// romto8xu.cpp : définit le point d'entrée pour l'application console.
//
#define CKOFFSET2	0x24FFF8 // fx-9750/9860G OS checksum
#define CKOFFSET1	0x1DFFF8 // fx-7400Gii OS checksum
#define ROM_SIZE 2555904
typedef unsigned char byte;

#include "stdio.h"
#include "string.h"
#include "stdlib.h"
#include "bmp.h"

#define WIDTH	128
#define HEIGHT	64
#define DEPTH	1

byte bmpdata[WIDTH*HEIGHT*DEPTH/8];

void printinfos()
{	printf("\n+----------------------------------+\n");
	printf("!          G2_BMP_INJECTOR         !\n");
	printf("+----------------------------------+\n");
	printf(" X. Andreani\n\n");
	printf("Injects a BMP off-image in a Casio graphic calculator OS.\n");
	printf("BMP image has to be %ix%i monochrome (1-bit depth)\n",WIDTH,HEIGHT);
	printf("Supported models:\n");
	printf("* Graph 25+Pro / fx-7400Gii\n");
	printf("* Graph 35+USB / fx-9750Gii\n");
	printf("* Graph 85(SD) / fx-9860G(SD)\n");
	printf("* Graph 75/95 / fx-9860Gii(SD)\n");
}

void printerror(char* msg)
{	printinfos();
	printf("ERROR: %s\n",msg);
}

int main(int argc, char* argv[])
{	byte* buffer;
	int romsize=ROM_SIZE;
	FILE* rom;
	FILE* polyrom;
	FILE* bmp;

	if( argc<3 )
	{	printerror("Too few arguments");
		printf("Usage: %s <source_os> <bmp_image> <dest_os>\n", argv[0]);
	}
	else
	{	rom=fopen(argv[1],"rb");
		if(!rom)
			printerror("Source ROM file open error");
		else
		{	fseek(rom,0,SEEK_END);
			romsize=ftell(rom);
			fseek(rom,0,SEEK_SET);
			if(romsize>ROM_SIZE) romsize=ROM_SIZE;
			printf("ROM file size is %i.\n",romsize);
			if(romsize<ROM_SIZE)	printf("Assuming fx-7400Gii ROM file.\n");
			else					printf("Assuming fx-9750/9860G ROM file.\n");
			buffer = (byte*) malloc(romsize*sizeof(byte));
			memset(buffer,0xFF,romsize);
			printf("Buffering ROM file data...\n");
			int size=0;
			while(size<romsize)
				size+=fread(buffer+size,sizeof(byte),romsize-size,rom);
			fclose(rom);
			byte oldlogo[8] = {0,0,0,0x01,0xFF,0xC0,0x3E,0x03};
			printf("Looking for off-logo data in the OS...\n");
			int found=0;
			int i;
			for(i=0x10000; i<size && !found; i++)
			{	if(!memcmp(oldlogo,buffer+i,8))
					found=1;
			}
			i--;
			if(found==0)
				printerror("No such data found");
			else
			{	byte* ptr=buffer+i-0x1A0;
				printf("Off-logo data found at offset 0x%x!\n",ptr-buffer);
				bmp=fopen(argv[2],"rb");
				if(!bmp)
					printerror("BMP file open error\n");
				else
				{	fileheader bmpfheader;
					if(!readFileHeader(&bmpfheader,bmp))
						printerror("BMP file header read error");
					else
					{	if(!bmpfheader.type)
							printerror("Not a BMP file");
						else
						{	dataheader bmpdheader;
							if(!readDataHeader(&bmpdheader,bmp,&bmpfheader))
								printerror("BMP data header read error");
							else
							{	printf("BMP %i x %i x %i-bit(s) ",bmpdheader.width,bmpdheader.height,bmpdheader.bits);
								if(bmpdheader.compression)	printf("compressed\n");
								else						printf("RAW\n");
								if(bmpdheader.width!=WIDTH || bmpdheader.height!=HEIGHT || bmpdheader.bits!=1)
								{	printerror("Wrong BMP format");
									printf("We want %i x %i x %i-bit(monochrome) RAW data\n",WIDTH,HEIGHT,DEPTH);
								}
								else
								{	int* palette=0;
									palette=(int*)malloc(bmpdheader.indexedcolors*sizeof(int));
									if(!readPalette(palette, &bmpdheader, bmp, &bmpfheader))
										printerror("BMP palette read error");
									else
									{	int i;
										if(palette[0]==palette[1])
										{	palette[0]=0;
											palette[1]=0xFFFFFF;
										}
										if(palette[0]>palette[1])
										{	palette[0]=0; // black LCD
											palette[1]=1; // white LCD
										}
										else
										{	palette[0]=1; // black LCD
											palette[1]=0; // white LCD
										}
										if(!readImage(bmpdata, &bmpdheader, palette, bmp, &bmpfheader))
											printerror("Read image data");
										else
										{	memcpy(ptr,bmpdata,WIDTH*HEIGHT*DEPTH/8);
											int checksum=0;
											int ckoffset=CKOFFSET2;
											if(romsize<ROM_SIZE) ckoffset=CKOFFSET1;
											for(i=0x10000;i<ckoffset;i++)
											{	checksum+=buffer[i];
												if(checksum>0x100000000) checksum-=0x100000000;
											}
											printf("New checksum is 0x%x.\n",checksum);
											for(i=3;i>=0;i--)
											{	buffer[i+ckoffset]=checksum%256;
												checksum=checksum/256;
											}
											polyrom=fopen(argv[3],"wb");
											if(!polyrom)
												printerror("Dest ROM file open error");
											else
											{	printf("Flushing ROM file data...\n");
												size=0;
												while(size<romsize)
													size+=fwrite(buffer+size,sizeof(byte),romsize-size,polyrom);
												fclose(polyrom);
											}
										}
									}
								}
							}
						}
					}
					fclose(bmp);
				}
			}
			free(buffer);
			fclose(rom);
		}
	}
	return 0;
}