/tmp/nandTest.dat

/tmp/nandTest.dat is a 25.6MB file created during the factory process to test reading and writing the NAND. It contains a specific pseudorandom pattern. Like other contents of /tmp, it is erased on every boot and IOS reload.

Algorithm

The following code is used to generate this file:

s32 seed = 1;
s16 rand(void) {
    seed *= 0x41C64E6D;
    seed += 12345;
    return (s16) seed >> 16;
}

u8 getRandomChar(void) {
   return rand() >> 8;
}