => ELFMAG1, + EI_MAG2 => ELFMAG2, + EI_MAG3 => ELFMAG3, + EI_CLASS => ELFCLASS32, + EI_DATA => ELFDATANONE, + EI_VERSION => EV_CURRENT, + EI_PAD .. 15 => 0), + E_Type => ET_REL, + E_Machine => EM_NONE, + E_Version => Elf32_Word (EV_CURRENT), + E_Entry => 0, + E_Phoff => 0, + E_Shoff => Elf32_Off (Elf32_Ehdr_Size), + E_Flags => 0, + E_Ehsize => Elf32_Half (Elf32_Ehdr_Size), + E_Phentsize => 0, + E_Phnum => 0, + E_Shentsize => Elf32_Half (Elf32_Shdr_Size), + E_Shnum => Elf32_Half (Nbr_Sect), + E_Shstrndx => 1); + case Arch is + when Arch_X86 => + Ehdr.E_Ident (EI_DATA) := ELFDATA2LSB; + Ehdr.E_Machine := EM_386; + when Arch_Sparc => + Ehdr.E_Ident (EI_DATA) := ELFDATA2MSB; + Ehdr.E_Machine := EM_SPARC; + when others => + raise Program_Error; + end case; + Xwrite (Ehdr'Address, Elf32_Ehdr_Size); + end; + + -- Write shdr. + Xwrite (Shdr'Address, Nbr_Sect * Elf32_Shdr_Size); + + -- Write shstrtab + Check_File_Pos (Shdr (Sect_Shstrtab).Sh_Offset); + declare + Str : String := + NUL & ".shstrtab" & NUL & ".symtab" & NUL & ".strtab" & NUL; + Rela : String := NUL & ".rela"; + begin + Xwrite (Str'Address, Str'Length); + Sect := Section_Chain; + while Sect /= null loop + Xwrite (Sect.Name.all'Address, Sect.Name'Length); + if Sect.First_Reloc /= null then + if Is_Rela (Arch) then + Xwrite (Rela'Address, Rela'Length); + else + Xwrite (Rela'Address, Rela'Length - 1); + end if; + Xwrite (Sect.Name.all'Address, Sect.Name'Length); + end if; + Xwrite (NUL'Address, 1); + Sect := Sect.Next; + end loop; + end; + -- Pad. + declare + Delt : Elf32_Word; + Nul_Str : String (1 .. 4) := (others => NUL); + begin + Delt := Shdr (Sect_Shstrtab).Sh_Size and 3; + if Delt /= 0 then + Xwrite (Nul_Str'Address, Natural (4 - Delt)); + end if; + end; + + -- Write sections content and reloc. + for I in 1 .. Nbr_Sect loop + Sect := Sections (I).Sect; + if Sect /= null then + if Sect.Data /= null then + Check_File_Pos (Shdr (Sect.Number).Sh_Offset); + Xwrite (Sect.Data (0)'Address, Natural (Sect.Pc)); + end if; + declare + R : Reloc_Acc; + Rel : Elf32_Rel; + Rela : Elf32_Rela; + S : Elf32_Word; + Nbr_Reloc : Natural; + begin + R := Sect.First_Reloc; + Nbr_Reloc := 0; + while R /= null loop + if R.Done then + S := Sections (Get_Section (R.Sym).Number).Sym; + else + S := Elf32_Word (Get_Number (R.Sym)); + end if; + + if Is_Rela (Arch) then + case R.Kind is + when Reloc_Disp22 => + Rela.R_Info := Elf32_R_Info (S, R_SPARC_WDISP22); + when Reloc_Disp30 => + Rela.R_Info := Elf32_R_Info (S, R_SPARC_WDISP30); + when Reloc_Hi22 => + Rela.R_Info := Elf32_R_Info (S, R_SPARC_HI22); + when Reloc_Lo10 => + Rela.R_Info := Elf32_R_Info (S, R_SPARC_LO10); + when Reloc_32 => + Rela.R_Info := Elf32_R_Info (S, R_SPARC_32); + when Reloc_Ua_32 => + Rela.R_Info := Elf32_R_Info (S, R_SPARC_UA32); + when others => + raise Program_Error; + end case; + Rela.R_Addend := 0; + Rela.R_Offset := Elf32_Addr (R.Addr); + Xwrite (Rela'Address, Elf32_Rela_Size); + else + case R.Kind is + when Reloc_32 => + Rel.R_Info := Elf32_R_Info (S, R_386_32); + when Reloc_Pc32 => + Rel.R_Info := Elf32_R_Info (S, R_386_PC32); + when others => + raise Program_Error; + end case; + Rel.R_Offset := Elf32_Addr (R.Addr); + Xwrite (Rel'Address, Elf32_Rel_Size); + end if; + Nbr_Reloc := Nbr_Reloc + 1; + R := R.Sect_Next; + end loop; + if Nbr_Reloc /= Sect.Nbr_Relocs then + raise Program_Error; + end if; + end; + end if; + end loop; + + -- Write symbol table. + Check_File_Pos (Shdr (Sect_Symtab).Sh_Offset); + declare + Str_Off : Elf32_Word; + + procedure Gen_Sym (S : Symbol) + is + Sym : Elf32_Sym; + Bind : Elf32_Uchar; + Typ : Elf32_Uchar; + begin + Sym := Elf32_Sym'(St_Name => Str_Off, + St_Value => Elf32_Addr (Get_Symbol_Value (S)), + St_Size => 0, + St_Info => 0, + St_Other => 0, + St_Shndx => SHN_UNDEF); + if Get_Section (S) /= null then + Sym.St_Shndx := Elf32_Half (Get_Section (S).Number); + end if; + case Get_Scope (S) is + when Sym_Private + | Sym_Local => + Bind := STB_LOCAL; + Typ := STT_NOTYPE; + when Sym_Global => + Bind := STB_GLOBAL; + if Get_Section (S) /= null + and then (Get_Section (S).Flags and Section_Exec) /= 0 + then + Typ := STT_FUNC; + else + Typ := STT_OBJECT; + end if; + when Sym_Undef => + Bind := STB_GLOBAL; + Typ := STT_NOTYPE; + end case; + Sym.St_Info := Elf32_St_Info (Bind, Typ); + + Xwrite (Sym'Address, Elf32_Sym_Size); + + Str_Off := Str_Off + Elf32_Off (Get_Symbol_Name_Length (S) + 1); + end Gen_Sym; + + Sym : Elf32_Sym; + begin + + Str_Off := 1; + + -- write null entry + Sym := Elf32_Sym'(St_Name => 0, + St_Value => 0, + St_Size => 0, + St_Info => 0, + St_Other => 0, + St_Shndx => SHN_UNDEF); + Xwrite (Sym'Address, Elf32_Sym_Size); + + -- write section entries + Sect := Section_Chain; + while Sect /= null loop +-- Sym := Elf32_Sym'(St_Name => Str_Off, +-- St_Value => 0, +-- St_Size => 0, +-- St_Info => Elf32_St_Info (STB_LOCAL, +-- STT_NOTYPE), +-- St_Other => 0, +-- St_Shndx => Elf32_Half (Sect.Number)); +-- Xwrite (Sym'Address, Elf32_Sym_Size); +-- Str_Off := Str_Off + Sect.Name'Length + 1; + + Sym := Elf32_Sym'(St_Name => 0, + St_Value => 0, + St_Size => 0, + St_Info => Elf32_St_Info (STB_LOCAL, + STT_SECTION), + St_Other => 0, + St_Shndx => Elf32_Half (Sect.Number)); + Xwrite (Sym'Address, Elf32_Sym_Size); + Sect := Sect.Next; + end loop; + + -- First local symbols. + for I in Symbols.First .. Symbols.Last loop + case Get_Scope (I) is + when Sym_Private => + Gen_Sym (I); + when Sym_Local => + if not Flag_Discard_Local then + Gen_Sym (I); + end if; + when Sym_Global + | Sym_Undef => + null; + end case; + end loop; + + -- Then global symbols. + for I in Symbols.First .. Symbols.Last loop + case Get_Scope (I) is + when Sym_Global => + Gen_Sym (I); + when Sym_Undef => + if Get_Used (I) then + Gen_Sym (I); + end if; + when Sym_Private + | Sym_Local => + null; + end case; + end loop; + end; + + -- Write strtab. + Check_File_Pos (Shdr (Sect_Strtab).Sh_Offset); + -- First is NUL. + Xwrite (NUL'Address, 1); + -- Then the sections name. +-- Sect := Section_List; +-- while Sect /= null loop +-- Xwrite (Sect.Name.all'Address, Sect.Name'Length); +-- Xwrite (NUL'Address, 1); +-- Sect := Sect.Prev; +-- end loop; + + -- Then the symbols name. + declare + procedure Write_Sym_Name (S : Symbol) + is + Str : String := Get_Symbol_Name (S) & NUL; + begin + Xwrite (Str'Address, Str'Length); + end Write_Sym_Name; + begin + -- First locals. + for I in Symbols.First .. Symbols.Last loop + case Get_Scope (I) is + when Sym_Private => + Write_Sym_Name (I); + when Sym_Local => + if not Flag_Discard_Local then + Write_Sym_Name (I); + end if; + when Sym_Global + | Sym_Undef => + null; + end case; + end loop; + + -- Then global symbols. + for I in Symbols.First .. Symbols.Last loop + case Get_Scope (I) is + when Sym_Global => + Write_Sym_Name (I); + when Sym_Undef => + if Get_Used (I) then + Write_Sym_Name (I); + end if; + when Sym_Private + | Sym_Local => + null; + end case; + end loop; + end; + end Write_Elf; + +end Binary_File.Elf; |