#define WIN32_LEAN_AND_MEAN
#define WIN32_EXTRA_LEAN
#include <windows.h>
#include <stdlib.h>
#include <stdio.h>
#include <malloc.h>

HANDLE hFile;
HANDLE hMap;
HANDLE hOut;
LPBYTE pIn;
LPBYTE pRom;
DWORD  dwSizeLo, dwSizeHi;
BYTE   szVersion[16];
BOOL   bUnpack = FALSE;
BOOL   bSwap = FALSE;
BOOL   bText = FALSE;
DWORD  dwWritten;
WORD   wCRC;
BOOL   bIsGx;

static WORD crc_table[16] =
{
	0x0000, 0x1081, 0x2102, 0x3183, 0x4204, 0x5285, 0x6306, 0x7387,
	0x8408, 0x9489, 0xA50A, 0xB58B, 0xC60C, 0xD68D, 0xE70E, 0xF78F
};
static __inline VOID CRC(BYTE nib)
{
	wCRC = (WORD)((wCRC>>4)^crc_table[(wCRC^nib)&0xf]);
}

BOOL CheckCRC()
{
	DWORD dwD0, dwD1;
	WORD  wRomCRC;
	UINT  i;
	DWORD dwBase = 0x00000;
	UINT  nPass = 0;
	UINT  nPasses = bIsGx?2:1;

again:

	wRomCRC = pRom[dwBase+0x7FFFC]
			|(pRom[dwBase+0x7FFFD]<<4)
			|(pRom[dwBase+0x7FFFE]<<8)
			|(pRom[dwBase+0x7FFFF]<<12);

	wCRC = 0x0000;
	dwD0 = dwBase + 0x00000;
	dwD1 = dwBase + 0x40000;
	do
	{
		for (i=0; i<16; i++) CRC(pRom[dwD0+i]);
		for (i=0; i<16; i++) CRC(pRom[dwD1+i]);
		dwD0 += 16;
		dwD1 += 16;
	} while (dwD0&0x3FFFF);

	if (wCRC==0xFFFF)
	{
		printf("CRC%i: %04X Ok\n", nPass, wRomCRC);
	}
	else
	{
		printf("CRC%i: %04X Failed (%04X)\n", nPass, wRomCRC, wCRC);
		return FALSE;
	}

	if (++nPass == nPasses) return TRUE;

	dwBase += 0x80000;
	goto again;

}

static BYTE Asc2Nib(char c)
{
	if (c<'0') return 0;
	if (c<='9') return c-'0';
	if (c<'A') return 0;
	if (c<='F') return c-'A'+10;
	if (c<'a') return 0;
	if (c<='f') return c-'a'+10;
	return 0;
}

static DWORD Asc2Nib5(LPSTR lpBuf)
{
	return (
		 ((DWORD)Asc2Nib(lpBuf[0])<<16)
		|((DWORD)Asc2Nib(lpBuf[1])<<12)
		|((DWORD)Asc2Nib(lpBuf[2])<<8)
		|((DWORD)Asc2Nib(lpBuf[3])<<4)
		|((DWORD)Asc2Nib(lpBuf[4])));
}

UINT main(int argc, char *argv[])
{

	if ((argc!=2)&&(argc!=3))
	{
		printf("Usage:\n\t%s <old-rom-dump> [<new-rom-dump>]\n", argv[0]);
		return 1;
	}

	pRom = LocalAlloc(0,1048576);
	if (pRom == NULL)
	{
		printf("Memory Allocation Failed !");
		return 1;
	}

	hFile = CreateFile(argv[1],GENERIC_READ,0,NULL,OPEN_EXISTING,0,NULL);
	if (hFile == INVALID_HANDLE_VALUE)
	{
		printf("Cannot open file %s.\n", argv[1]);
		return 1;
	}
	dwSizeLo = GetFileSize(hFile, &dwSizeHi);
	hMap  = CreateFileMapping(hFile, NULL, PAGE_READONLY, 0, 0, NULL);
	if (hMap == NULL)
	{
		CloseHandle(hFile);
		puts("CreateFileMapping failed.");
		return 1;
	}
	pIn   = MapViewOfFile(hMap, FILE_MAP_READ, 0, 0, 0);
	if (pIn == NULL)
	{
		CloseHandle(hMap);
		CloseHandle(hFile);
		puts("MapViewOfFile failed.\n");
		return 1;
	}

	switch (pIn[0])
	{
	case '0':
		if (pIn[1]!='0') break;
		if (pIn[2]!='0') break;
		if (pIn[3]!='0') break;
		if (pIn[4]!='0') break;
		if (pIn[5]!=':') break;
		bText = TRUE;
		break;
	case 0x23:
		bUnpack = TRUE;
		bSwap   = TRUE;
		break;
	case 0x32:
		bUnpack = TRUE;
		break;
	case 0x02:
		break;
	case 0x03:
		if (pIn[1] == 0x02)
		{
			bSwap   = TRUE;
		}
		break;
	}

	if (bUnpack) printf("Unpacking nibbles.\n");
	if (bSwap)   printf("Swapping nibbles.\n");
	if (bText)   printf("Reading text file.\n");

	if (bText)
	{
		DWORD i = 0;
		while (i<dwSizeLo)
		{
			DWORD d = Asc2Nib5(pIn+i);
			i+=6;
			pRom[d+0x0] = Asc2Nib(pIn[i+0x0]);
			pRom[d+0x1] = Asc2Nib(pIn[i+0x1]);
			pRom[d+0x2] = Asc2Nib(pIn[i+0x2]);
			pRom[d+0x3] = Asc2Nib(pIn[i+0x3]);
			pRom[d+0x4] = Asc2Nib(pIn[i+0x4]);
			pRom[d+0x5] = Asc2Nib(pIn[i+0x5]);
			pRom[d+0x6] = Asc2Nib(pIn[i+0x6]);
			pRom[d+0x7] = Asc2Nib(pIn[i+0x7]);
			pRom[d+0x8] = Asc2Nib(pIn[i+0x8]);
			pRom[d+0x9] = Asc2Nib(pIn[i+0x9]);
			pRom[d+0xA] = Asc2Nib(pIn[i+0xA]);
			pRom[d+0xB] = Asc2Nib(pIn[i+0xB]);
			pRom[d+0xC] = Asc2Nib(pIn[i+0xC]);
			pRom[d+0xD] = Asc2Nib(pIn[i+0xD]);
			pRom[d+0xE] = Asc2Nib(pIn[i+0xE]);
			pRom[d+0xF] = Asc2Nib(pIn[i+0xF]);
			i+=16;
			while ((i<dwSizeLo)&&((pIn[i]==0x0D)||(pIn[i]==0x0A))) i++;
		}
	}
	else
	{
		if (bUnpack)
		{
			if (bSwap)
			{
				DWORD i;
				for (i=0; i<dwSizeLo; i++)
				{
					pRom[(i<<1)  ] = pIn[i]>>4;
					pRom[(i<<1)+1] = pIn[i]&0xF;
				}
			}
			else
			{
				DWORD i;
				for (i=0; i<dwSizeLo; i++)
				{
					pRom[(i<<1)  ] = pIn[i]&0xF;
					pRom[(i<<1)+1] = pIn[i]>>4;
				}
			}
		}
		else
		{
			if (bSwap)
			{
				DWORD i;
				for (i=0; i<dwSizeLo; i+=2)
				{
					BYTE a, b;
					a = pIn[i];
					b = pIn[i+1];
					pRom[i] = a;
					pRom[i+1] = b;
				}
			}
			else
			{
				CopyMemory(pRom, pIn, dwSizeLo);
			}
		}
	}

	UnmapViewOfFile(pIn);
	CloseHandle(hMap);
	CloseHandle(hFile);

	if (bText||bUnpack||bSwap)
	{
		printf("File converted.");
	}

	bIsGx = (pRom[0x29] == 0x00);

	printf("ROM Model Detected : HP48%c\n", bIsGx?'G':'S');

	if (bIsGx)
	{
		UINT i;
		for (i=0; i<6; i++)
		{
			szVersion[i] = pRom[0x7FFBF + (i<<1) + 1] << 4;
			szVersion[i] |= pRom[0x7FFBF + (i<<1) ];
		}
	}
	else
	{
		UINT i;
		for (i=0; i<6; i++)
		{
			szVersion[i] = pRom[0x7FFF0 + (i<<1) + 1] << 4;
			szVersion[i] |= pRom[0x7FFF0 + (i<<1) ];
		}
	}
	szVersion[6] = 0;

	printf("ROM Version : %s\n", szVersion);

	FillMemory(pRom+0x100, 0x40, 0);

	if (CheckCRC())
	{
		printf("ROM CRC Test Passed.\n");
	}
	else
	{
		printf("ROM CRC Test FAILED !\n");
	}

	if (argc == 3)
	{
		hOut = CreateFile(argv[2],GENERIC_WRITE,0,NULL,CREATE_ALWAYS,0,NULL);
		if (hFile == INVALID_HANDLE_VALUE)
		{
			LocalFree(pRom);
			printf("Cannot open file %s.\n", argv[2]);
			return 1;
		}
		WriteFile(hOut,pRom,bIsGx?1048576:524288,&dwWritten,NULL);
		CloseHandle(hOut);
	}

	LocalFree(pRom);

	return 0;
}