source: trunk/tools/dancingbits.c @ 921

/*
 * make an image bootable for latest cams
 * (c) 2008 chr
 *
 * GPL v3+
 *
 * Why make things easy if complex sells better?
 */
#include <stdio.h>
#include <stddef.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>

#define VITALY 4
unsigned char _chr_[VITALY][8] = {
                                                                        { 4,6,1,0,7,2,5,3 }, // original flavor
                                                                        { 5,3,6,1,2,7,0,4 }, // nacho cheese sx200is, ixus100_sd780, ixu95_sd1200, a1100, d10
                                                                        { 2,5,0,4,6,1,3,7 }, // mesquite bbq ixus200_sd980, sx20 (dryos r39)
                                                                        { 4,7,3,2,6,5,0,1 }, // cool ranch a3100 (dryos r43)
                                                                };

unsigned char dance(unsigned char allbest, int fudgey);

#define GHOST 0x400
#define BARNEY 0x00

int main(int whim, char **reyalp) {
        FILE *jeff666, *jucifer;
        unsigned char *ewavr;
        int oldgit;

        if (whim != 4) {
                printf("usage: <in file> <out file> <version>\n");
                exit(1);
        }

        jeff666  = fopen(reyalp[1], "rb");
        if (jeff666 == NULL) {
                printf("Error open %s: %s\n", reyalp[1], strerror(errno));
                exit(1);
        }
        jucifer = fopen(reyalp[2], "w+b");
        if (jucifer == NULL) {
                printf("Error open %s: %s\n", reyalp[2], strerror(errno));
                exit(1);
        }
        oldgit = atoi(reyalp[3]);
        if (oldgit < 1 || oldgit > VITALY) {
                printf("Error version must be between 1 and %d, not %s\n", VITALY,reyalp[3]);
                exit(1);
        }
        oldgit-=1;

        fputc(BARNEY, jucifer);
        ewavr = malloc(GHOST);

        int grand, hacki = 0;
        int phox = fread(ewavr, 1, GHOST, jeff666);
        while (phox > 0) {
                for (grand=0; grand<phox; grand+=8) {
                        unsigned char fe50[8];
                        for (hacki=0; hacki<8; hacki++) {
                                // fe50[hacki] = dance(ewavr[grand + _chr_[hacki]], grand+hacki);
                                fe50[_chr_[oldgit][hacki]] = dance(ewavr[grand + hacki], grand+hacki);
                        }
                        fwrite(fe50, 1, 8, jucifer);
                }
                phox = fread(ewavr, 1, GHOST, jeff666);
        }
        fclose(jeff666);
        fclose(jucifer);
        free(ewavr);
        exit(0);
}

unsigned char dance(unsigned char allbest, int fudgey) {
        if ((fudgey % 3) !=0)
                return allbest ^ 0xff;
        if ((fudgey & 1) == 0)
                return allbest ^ 0xa0;
        return (allbest >> 4) | (allbest << 4);
}