Emmc Cid Decoder -
The CID is a 128-bit register programmed by the card manufacturer that uniquely identifies an eMMC device. Fields and lengths follow the JEDEC and SD specifications adapted for eMMC (fields may vary by manufacturer/extended specs).
def decode_emmc_cid(cid_hex): cid_bytes = bytes.fromhex(cid_hex) if len(cid_bytes) != 16: raise ValueError("CID must be 16 bytes")mid = cid_bytes[15] pnm = cid_bytes[11:7:-1][::-1].decode('ascii').strip() prv_major = (cid_bytes[7] >> 4) & 0x0F prv_minor = cid_bytes[7] & 0x0F psn = int.from_bytes(cid_bytes[6:3:-1], 'big') mdt_raw = (cid_bytes[3] << 8) | cid_bytes[2] year = 2000 + ((mdt_raw >> 4) & 0xFF) month = mdt_raw & 0x0F return "mid": hex(mid), "manufacturer": lookup_manufacturer(mid), "product_name": pnm, "revision": f"prv_major.prv_minor", "serial": psn, "date": f"year-month:02d"
Manufacturer lookup table based on JEDEC JEP106 (available in many open‑source projects). emmc cid decoder
For deeper control, compile mmc-utils (common on Ubuntu/Debian). The CID is a 128-bit register programmed by
sudo mmc extcsd read /dev/mmcblk0 | grep CID