elf.h

//
// Created by leewy on 2016/10/27.
//

#ifndef RISCV_SIM_ELF_H
#define RISCV_SIM_ELF_H
using Elf_Char = unsigned char;
using Elf_Half = unsigned short;
using Elf_Word = unsigned int;
using Elf_Sword = unsigned long long;
struct elf_ident {
    Elf_Word EI_MAG;
    Elf_Char EI_CLASS;
    Elf_Char EI_DATA;
    Elf_Char EI_VERSION;
    Elf_Char EI_OSABI;
    Elf_Char EI_ABIVERSION;
    Elf_Char EI_PAD[7];  // unused
    elf_ident() = default;
    elf_ident(const char* elf_buffer);
};
// EI_MAG
const Elf_Word EIMAG = 0x464c457f;  // 0x7F followed by ELF(45 4c 46)
// EI_CLASS
const Elf_Char EICLASS_32 = 1;  // 32bit format
const Elf_Char EICLASS_64 = 2;  // 64bit format
// EI_DATA
const Elf_Char EIDATA_LITTLE = 1;  // little endianness
const Elf_Char EIDATA_BIG = 2;     // big endianness
// EI_VERSION
const Elf_Char EIVERSION = 1;  // Set to 1 for the original version of ELF.
// EI_OSABI
const Elf_Char EIABI_SYSV = 0;   // System V ABI
const Elf_Char EIABI_LINUX = 3;  // Linux ABI

struct elf32_header {
    elf_ident e_ident;     // Magic
    Elf_Half e_type;       // Type
    Elf_Half e_machine;    // Machine
    Elf_Word e_version;    // Version
    Elf_Word e_entry;      // Entry point address
    Elf_Word e_phoff;      // Start of program header
    Elf_Word e_shoff;      // Start of section header
    Elf_Word e_flag;       // Flags
    Elf_Half e_ehsize;     // Size of this header
    Elf_Half e_phentsize;  // Size of program headers
    Elf_Half e_phnum;      // Number of program headers
    Elf_Half e_shentsize;  // Size of section headers
    Elf_Half e_shunm;      // Number of section headers
    Elf_Half e_shstrndx;   // Section header string table index
    elf32_header() = default;
    elf32_header(const char* elf_buffer);
};

struct elf64_header {
    elf_ident e_ident;     // Magic
    Elf_Half e_type;       // Type
    Elf_Half e_machine;    // Machine
    Elf_Word e_version;    // Version
    Elf_Sword e_entry;     // Entry point address
    Elf_Sword e_phoff;     // Start of program header
    Elf_Sword e_shoff;     // Start of section header
    Elf_Word e_flag;       // Flags
    Elf_Half e_ehsize;     // Size of this header
    Elf_Half e_phentsize;  // Size of program headers
    Elf_Half e_phnum;      // Number of program headers
    Elf_Half e_shentsize;  // Size of section headers
    Elf_Half e_shnum;      // Number of section headers
    Elf_Half e_shstrndx;   // Section header string table index
    elf64_header() = default;
    elf64_header(const char* elf_buffer);
};

// e_type
const Elf_Half ET_NONE = 0;  // No file type
const Elf_Half ET_REL = 1;   // Relocatable file
const Elf_Half ET_EXEC = 2;  // Executable file
const Elf_Half ET_DYN = 3;   // Shared object file
const Elf_Half ET_CORE = 4;  // Core file

// e_machine
const Elf_Half EM_NONE = 0;       // No machine type
const Elf_Half EM_386 = 3;        // x86
const Elf_Half EM_x86_64 = 0x3e;  // x86_64
const Elf_Half EM_riscv = 0xf3;   // risc-v

// e_version
const Elf_Word EV_NODE = 0;     // Invalid version
const Elf_Word EV_CURRENT = 1;  // Current version

struct Elf32_Shdr {
    Elf_Word sh_name;
    Elf_Word sh_type;
    Elf_Word sh_flags;
    Elf_Word sh_addr;
    Elf_Word sh_offset;
    Elf_Word sh_size;
    Elf_Word sh_link;
    Elf_Word sh_info;
    Elf_Word sh_addralign;
    Elf_Word sh_entsize;
};
struct Elf64_Shdr {
    Elf_Word sh_name;
    Elf_Word sh_type;
    Elf_Sword sh_flags;
    Elf_Sword sh_addr;
    Elf_Sword sh_offset;
    Elf_Sword sh_size;
    Elf_Word sh_link;
    Elf_Word sh_info;
    Elf_Sword sh_addralign;
    Elf_Sword sh_entsize;
};
// sh_flags
const Elf_Word SHF_WRITE = 0x1;
const Elf_Word SHF_ALLOC = 0x2;
const Elf_Word SHF_EXECINSTR = 0x4;
const Elf_Word SHF_MERGE = 0x10;
const Elf_Word SHF_STRINGS = 0x20;
const Elf_Word SHF_INFO_LINK = 0x40;
const Elf_Word SHF_LINK_ORDER = 0x80;
const Elf_Word SHF_OS_NONCONFORMING = 0x100;
const Elf_Word SHF_GROUP = 0x200;
const Elf_Word SHF_MASKOS = 0x0ff00000;
const Elf_Word SHF_MASKPROC = 0xf0000000;
/*
 *  http://www.sco.com/developers/gabi/2000-07-17/ch4.sheader.html
Name	        Type	            Attributes
.bss	        SHT_NOBITS	        SHF_ALLOC+SHF_WRITE
.comment	    SHT_PROGBITS	    none
.data	        SHT_PROGBITS	    SHF_ALLOC+SHF_WRITE
.data1	        SHT_PROGBITS	    SHF_ALLOC+SHF_WRITE
.debug	        SHT_PROGBITS	    none
.dynamic	    SHT_DYNAMIC	        see below
.dynstr	        SHT_STRTAB	        SHF_ALLOC
.dynsym	        SHT_DYNSYM	        SHF_ALLOC
.fini	        SHT_PROGBITS	    SHF_ALLOC+SHF_EXECINSTR
.fini_array	    SHT_FINI_ARRAY	    SHF_ALLOC+SHF_WRITE
.got	        SHT_PROGBITS	    see below
.hash	        SHT_HASH	        SHF_ALLOC
.init	        SHT_PROGBITS	    SHF_ALLOC+SHF_EXECINSTR
.init_array	    SHT_INIT_ARRAY	    SHF_ALLOC+SHF_WRITE
.interp	        SHT_PROGBITS	    see below
.line	        SHT_PROGBITS	    none
.note	        SHT_NOTE	        none
.plt	        SHT_PROGBITS	    see below
.preinit_array	SHT_PREINIT_ARRAY	SHF_ALLOC+SHF_WRITE
.relname	    SHT_REL	            see below
.relaname	    SHT_RELA	        see below
.rodata	        SHT_PROGBITS	    SHF_ALLOC
.rodata1	    SHT_PROGBITS	    SHF_ALLOC
.shstrtab	    SHT_STRTAB	        none
.strtab	        SHT_STRTAB	        see below
.symtab	        SHT_SYMTAB	        see below
.symtab_shndx	SHT_SYMTAB_SHNDX    see below
.text	        SHT_PROGBITS	    SHF_ALLOC+SHF_EXECINSTR
*
 */

struct Elf32_Phdr {
    Elf_Word p_type;
    Elf_Word p_offset;
    Elf_Word p_vaddr;
    Elf_Word p_paddr;
    Elf_Word p_filesz;
    Elf_Word p_memsz;
    Elf_Word p_flags;
    Elf_Word p_align;
};

struct Elf64_Phdr {
    Elf_Word p_type;
    Elf_Word p_flags;
    Elf_Sword p_offset;
    Elf_Sword p_vaddr;
    Elf_Sword p_paddr;
    Elf_Sword p_filesz;
    Elf_Sword p_memsz;
    Elf_Sword p_align;
    Elf64_Phdr(const char* elf_buffer);
};
// p_type
const Elf_Word PT_LOAD = 1;

#endif  // RISCV_SIM_ELF_H