/*
    Copyright (C) 2012, Aaron Lindsay <aaron@aclindsay.com>

    This file is part of Aedrix.

    This program 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 2 of the License, or
    (at your option) any later version.

    This program 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 this program; if not, write to the Free Software Foundation, Inc.,
    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <arch/multiboot.h>
#include <mmu.h>

struct multiboot_mmap {
	unsigned int size;
	unsigned int base_addr_low, base_addr_high;
	unsigned int length_low, length_high;
	unsigned int type;
};

extern multiboot_info_t* multiboot_mbd;
extern uint32 multiboot_magic;

int detect_memory_mmap() {
	struct multiboot_mmap* mmap = (struct multiboot_mmap*)multiboot_mbd->mmap_addr;
	int found_region = 0;

	while ((char*)mmap < (char*)multiboot_mbd->mmap_addr + multiboot_mbd->mmap_length) {
		if (mmap->base_addr_high || mmap->length_high)
			return -1;
		if (mmap->type == 0x1) { /* ignore non-usable memory */
			declare_memory_region((void*)mmap->base_addr_low,
				(void*)(mmap->base_addr_low + mmap->length_low));
			found_region = 1;
		}
		mmap = (struct multiboot_mmap*) ((unsigned int)mmap + mmap->size + sizeof(unsigned int));
	}

	return !found_region;
}

int detect_memory_contiguous() {
	declare_memory_region((void*)0x0, (void*)((uint32)multiboot_mbd->mem_lower * 1024));
	declare_memory_region((void*)0x1000000, (void*)((uint32)multiboot_mbd->mem_upper*1024 + 0x100000));
	return 0;
}

int detect_memory() {
	if (multiboot_mbd->flags & (1<<6))
		return detect_memory_mmap();
	else if (multiboot_mbd->flags & (1<<0))
		return detect_memory_contiguous();
	return -1;
}