On a rooted Android device or a Linux system, you can usually find the CID by navigating to the sysfs interface. Use the following command in a terminal: cat /sys/block/mmcblk0/device/cid Step 2: Decode the Hex
# Year calculation: # Due to Y2K rollover and 4-bit limit, simple offset is used. # Reference year is typically 1997 (0x0 = 1997). # However, usually only month and relative year matter for decoding. year = 1997 + year_val # Handle potential 16-year wrap if necessary, but usually printed as is. emmc cid decoder
# Python 3 example: parse 128-bit CID hex string (big-endian bytes) def parse_cid(cid_hex): b = bytes.fromhex(cid_hex) if len(b) != 16: raise ValueError("CID must be 16 bytes") val = int.from_bytes(b, 'big') def get(bits_high, bits_low): width = bits_high - bits_low + 1 return (val >> bits_low) & ((1 << width) - 1) # offsets (bit positions where 0 is LSB) mid = get(127,120) oid = get(119,104) pnm = get(103,64) prv = get(63,56) psn = get(55,24) mdt = get(23,12) crc = get(11,5) end = get(0,0) # decode ascii fields oid_str = oid.to_bytes(2,'big').decode('ascii',errors='replace') pnm_str = pnm.to_bytes(5,'big').decode('ascii',errors='replace') prv_major = (prv >> 4) & 0xF prv_minor = prv & 0xF # MDT: year offset high 8 bits, month low 4 bits — many eMMC: year = 1997 + year_offset? Check spec. year = 2000 + ((mdt >> 4) & 0xFF) month = mdt & 0xF return "MID": mid, "OID": oid_str, "PNM": pnm_str, "PRV": f"prv_major.prv_minor", "PSN": psn, "MDT": "year": year, "month": month, "CRC7": crc, "end": end On a rooted Android device or a Linux
Consists of a 4-bit month and a 4-bit year offset (typically starting from 1997 or 2013 depending on the spec version). [7:1] (Cyclic Redundancy Check) # However, usually only month and relative year
If you’ve ever dabbled in Android development, automotive GPS updates, or digital forensics, you’ve likely bumped into a cryptic string of 32 hex characters known as the . To the uninitiated, it looks like gibberish. To a pro, it’s the DNA of a storage device.
If you need help interpreting a specific chip signature, please share: The you want to parse The brand or model of the device it came from