/* 
 * Copyright 2010 Stefan Lankes, Chair for Operating Systems,
 *                               RWTH Aachen University
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * This file is part of MetalSVM.
 */

/**
 * @author Stefan Lankes
 * @file arch/x86/include/asm/multiboot.h
 * @brief Structures related to the Multiboot interface
 *
 * MetalSVM is able to use Multiboot (http://www.gnu.org/software/grub/manual/multiboot/),
 * which specifies an interface between a boot loader and a operating system.\n
 * \n
 * This file contains several structures needed to match the interface.
 */

#ifndef __ARCH_MULTIBOOT_H__
#define __ARCH_MULTIBOOT_H__

#include <metalsvm/stddef.h>

#ifdef CONFIG_MULTIBOOT

/// Does the bootloader provide mem_* fields?
#define MULTIBOOT_INFO_MEM		0x00000001
/// Does the bootloader provide a list of modules?
#define MULTIBOOT_INFO_MODS		0x00000008
/// Does the bootloader provide a full memory map?
#define MULTIBOOT_INFO_MEM_MAP		0x00000040

typedef uint16_t multiboot_uint16_t;
typedef uint32_t multiboot_uint32_t;
typedef uint64_t multiboot_uint64_t;

/** The symbol table for a.out. */
struct multiboot_aout_symbol_table
{
	multiboot_uint32_t tabsize;
	multiboot_uint32_t strsize;
	multiboot_uint32_t addr;
	multiboot_uint32_t reserved;
};
typedef struct multiboot_aout_symbol_table multiboot_aout_symbol_table_t;

/** The section header table for ELF. */
struct multiboot_elf_section_header_table
{
	multiboot_uint32_t num;
	multiboot_uint32_t size;
	multiboot_uint32_t addr;
	multiboot_uint32_t shndx;
};
typedef struct multiboot_elf_section_header_table multiboot_elf_section_header_table_t;

struct multiboot_info
{
	/** Multiboot info version number */
	multiboot_uint32_t flags;

	/** Available memory from BIOS */
	multiboot_uint32_t mem_lower;
	multiboot_uint32_t mem_upper;

	/** "root" partition */
	multiboot_uint32_t boot_device;

	/** Kernel command line */
	multiboot_uint32_t cmdline;

	/** Boot-Module list */
	multiboot_uint32_t mods_count;
	multiboot_uint32_t mods_addr;

	union
	{
		multiboot_aout_symbol_table_t aout_sym;
		multiboot_elf_section_header_table_t elf_sec;
	} u;

	/** Memory Mapping buffer */
	multiboot_uint32_t mmap_length;
	multiboot_uint32_t mmap_addr;

	/** Drive Info buffer */
	multiboot_uint32_t drives_length;
	multiboot_uint32_t drives_addr;

	/** ROM configuration table */
	multiboot_uint32_t config_table;

	/** Boot Loader Name */
	multiboot_uint32_t boot_loader_name;

	/** APM table */
	multiboot_uint32_t apm_table;

	/** Video */
	multiboot_uint32_t vbe_control_info;
	multiboot_uint32_t vbe_mode_info;
	multiboot_uint16_t vbe_mode;
	multiboot_uint16_t vbe_interface_seg;
	multiboot_uint16_t vbe_interface_off;
	multiboot_uint16_t vbe_interface_len;
};
typedef struct multiboot_info multiboot_info_t;

struct multiboot_mmap_entry
{
	multiboot_uint32_t size;
	multiboot_uint64_t addr;
	multiboot_uint64_t len;
#define MULTIBOOT_MEMORY_AVAILABLE 1
#define MULTIBOOT_MEMORY_RESERVED 2
	multiboot_uint32_t type;
} __attribute__((packed));
typedef struct multiboot_mmap_entry multiboot_memory_map_t;

struct multiboot_mod_list
{
	/** the memory used goes from bytes ’mod start’ to ’mod end-1’ inclusive */
	multiboot_uint32_t mod_start;
	multiboot_uint32_t mod_end;

	/** Module command line */
	multiboot_uint32_t cmdline;

	/** padding to take it to 16 bytes (must be zero) */
	multiboot_uint32_t pad;
};
typedef struct multiboot_mod_list multiboot_module_t;

extern multiboot_info_t*       mb_info;

#endif

#endif