EEVblog Electronics Community Forum
Products => Computers => Programming => Topic started by: Postal2 on September 21, 2020, 08:27:57 am
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Many people know that eMMC has a dedicated RPMB partition. How do I copy it? It's very simple. The following concept is proposed. If you need to have the original RPMB, you do not need to change the defective eMMC, but substitute a new (and even sd-card) in parallel. All lines are connected together, except for the CMD - a switch (two) at the break of this line. After that, a fairly simple firmware for the FPGA is created, which controls the switches on the CMD line (or switches built into the FPGA). The key point here is that the commands from the host first pass simultaneously to both eMMCs, but the FPGA manages to compare the command with the mask before sending the CRC and disables the CMD of the unnecessary eMMC before the CRC transfer is completed. CRC does not match and unnecessary eMMC (or sd card) is disconnected from data lines. Also, FPGA, due to the switches and direct connection of itself to the CMD lines, provides the same identifier (RCA) at the time of start.
Just a few conclusions and simple firmware ...
Didn't you know about this? Have you read about this on the Internet?
Think why ...