path: root/include/elf.h

/**
** @file	elf.h
**
** @author	Warren R. Carithers
**
** @brief	ELF format declarations
*/

#ifndef ELF_H_
#define ELF_H_

#include <common.h>

#ifndef ASM_SRC

/*
** Start of C-only definitions
*/

// ELF data types (TIS ELF Spec v1.2, May 1995
typedef uint32_t e32_a; // 32-bit unsigned address
typedef uint16_t e32_h; // 16-bit unsigned "medium" integer
typedef uint32_t e32_o; // 32-bit unsigned offset
typedef int32_t e32_sw; // 32-bit signed "large" integer
typedef uint32_t e32_w; // 32-bit unsigned "large" integer
typedef uint8_t e32_si; // 8-bit unsigned "small" integer

// ELF magic number - first four bytes
#define ELF_MAGIC 0x464C457FU // "\x7FELF" in little-endian order
#define EI_NIDENT 16

union elfident_u {
	uint8_t bytes[EI_NIDENT]; // array of 16 bytes
	struct {
		uint32_t magic; // magic number
		uint8_t class; // file class
		uint8_t data; // data encoding
		uint8_t version; // file version
		uint8_t osabi; // OS ABI identification
		uint8_t abivers; // ABI version
		uint8_t pad[7]; // padding to 16 bytes
	} f;
};

// indices for byte fields in the ident array
#define EI_MAGIC 0
#define EI_MAG0 EI_MAGIC
#define EI_MAG1 1
#define EI_MAG2 2
#define EI_MAG3 3
#define EI_CLASS 4
#define EI_DATA 5
#define EI_VERSION 6
#define EI_OSABI 7
#define EI_ABIVERSION 8

// ELF classes
#define ELF_CLASS_NONE 0
#define ELF_CLASS_32 1 // 32-bit objects
#define ELF_CLASS_64 2 // 64-bit objects

// ELF data encoding
#define ELF_DATA_NONE 0 // invalid data encoding
#define ELF_DATA_2LSB 1 // two's complement little-endian
#define ELF_DATA_2MSB 2 // two's complement big-endian

// ELF versions
#define ELF_VERSION__NONE 0 // invalid version
#define EV_NONE ELF_VERSION_NONE
#define ELF_VERSION__CURRENT 1 // current version
#define EV_CURRENT ELF_VERSION_CURRENT

// ELF header
//
// field names are from the TIS ELF Spec v1.2, May 1995
typedef struct elfhdr_s {
	union elfident_u e_ident; // file identification
	e32_h e_type; // file type
	e32_h e_machine; // required architecture
	e32_w e_version; // object file version
	e32_a e_entry; // entry point (VA)
	e32_o e_phoff; // offset to program header table (PHT)
	e32_o e_shoff; // offset to section header table (SHT)
	e32_w e_flags; // processor-specific flags
	e32_h e_ehsize; // ELF header size (bytes)
	e32_h e_phentsize; // size of one PHT entry (bytes)
	e32_h e_phnum; // number of PHT entries
	e32_h e_shentsize; // size of one SHT entry (bytes)
	e32_h e_shnum; // number of SHT entries
	e32_h e_shstrndx; // SHT index of the sect. name string table
} elfhdr_t;

#define SZ_ELFHDR sizeof(elfhdr_t)

// field values
// e_type
#define ET_NONE 0 // no file type
#define ET_REL 1 // relocatable file
#define ET_EXEC 2 // executable file
#define ET_DYN 3 // shared object file
#define ET_CORE 4 // core file
#define ET_LO_OS 0xfe00 // processor-specific
#define ET_HI_OS 0xfeff // processor-specific
#define ET_LO_CP 0xff00 // processor-specific
#define ET_HI_CP 0xffff // processor-specific

// e_machine
#define EM_NONE 0x00 // no machine type
#define EM_M32 0x01 // AT&T WE 32100
#define EM_SPARC 0x02 // SUN SPARC
#define EM_386 0x03 // Intel Architecture
#define EM_68K 0x04 // Motorola 68000
#define EM_88K 0x05 // Motorola 88000
#define EM_IAMCU 0x06 // Intel MCU
#define EM_860 0x07 // Intel 80860
#define EM_MIPS 0x08 // MIPS RS3000 Big-Endian
#define EM_S370 0x09 // IBM System/370
#define EM_MIPS_RS3_LE 0x0a // MIPS RS3000 Big-Endian
#define EM_SPARC32PLLUS 0x12 // Sun "v8plus"
#define EM_PPC 0x14 // IBM PowerPC
#define EM_PPC64 0x15 // IBM PowerPC 64-bit
#define EM_S390 0x16 // IBM System/390
#define EM_ARM 0x28 // ARM up to V7/AArch32
#define EM_SPARCV9 0x2b // SPARC V9 64-bit
#define EM_IA_64 0x32 // Intel Itanium (Merced)
#define EM_MIPS_X 0x32 // Stanford MIPS-X
#define EM_X86_64 0x3E // AMD x86-64 (Intel64)
#define EM_PDP11 0x40 // DEC PDP-11
#define EM_VAX 0x4b // DEC VAX
#define EM_AARCH64 0xb7 // ARM AArch64
#define EM_Z80 0xec // Zilog Z-80
#define EM_AMDGPU 0xf0 // AMD GPU
#define EM_RISCV 0xf3 // RISC-V
#define EM_BPF 0xf7 // Berkeley Packet Filter

// ELF section header
//
// field names are from the TIS ELF Spec v1.2, May 1995
typedef struct shdr_s {
	e32_w sh_name; // section name (index into string table)
	e32_w sh_type; // section contents/semantics
	e32_w sh_flags; // attribute flag bits
	e32_a sh_addr; // 0, or load point of this section in memory
	e32_o sh_offset; // byte offset within the file
	e32_w sh_size; // section size in bytes
	e32_w sh_link; // section header index table link
	e32_w sh_info; // "extra information"
	e32_w sh_addralign; // required alignment
	e32_w sh_entsize; // 0, or size of each entry in the section
} elfsecthdr_t;

#define SZ_ELFSECTHDR sizeof(elfsecthdr_t)

// sh_name
#define SHN_UNDEF 0

// sh_type
#define SHT_NULL 0x00
#define SHT_PROGBITS 0x01
#define SHT_SYMTAB 0x02
#define SHT_STRTAB 0x03
#define SHT_RELA 0x04
#define SHT_HASH 0x05
#define SHT_DYNAMIC 0x06
#define SHT_NOTE 0x07
#define SHT_NOBITS 0x08
#define SHT_REL 0x09
#define SHT_SHLIB 0x0a
#define SHT_DYNSYM 0x0b
#define SHT_LO_CP 0x70000000
#define SHT_HI_CP 0x7fffffff
#define SHT_LO_US 0x80000000
#define SHT_HI_US 0x8fffffff

// sh_flags
#define SHF_WRITE 0x001
#define SHF_ALLOC 0x002
#define SHF_EXECINSTR 0x004
#define SHF_MERGE 0x010
#define SHF_STRINGS 0x020
#define SHF_INFO_LINK 0x040
#define SHF_LINK_ORDER 0x080
#define SHF_OS_NONCON 0x100
#define SHF_GROUP 0x200
#define SHF_TLS 0x400
#define SHF_MASKOS 0x0ff00000
#define SHF_MASKPROC 0xf0000000

// ELF program header
//
// field names are from the TIS ELF Spec v1.2, May 1995
typedef struct phdr_s {
	e32_w p_type; // type of segment
	e32_o p_offset; // byte offset in file
	e32_a p_va; // load point in memory (virtual address)
	e32_a p_pa; // load point in memory (physical address)
	e32_w p_filesz; // number of bytes in this file
	e32_w p_memsz; // number of bytes in memory
	e32_w p_flags; // attribute flag bits
	e32_w p_align; // required alignment
} elfproghdr_t;

#define SZ_ELFPROGHDR sizeof(elfproghdr_t)

// p_type
#define PT_NULL 0
#define PT_LOAD 1
#define PT_DYNAMIC 2
#define PT_INTERP 3
#define PT_NOTE 4
#define PT_SHLIB 5
#define PT_PHDR 6
#define PT_TLS 7
#define PT_LO_OS 0x70000000
#define PT_HI_OS 0x7fffffff
#define PT_LO_CP 0x70000000
#define PT_HI_CP 0x7fffffff

// p_flags
#define PF_E 0x1
#define PF_W 0x2
#define PF_R 0x4
#define PF_MASKPROC 0xf0000000

/*
** Globals
*/

/*
** Prototypes
*/

#endif /* !ASM_SRC */

#endif