//functions.h
//05/07/03 Josh Holtrop
//for HOS
//Modified: 02/26/04

#ifndef __HOS_FUNCTIONS__
#define __HOS_FUNCTIONS__ __HOS_FUNCTIONS__

#include "hos_defines.h"
#include "sys/io.h"

#ifdef __cplusplus
extern "C" {
#endif
extern u32_t _code;
extern u32_t _bss;
extern u32_t _end;
#ifdef __cplusplus
}
#endif

//Enables (SeTs) Interrupt Flag on the processor
static inline void enable_ints()
{
	asm("sti");
}

//Disables (CLears) Interrupt Flag on the processor
static inline void disable_ints()
{
	asm("cli");
}

//Restarts the computer
static inline void restart()
{
 	enable_ints();
 	byte temp;
	do
	{
		temp = inportb(0x64);
		if (temp & 1)
		inportb(0x60);
	} while(temp & 2);


	outportb (0x64, 0xfe);
	for (;;) {}
}

//Halts (freezes) the computer
static inline void halt()
{
 	asm("cli");
 	asm("hlt");
 	while (1) ;
}

//Initializes 8253 Programmable Interrupt Timer
static inline void timer_init(u32_t freq)
{
	u32_t	wait = 1193180 / freq;	//how many ticks the PIT must wait before issuing an interrupt
	outportb(0x43, 0x34);
	outportb(0x40, wait); //lsb
	outportb(0x40, wait >> 8); //msb
}

//Returns the size of the kernel (code & data & bss)
// - this should be 4kb aligned per the linker script
// - this is the amount of RAM the kernel code, data, & bss take
static inline u32_t kernel_size_used()
{
	return (u32_t)(&_end)-(u32_t)(&_code);
}

//Returns the size of the kernel (code & data)
// - this does not include the bss section
// - this should be 4kb aligned per the linker script
// - this should be the size of kernel.bin
static inline u32_t kernel_size()
{
	return (u32_t)(&_bss)-(u32_t)(&_code);
}

//converts a binary-coded-decimal byte to its decimal equivalent
static inline byte bcd2byte(byte bcd)
{
 	return (10 * ((bcd & 0xF0) >> 4)) + (bcd & 0x0F);
}

//converts a binary-coded-decimal byte to its decimal equivalent
static inline byte byte2bcd(byte bite)
{
	return ((bite / 10) << 4) | (bite % 10);
}

// get the maximum of two values
static inline u32_t max(u32_t v1, u32_t v2)
{
	return ( (v2 > v1) ? v2 : v1 );
}

// get the minimum of two values
static inline u32_t min(u32_t v1, u32_t v2)
{
	return ( (v2 > v1) ? v1 : v2 );
}

#endif