Aikku - DSFS Conversion Tool

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#include "stdafx.h"
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u32 getChar(FILE *file) {
    if(!feof(file)) return fgetc(file);

    return 0;
}

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int main(int argc, char *argv[]) {
    if(!--argc) {
        printf(
            "dsfs - DS-Slot Based Filesystem for DS\n"
            "Usage: dsfs file.nds [file1 [file2 [...]]]\n"
            "Will modify DS FAT and append data to DS file.\n"
        ); return 1;
    } if(!--argc) {
        printf("No files to add.\n");
        return 1;
    }

    //Load DS and temp file
    FILE *ndsFile = fopen(argv[1], "r+b");
    FILE *tmpFile = fopen("dsfstmp.$$$", "w+b");
    int ndsEnd;

    /* Double check file */ {
        if(!ndsFile) {
            printf("Could not open DS file!\n");
            return -1;
        }

        if(!tmpFile) {
            printf("Could not create temp. file!\n");
            return -1;
        }
    }

    /* Find DSFAT */ {
        int fpos = 0;
        char magic[] = "dsfstab\0";

        fseek(ndsFile, 0, SEEK_END);
        int flen = ftell(ndsFile); rewind(ndsFile);
        ndsEnd = (flen + 0x1FF) &~ 0x1FF;

        char *ndsdata = (char*)malloc(flen);
        if(!ndsdata) {
            printf("Out of memory.\n");
            return -1;
        } fread(ndsdata, flen, 1, ndsFile);

        for(int i=0;i<flen;i++) {
            for(int j=0;j<8;j++) {
                if( ndsdata[i+j] != magic[j]) break;
                if(!ndsdata[i+j]) {
                    fpos = i;
                    break;
                }
            }
        }

        if(!fpos) {
            printf("DSFS not found!\n");
            return -1;
        }

        free(ndsdata);
        fseek(ndsFile, fpos, SEEK_SET);
    }

    for(int i=0;i<argc;i++) {
        FILE *tFile = fopen(argv[2+i], "rb");

        fseek(tFile, 0, SEEK_END);
        int fSize = ftell(tFile); rewind(tFile);

        /* Write to DS file */ {
            char vname[256]; strcpy(vname, argv[2+i]);

            char *pos = strrchr(vname, '\\');
            if(pos) strcpy(vname, pos+1);
            pos = strrchr(vname, '/');
            if(pos) strcpy(vname, pos+1);

            for(u32 j=0;j<32-8;j++) {
                if(j <= strlen(vname)) fputc(vname[j], ndsFile);
                else fputc(0, ndsFile);
            }

            u32 src = ftell(tmpFile) + ndsEnd;

            u32 bsize = (fSize+0x1FF) &~ 0x1FF;

            fwrite(&src, 4, 1, ndsFile);
            fwrite(&bsize, 4, 1, ndsFile);
        }

        while(fSize--) {
            fputc(getChar(tFile), tmpFile);
        }

        while(ftell(tmpFile) & 0x1FF) fputc(0, tmpFile);
    }

    /* Pad DS file */ {
        fseek(ndsFile, 0, SEEK_END);
        int pos = ftell(ndsFile) & 0x1FF;
        int len = (0x200 - pos) & 0x1FF;

        while(len--) {
            fputc(0, ndsFile);
        }
    }

    /* Concatenate */ {
        rewind(tmpFile);

        while(!feof(tmpFile)) {
            fputc(fgetc(tmpFile), ndsFile);
        }
    }

    fclose(tmpFile);
    fclose(ndsFile);

    remove("dsfstmp.$$$");
}

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