#include <stdint.h>

#include <stdio.h>

#include <kernel/paging.h>

//extern uint32_t endkernel; // found in link.ld

/**
 * The page table must be page aligned (aligned at 4KiB)
 *
 *
 * This is a temporary solution, as we want a page frame allocator, to properly get page frames.. but this works for now
 */
uint32_t page_directory[PAGE_DIRECTORY_ENTRIES] __attribute__((aligned(4096)));

uint32_t first_page_table[PAGE_TABLE_ENTRIES] __attribute__((aligned(4096)));

void setup_page_table(void)
{
	uint32_t i;
	for (i = 0; i < PAGE_TABLE_ENTRIES; i++) {
		first_page_table[i] = (i * 0x1000) | 3; // supervisor, r/w, present
	}
	puts("test");
}

void setup_page_dir(void)
{
	setup_page_table();
	/**
	 * Now that we have a page directory, we need to blank it.
	 *
	 * The page directory should have exactly 1024 entries. We will set each entry to not present, so that the if the
	 * MMU looks for that page table, it will see that it is not there yet.
	 */
	int i;
	for (i = 0; i < PAGE_DIRECTORY_ENTRIES; i++) {
		// This sets the following flags to the pages:
		// 	Supervisor: Only kernel-mode can access them
		// 	Write Enabled: It can be both read from and written to
		// 	Not Present: The page table is not present
		page_directory[i] = 0x00000002;
	}

	page_directory[0] = ((uint32_t) first_page_table) | 3;
}

void setup_paging(void)
{
	setup_page_dir();

	load_page_directory(page_directory);
	enable_paging();
}