/* ELF64 Object representation and parsing header. */

#include "cdef.h"
#include "proc.h"

typedef uint64 Elf64_Addr;
typedef uint64 Elf64_Off;
typedef uint16 Elf64_Half;
typedef uint32 Elf64_Word;
typedef uint32 Elf64_Sword;
typedef uint64 Elf64_Xword;
typedef uint64 Elf64_Sxword;
// This is custom
typedef uint8 uchar;


/* HEADER */

typedef struct
{
    uchar e_ident[16];
    Elf64_Half e_type;
    Elf64_Half e_machine;
    Elf64_Word e_version;
    Elf64_Addr e_entry;
    Elf64_Off e_phoff;
    Elf64_Off e_shoff;
    Elf64_Word e_flags;
    Elf64_Half e_ehsize;
    Elf64_Half e_phentsize;
    Elf64_Half e_phnum;
    Elf64_Half e_shentsize;
    Elf64_Half e_shnum;
    Elf64_Half e_shstrndx;
} elf64_hdr;

#define EI_MAG0 0 // should be \x7f
#define EI_MAG1 1 // E
#define EI_MAG2 2 // L
#define EI_MAG3 3 // F

#define ELFMAG0 '\x7f'
#define ELFMAG1 'E'
#define ELFMAG2 'L'
#define ELFMAG3 'F'

#define EI_CLASS 4
#define EI_DATA 5
#define EI_VERSION 6
#define EI_OSABI 7
#define EI_ABIVERSION 8
#define EI_PAD 9
#define EI_NIDENT 16

#define ELFCLASS32 1
#define ELFCLASS64 2

#define ELFDATA2LSB 1
#define ELFDATA2MSB 2

#define ELFOSABI_SYSV 0
#define ELFOSABI_HPUX 1
#define ELFOSABI_STANDALONE 255

#define ET_NONE 0
#define ET_REL 1
#define ET_EXEC 2
#define ET_DYN 3
#define ET_CORE 4

#define ET_LOOS 0xFE00
#define ET_HIOS 0XFEFF
#define ET_LOPROC 0XFF00
#define ET_HIPROC 0XFFFF

#define EV_CURRENT 1

typedef struct
{
    Elf64_Word	p_type;			/* Segment type */
    Elf64_Word	p_flags;		/* Segment flags */
    Elf64_Off	p_offset;		/* Segment file offset */
    Elf64_Addr	p_vaddr;		/* Segment virtual address */
    Elf64_Addr	p_paddr;		/* Segment physical address */
    Elf64_Xword	p_filesz;		/* Segment size in file */
    Elf64_Xword	p_memsz;		/* Segment size in memory */
    Elf64_Xword	p_align;		/* Segment alignment */
} elf64_phdr;

/* Special value for e_phnum.  This indicates that the real number of
   program headers is too large to fit into e_phnum.  Instead the real
   value is in the field sh_info of section 0.  */

#define PN_XNUM		0xffff

/* Legal values for p_type (segment type).  */

#define	PT_NULL		0		/* Program header table entry unused */
#define PT_LOAD		1		/* Loadable program segment */
#define PT_DYNAMIC	2		/* Dynamic linking information */
#define PT_INTERP	3		/* Program interpreter */
#define PT_NOTE		4		/* Auxiliary information */
#define PT_SHLIB	5		/* Reserved */
#define PT_PHDR		6		/* Entry for header table itself */
#define PT_TLS		7		/* Thread-local storage segment */
#define	PT_NUM		8		/* Number of defined types */
#define PT_LOOS		0x60000000	/* Start of OS-specific */
#define PT_GNU_EH_FRAME	0x6474e550	/* GCC .eh_frame_hdr segment */
#define PT_GNU_STACK	0x6474e551	/* Indicates stack executability */
#define PT_GNU_RELRO	0x6474e552	/* Read-only after relocation */
#define PT_LOSUNW	0x6ffffffa
#define PT_SUNWBSS	0x6ffffffa	/* Sun Specific segment */
#define PT_SUNWSTACK	0x6ffffffb	/* Stack segment */
#define PT_HISUNW	0x6fffffff
#define PT_HIOS		0x6fffffff	/* End of OS-specific */
#define PT_LOPROC	0x70000000	/* Start of processor-specific */
#define PT_HIPROC	0x7fffffff	/* End of processor-specific */

/* Legal values for p_flags (segment flags).  */

#define PF_X		(1 << 0)	/* Segment is executable */
#define PF_W		(1 << 1)	/* Segment is writable */
#define PF_R		(1 << 2)	/* Segment is readable */
#define PF_MASKOS	0x0ff00000	/* OS-specific */
#define PF_MASKPROC	0xf0000000	/* Processor-specific */


int32 elf_load_file(struct pcb *proc, void *file, void **entry);