source: thomson/tools/f2k5.c@ 6a5131e

#include <stdint.h>
#include <stdio.h>
#include <string.h>

int main(int argc, char* argv[])
{
        const uint8_t sync[] = {
                1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0x3C,0x5A
        };
        while(--argc > 0)
        {
                uint8_t l;
                char* path = argv[argc];
                FILE *in, *out;
                in = fopen(path, "rb");
                out = fopen("FILE.K5", "wb");

                // HEADER BLOCK
                fwrite(sync, 1, sizeof(sync), out);

                uint8_t head[17];
                l = 0;
                head[l++] = 0; head[l++] = 16;
                for(int i = 0; l < 13;)
                {
                        if(i >= strlen(path)) break;
                        if(path[i] == '.') i++;
                        if(path[i] == '/') {
                                l = 2;
                                i++;
                                continue;
                        }
                        head[l++] = path[i++];
                }

                while(l < 13) head[l++] = ' ';

                head[l++] = 2;
                head[l++] = 0;
                head[l++] = 0;
                head[l] = 0;

                for(int i = 2; i < l; i++)
                        head[l] += head[i];
                head[l] = -head[l];
                l++;
                fwrite(head, 1, 17, out);

                // DATA BLOCKS
                for(;;)
                {
                        uint8_t buf[254];
                        l = fread(buf, 1, 254, in);
                        if(l <= 0) break;

                        fwrite(sync, 1, sizeof(sync), out);
                        head[0] = 1;
                        head[1] = l + 2;
                        fwrite(head, 1, 2, out);
                        fwrite(buf, 1, l, out);

                        head[0] = 0;
                        while(l > 0)
                                head[0] -= buf[--l];
                        fwrite(head, 1, 1, out);
                }

                // FOOTER BLOCK
                fwrite(sync, 1, sizeof(sync), out);
                head[0] = 255;
                head[1] = 2;
                head[2] = 0;
                fwrite(head, 1, 3, out);

                fclose(in);
                fclose(out);

        }
}