#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "libsys.h"

UINT8 g_pattern8[] = {0x01, 0x02, 0x03, 0x4, 0x05, 0x06, 0x07, 0x08};
UINT16 g_pattern16[sizeof(g_pattern8)/2] = {0};
UINT32 g_pattern32[sizeof(g_pattern8)/4] = {0};
UINT8 _g_bytes[4] = {0x12, 0x34, 0x56, 0x78};
UINT8 _g_bytes2[4] = {0};

void MakePattern(void)
{

	int i;

	UINT16 *pPat16 = (UINT16*)g_pattern8;
	UINT32 *pPat32 = (UINT32*)g_pattern8;


	for (i=0; i < sizeof(g_pattern16)/2; i++)
	{
		g_pattern16[i] =  pPat16[i];
	}

	for (i=0; i < sizeof(g_pattern32)/4; i++)
	{
		g_pattern32[i] =  pPat32[i];
	}
}

void PrintPattern(void)
{

	int i;

	printf("Pattern 8bit:\n");
	for (i=0; i < sizeof(g_pattern8); i++)
	{
		printf("%02X ", g_pattern8[i]);
	}
	printf("\n");

	printf("Pattern 16bit:\n");
	for (i=0; i < sizeof(g_pattern16)/2; i++)
	{
		printf("%04X ", g_pattern16[i]);
	}
	printf("\n");

	printf("Pattern 32bit:\n");
	for (i=0; i < sizeof(g_pattern32)/4; i++)
	{
		printf("%08X ", g_pattern32[i]);
	}
	printf("\n");
}

int IsEndianBig(void)
{
	int i, result;

	UINT8 *pBuf8;
	UINT16 *pBuf16;
	UINT32 *pBuf32;
	UINT16 halve;
	UINT32 word;


	halve = 0x1234;
	word = 0x12345678;

	result = -1;

	for (i=0; i < 4; i++)
		_g_bytes2[i] = _g_bytes[i];

	pBuf8 = (UINT8*)&word;
	if (((*pBuf8+0) == 0x12) && (*(pBuf8+1) == 0x34) && (*(pBuf8+2) == 0x56) && (*(pBuf8+3) == 0x78))
	{
		pBuf8 = (UINT8*)&halve;
		if (((*pBuf8+0) == 0x12) && (*(pBuf8+1) == 0x34))
		{
			result = 1;
		}
	}

	pBuf8 = (UINT8*)&word;
	if (((*pBuf8+0) == 0x78) && (*(pBuf8+1) == 0x56) && (*(pBuf8+2) == 0x34) && (*(pBuf8+3) == 0x12))
	{
		pBuf8 = (UINT8*)&halve;
		if (((*pBuf8+0) == 0x34) && (*(pBuf8+1) == 0x12))
		{
			result = 0;
		}
	}
	return result;
}

void PrintCPUinfo(void)
{
	int result, rev_id;
	int cache_size, cache_line;
	int eb;

	char *cpu_type_str[7] = {"invalid", "R2000", "R3000", "R6000", "R4000", "reserved", "R6000A"};

	// Print Status register
	result = CP0_SR_read();

	printf("--------------------------------------------------\n");
	printf("Status   : %8.8X\n", result);

	// Print Revision
	result = CP0_PRID_read();
	rev_id = (result >> 8) & 0xFF;
	printf("CPU type : MIPS ");
	if ((rev_id > 0) && (rev_id < 0x07))
	{
		printf(cpu_type_str[rev_id]);
		printf(" Rev. ");
		rev_id = result & 0xFF;
		printf("%d", rev_id);
	}
	else
		printf("Unknown");

	eb = IsEndianBig();
	if (eb > 0)
		printf(" [Big-endian]\n");
	if (eb == 0)
		printf(" [Little-endian]\n");
	if (eb < 0)
		printf(" [Unknown endian]\n");

	printf("--------------------------------------------------\n");

}

int main (void)
{
	int eb;

	setbuf(stdout, NULL);
	CP0_SR_write(CP0_SR_read() & ~(1 << 25));

	PrintCPUinfo();

	if (IsEndianBig() == 1)
		printf("Endian is big\n");
	if (IsEndianBig() == 0)
		printf("Endian is little\n");

	PrintBuffer8(_g_bytes2, 8, 4);
	MakePattern();
	PrintPattern();

	memset(g_pattern16, 0, sizeof(g_pattern16));
	memset(g_pattern32, 0, sizeof(g_pattern32));

	CP0_SR_write(CP0_SR_read() | (1 << 25));
	eb = IsEndianBig();

	MakePattern();

	CP0_SR_write(CP0_SR_read() & ~(1 << 25));
	if (eb == 1)
		printf("Endian is big\n");
	if (eb == 0)
		printf("Endian is little\n");
	PrintBuffer8(_g_bytes2, 8, 4);

	PrintPattern();

	return 0;
}