// kernel.h
// Author: Josh Holtrop
// Date: 08/16/04
// This is the main kernel initialization and boot-strapping file

#include "kernel.h"
#include "multiboot.h"
#include "module.h"
#include "lang/asmfuncs.h"
#include "functions.h"
#include "mm/mm.h"
#include "mm/vmm.h"
#include "char/parallel.h"
#include "kout.h"
#include "lang/conv.h"
#include "char/vconsole.h"
#include "fs/devices.h"
#include "console.h"
#include "sys/io.h"
#include "sys/pic.h"

mb_info_t mb_info_block;
mb_mmap_t mb_mmap[MAX_MMAP];
u32_t mmap_entries;
mb_module_t mb_modules[MAX_MODULES];
mb_apm_t mb_apm_table;
byte real_mode_module;
char mb_cmdline[256];
int criticalCounter;	// semaphore for if interrupts are disabled
u32_t timer;

extern u32_t mm_freepages;

/* This function runs in segmented memory - 0xC000_0000 is mapped to 0x0 but 0x0
   itself is an invalid linear address. Therefore, the multiboot information addresses
   must be manually adjusted by VIRT_OFFSET to become valid linear addresses. */
int k_mbsave(mb_info_t *mbinfo, unsigned int mb_magic)
{
	real_mode_module = 0;
	if (mb_magic != MULTIBOOT_BOOTLOADER_MAGIC)
	{
		char *msg = "Bad multiboot magic identifier!";
		char *dest = (char *) CONSOLE_MEMORY;
		while (*msg)
		{
			*dest++ = *msg++;
			*dest++ = 0x04;		//red error message
		}
		for (;;) ;
	}
	mb_info_block = *mbinfo;
	if (mb_info_block.flags & MB_BOOTLOADER_COMMAND_LINE)
	{
		mb_info_block.cmdline += VIRT_OFFSET;
		memcpy(mb_cmdline, (void *)mb_info_block.cmdline, 256);
		mb_cmdline[255] = 0;
	}
	if (mb_info_block.flags & MB_BOOTLOADER_MODS)
	{
		mb_info_block.mods_addr += VIRT_OFFSET;
		int i;
		for (i = 0; i < mb_info_block.mods_count && i < MAX_MODULES; i++)
		{
			mb_modules[i] = ((mb_module_t *)mb_info_block.mods_addr)[i];
			mb_modules[i].mod_start += VIRT_OFFSET;
			mb_modules[i].mod_end += VIRT_OFFSET;
			hos_module_header_t *mod = (hos_module_header_t *)mb_modules[i].mod_start;
			if (mod->mod_type == MOD_REAL_MODE)
				real_mode_module = 1;
		}
	}
	if (mb_info_block.flags & MB_BOOTLOADER_MMAP)
	{
		mb_info_block.mmap_addr += (VIRT_OFFSET - 4);	//-4 to get to size field, not base_addr_low field
		mb_mmap_t *mmap = (mb_mmap_t *)mb_info_block.mmap_addr;
		int i, sz = 0;
		for (i = 0; sz < mb_info_block.mmap_length && i < MAX_MMAP; i++)
		{
			sz += mmap->size + 4;
			mb_mmap[i] = *mmap;
			mmap = (mb_mmap_t *)(((u32_t) mmap) + mmap->size + 4);
			mmap_entries++;
		}
	}
	if (mb_info_block.flags & MB_BOOTLOADER_APM)
	{
		mb_info_block.apm_table += VIRT_OFFSET;
		mb_apm_table = *(mb_apm_t *)mb_info_block.apm_table;
	}
	return real_mode_module;
}

/* Main kernel initialization routine */
void k_init()
{
	criticalCounter++;
	pic_remap(0x20, 0x28);
	pic_mask1(0);			//unmask IRQ's 0-7
	pic_mask2(0);			//unmask IRQ's 8-15
	timer_init(HOS_TIMER_FREQ);
	mm_init();
	vmm_init();
		// test the memory manager
/*	char *all;
	int size = 1;
	u32_t add = 1;
	for (;;)
	{
		all = kmalloc(size);
		add = (u32_t)all;
		if (!add)
			break;
		u32_t pte = (add >> 12) & 0x3FF;
		u32_t pde = add >> 22;
		u32_t mapped = *((u32_t *)(0xFFC00000 | (pde << 12) | (pte << 2)));
		kprintf("Got address 0x%x mapped to 0x%x size=%d\n", add, mapped, size);
		memset(all, 0, size);
		size <<= 1;
	}*/
	devices_init();
	console_init(6);
	console_activate(1);
	kprintf(" \e[31mWe \e[1mcan \e[32mfinally \e[33;45msee\e[0;7m text\e[0m!\n");
	u16_t *vidMem = (u16_t *)(CONSOLE_MEMORY + 160);
	u16_t i;
	for (i = 0; i < 256; i++)
	{
		*vidMem++ = (i << 8) | '*';
		if (((u32_t)vidMem % 32) == 0)
			vidMem += 64;
	}
	if (real_mode_module)
	{
		kprintf("Real mode module present\n");
	}
	criticalCounter--;
}

void isr(u32_t num)
{
	criticalCounter++;
	switch (num)
	{
	case 0x20:		// timer
		(*(u16_t *)CONSOLE_MEMORY)++;
		timer++;
		pic_eoi();
		break;
	case 0x21:		// keyboard
		isr_keyboard();
		pic_eoi();
		break;
	default:
		kprintf("Unhandled interrupt #%d, CR2 = 0x%x!\n", num, read_cr2());
		halt();
	}
	criticalCounter--;
}


void k_enter_critical()		// functions for implementing "atomic actions"
{
	disable_ints();
	criticalCounter++;
}

void k_leave_critical()
{
	criticalCounter--;
	if (!criticalCounter)
		enable_ints();
}