/*******************************************************************************

    Copyright(C) Jonas 'Sortie' Termansen 2011.

    This file is part of Sortix.

    Sortix 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 3 of the License, or (at your option) any later
    version.

    Sortix 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
    Sortix. If not, see <http://www.gnu.org/licenses/>.

    elf.h
    Constructs processes from ELF files.

*******************************************************************************/

#ifndef SORTIX_ELF_H
#define SORTIX_ELF_H

namespace Sortix
{
	class Process;

	namespace ELF
	{
		struct Header
		{
			unsigned char magic[4];
			unsigned char fileclass;
			unsigned char dataencoding;
			unsigned char version;
			unsigned char osabi;
			unsigned char abiversion;
			unsigned char padding[7];
		};

		const unsigned char CLASSNONE = 0;
		const unsigned char CLASS32 = 1;
		const unsigned char CLASS64 = 2;
		const unsigned char DATA2LSB = 1;
		const unsigned char DATA2MSB = 2;
		const unsigned char CURRENTVERSION = 1;

		struct Header32 : public Header
		{
			uint16_t type;
			uint16_t machine;
			uint32_t version;
			uint32_t entry;
			uint32_t programheaderoffset;
			uint32_t sectionheaderoffset;
			uint32_t flags;
			uint16_t elfheadersize;
			uint16_t programheaderentrysize;
			uint16_t numprogramheaderentries;
			uint16_t sectionheaderentrysize;
			uint16_t numsectionheaderentries;
			uint16_t sectionheaderstringindex;
		};

		struct Header64 : public Header
		{
			uint16_t type;
			uint16_t machine;
			uint32_t version;
			uint64_t entry;
			uint64_t programheaderoffset;
			uint64_t sectionheaderoffset;
			uint32_t flags;
			uint16_t elfheadersize;
			uint16_t programheaderentrysize;
			uint16_t numprogramheaderentries;
			uint16_t sectionheaderentrysize;
			uint16_t numsectionheaderentries;
			uint16_t sectionheaderstringindex;
		};

		struct SectionHeader32
		{
			uint32_t name;
			uint32_t type;
			uint32_t flags;
			uint32_t addr;
			uint32_t offset;
			uint32_t size;
			uint32_t link;
			uint32_t info;
			uint32_t addralign;
			uint32_t entsize;
		};

		struct SectionHeader64
		{
			uint32_t name;
			uint32_t type;
			uint64_t flags;
			uint64_t addr;
			uint64_t offset;
			uint64_t size;
			uint32_t link;
			uint32_t info;
			uint64_t addralign;
			uint64_t entsize;
		};

		const uint32_t SHT_NULL = 0;
		const uint32_t SHT_PROGBITS = 1;
		const uint32_t SHT_SYMTAB = 2;
		const uint32_t SHT_STRTAB = 3;
		const uint32_t SHT_RELA = 4;
		const uint32_t SHT_HASH = 5;
		const uint32_t SHT_DYNAMIC = 6;
		const uint32_t SHT_NOTE = 7;
		const uint32_t SHT_NOBITS = 8;
		const uint32_t SHT_REL = 9;
		const uint32_t SHT_SHLIB = 10;
		const uint32_t SHT_DYNSYM = 11;
		const uint32_t SHT_LOPROC = 0x70000000;
		const uint32_t SHT_HIPROC = 0x7fffffff;
		const uint32_t SHT_LOUSER = 0x80000000;
		const uint32_t SHT_HIUSER = 0xffffffff;

		struct ProgramHeader32
		{
			uint32_t type;
			uint32_t offset;
			uint32_t virtualaddr;
			uint32_t physicaladdr;
			uint32_t filesize;
			uint32_t memorysize;
			uint32_t flags;
			uint32_t align;
		};

		struct ProgramHeader64
		{
			uint32_t type;
			uint32_t flags;
			uint64_t offset;
			uint64_t virtualaddr;
			uint64_t physicaladdr;
			uint64_t filesize;
			uint64_t memorysize;
			uint64_t align;
		};

		const uint32_t PT_NULL = 0;
		const uint32_t PT_LOAD = 1;
		const uint32_t PT_DYNAMIC = 2;
		const uint32_t PT_INTERP = 3;
		const uint32_t PT_NOTE = 4;
		const uint32_t PT_SHLIB = 5;
		const uint32_t PT_PHDR = 6;
		const uint32_t PT_LOPROC = 0x70000000;
		const uint32_t PT_HIPROC = 0x7FFFFFFF;

		const uint32_t PF_X = (1<<0);
		const uint32_t PF_W = (1<<1);
		const uint32_t PF_R = (1<<2);

		// Reads the elf file into the current address space and returns the
		// entry address of the program, or 0 upon failure.
		addr_t Construct(Process* process, const void* file, size_t filelen);
	}
}

#endif