rt-thread/src/module.h

#ifndef __MODULE_H__
#define __MODULE_H__

#include <rtdef.h>

typedef rt_uint8_t	Elf_Byte;

typedef rt_uint32_t	Elf32_Addr;	/* Unsigned program address */
typedef rt_uint32_t	Elf32_Off;	/* Unsigned file offset */
typedef rt_int32_t	Elf32_Sword;	/* Signed large integer */
typedef rt_uint32_t	Elf32_Word;	/* Unsigned large integer */
typedef rt_uint16_t	Elf32_Half;	/* Unsigned medium integer */

/* e_ident[] magic number */
#define	ELFMAG0		0x7f		/* e_ident[EI_MAG0] */
#define	ELFMAG1		'E'			/* e_ident[EI_MAG1] */
#define	ELFMAG2		'L'			/* e_ident[EI_MAG2] */
#define	ELFMAG3		'F'			/* e_ident[EI_MAG3] */
#define	ELFMAG		"\177ELF"	/* magic */
#define	SELFMAG		4			/* size of magic */

#define EI_CLASS	4		/* file class */
#define EI_NIDENT	16			/* Size of e_ident[] */

/* e_ident[] file class */
#define	ELFCLASSNONE	0		/* invalid */
#define	ELFCLASS32		1		/* 32-bit objs */
#define	ELFCLASS64		2		/* 64-bit objs */
#define	ELFCLASSNUM		3		/* number of classes */

/* e_ident[] data encoding */
#define ELFDATANONE		0		/* invalid */
#define ELFDATA2LSB		1		/* Little-Endian */
#define ELFDATA2MSB		2		/* Big-Endian */
#define ELFDATANUM		3		/* number of data encode defines */

/* e_ident */
#define IS_ELF(ehdr) ((ehdr).e_ident[EI_MAG0] == ELFMAG0 && \
                      (ehdr).e_ident[EI_MAG1] == ELFMAG1 && \
                      (ehdr).e_ident[EI_MAG2] == ELFMAG2 && \
                      (ehdr).e_ident[EI_MAG3] == ELFMAG3)

/* ELF Header */
typedef struct elfhdr {
	unsigned char	e_ident[EI_NIDENT]; /* ELF Identification */
	Elf32_Half	e_type;		/* object file type */
	Elf32_Half	e_machine;	/* machine */
	Elf32_Word	e_version;	/* object file version */
	Elf32_Addr	e_entry;	/* virtual entry point */
	Elf32_Off	e_phoff;	/* program header table offset */
	Elf32_Off	e_shoff;	/* section header table offset */
	Elf32_Word	e_flags;	/* processor-specific flags */
	Elf32_Half	e_ehsize;	/* ELF header size */
	Elf32_Half	e_phentsize;	/* program header entry size */
	Elf32_Half	e_phnum;	/* number of program header entries */
	Elf32_Half	e_shentsize;	/* section header entry size */
	Elf32_Half	e_shnum;	/* number of section header entries */
	Elf32_Half	e_shstrndx;	/* section header table's "section
					   header string table" entry offset */
} Elf32_Ehdr;

/* Section Header */
typedef struct {
	Elf32_Word	sh_name;	/* name - index into section header
					   string table section */
	Elf32_Word	sh_type;	/* type */
	Elf32_Word	sh_flags;	/* flags */
	Elf32_Addr	sh_addr;	/* address */
	Elf32_Off	sh_offset;	/* file offset */
	Elf32_Word	sh_size;	/* section size */
	Elf32_Word	sh_link;	/* section header table index link */
	Elf32_Word	sh_info;	/* extra information */
	Elf32_Word	sh_addralign;	/* address alignment */
	Elf32_Word	sh_entsize;	/* section entry size */
} Elf32_Shdr;

/* Section names */
#define ELF_BSS         ".bss"		/* uninitialized data */
#define ELF_DATA        ".data"		/* initialized data */
#define ELF_DEBUG       ".debug"	/* debug */
#define ELF_DYNAMIC     ".dynamic"	/* dynamic linking information */
#define ELF_DYNSTR      ".dynstr"	/* dynamic string table */
#define ELF_DYNSYM      ".dynsym"	/* dynamic symbol table */
#define ELF_FINI        ".fini"		/* termination code */
#define ELF_GOT         ".got"		/* global offset table */
#define ELF_HASH        ".hash"		/* symbol hash table */
#define ELF_INIT        ".init"		/* initialization code */
#define ELF_REL_DATA    ".rel.data"	/* relocation data */
#define ELF_REL_FINI    ".rel.fini"	/* relocation termination code */
#define ELF_REL_INIT    ".rel.init"	/* relocation initialization code */
#define ELF_REL_DYN     ".rel.dyn"	/* relocaltion dynamic link info */
#define ELF_REL_RODATA  ".rel.rodata"	/* relocation read-only data */
#define ELF_REL_TEXT    ".rel.text"	/* relocation code */
#define ELF_RODATA      ".rodata"	/* read-only data */
#define ELF_SHSTRTAB    ".shstrtab"	/* section header string table */
#define ELF_STRTAB      ".strtab"	/* string table */
#define ELF_SYMTAB      ".symtab"	/* symbol table */
#define ELF_TEXT        ".text"		/* code */

/* Symbol Table Entry */
typedef struct elf32_sym {
	Elf32_Word	st_name;	/* name - index into string table */
	Elf32_Addr	st_value;	/* symbol value */
	Elf32_Word	st_size;	/* symbol size */
	unsigned char	st_info;	/* type and binding */
	unsigned char	st_other;	/* 0 - no defined meaning */
	Elf32_Half	st_shndx;	/* section header index */
} Elf32_Sym;

#define	STB_LOCAL	0		/* BIND */
#define	STB_GLOBAL	1
#define	STB_WEAK	2
#define	STB_NUM	3
 
#define	STB_LOPROC	13		/* processor specific range */
#define	STB_HIPROC	15

#define	STT_NOTYPE	0		/* symbol type is unspecified */
#define	STT_OBJECT	1		/* data object */
#define	STT_FUNC	2		/* code object */
#define	STT_SECTION	3	/* symbol identifies an ELF section */
#define	STT_FILE	4		/* symbol's name is file name */
#define	STT_COMMON	5	/* common data object */
#define	STT_TLS		6		/* thread-local data object */
#define	STT_NUM	7		/* # defined types in generic range */
#define	STT_LOOS	10		/* OS specific range */
#define	STT_HIOS	12
#define	STT_LOPROC	13		/* processor specific range */
#define	STT_HIPROC	15
    

#define	ELF_ST_BIND(info)			((info) >> 4)
#define	ELF_ST_TYPE(info)			((info) & 0xf)
#define	ELF_ST_INFO(bind, type)		(((bind)<<4)+((type)&0xf))	

/* Relocation entry with implicit addend */
typedef struct {
	Elf32_Addr	r_offset;	/* offset of relocation */
	Elf32_Word	r_info;		/* symbol table index and type */
} Elf32_Rel;

/* Relocation entry with explicit addend */
typedef struct {
	Elf32_Addr	r_offset;	/* offset of relocation */
	Elf32_Word	r_info;		/* symbol table index and type */
	Elf32_Sword	r_addend;
} Elf32_Rela;

/* Extract relocation info - r_info */
#define ELF32_R_SYM(i)		((i) >> 8)
#define ELF32_R_TYPE(i)		((unsigned char) (i))
#define ELF32_R_INFO(s,t) 	(((s) << 8) + (unsigned char)(t))

/*
 * Relocation type for arm
 */
#define	R_ARM_NONE	0
#define	R_ARM_PC24	1
#define	R_ARM_ABS32	2
#define	R_ARM_PLT32	27
#define	R_ARM_CALL	28
#define R_ARM_JUMP24	29

/* Program Header */
typedef struct {
	Elf32_Word	p_type;		/* segment type */
	Elf32_Off	p_offset;	/* segment offset */
	Elf32_Addr	p_vaddr;	/* virtual address of segment */
	Elf32_Addr	p_paddr;	/* physical address - ignored? */
	Elf32_Word	p_filesz;	/* number of bytes in file for seg. */
	Elf32_Word	p_memsz;	/* number of bytes in mem. for seg. */
	Elf32_Word	p_flags;	/* flags */
	Elf32_Word	p_align;	/* memory alignment */
} Elf32_Phdr;

/* sh_type */
#define SHT_NULL	0		/* inactive */
#define SHT_PROGBITS	1		/* program defined information */
#define SHT_SYMTAB	2		/* symbol table section */
#define SHT_STRTAB	3		/* string table section */
#define SHT_RELA	4		/* relocation section with addends*/
#define SHT_HASH	5		/* symbol hash table section */
#define SHT_DYNAMIC	6		/* dynamic section */
#define SHT_NOTE	7		/* note section */
#define SHT_NOBITS	8		/* no space section */
#define SHT_REL		9		/* relation section without addends */
#define SHT_SHLIB	10		/* reserved - purpose unknown */
#define SHT_DYNSYM	11		/* dynamic symbol table section */
#define SHT_NUM		12		/* number of section types */
#define SHT_LOPROC	0x70000000	/* reserved range for processor */
#define SHT_HIPROC	0x7fffffff	/*  specific section header types */
#define SHT_LOUSER	0x80000000	/* reserved range for application */
#define SHT_HIUSER	0xffffffff	/*  specific indexes */

/* Section Attribute Flags - sh_flags */
#define SHF_WRITE	0x1		/* Writable */
#define SHF_ALLOC	0x2		/* occupies memory */
#define SHF_EXECINSTR	0x4		/* executable */
#define SHF_MASKPROC	0xf0000000	/* reserved bits for processor */
					/*  specific section attributes */

/* Symbol table index */
#define STN_UNDEF	0		/* undefined */

#endif