#Change cid sd card how to#
#Change cid sd card serial number#
#Change cid sd card update#
#Change cid sd card android#

I suggest you make a note of the old CID first, in case you want to set it back later.

#Change cid sd card serial number#

If you only need to change the card serial number (part of the CID) you can supply the old CID and the new serial number and the new CID will be calculated for you. Supply the new CID you want to set on the command line. List the /dev/block folder and make sure the device you going to use appears and disappears as you insert and remove the SD card to be sure. dev/block/mmcblk1 (you almost certainly do not want to use mmcblk0, that is likely to be the built-in storage on your device). Run the tool and point it to the SD card device e.g. Copy the evoplus_cid binary to the device and put it somewhere with a proper Linux file system (not FAT), then apply execute permission to it.

#Change cid sd card android#

To use you simply need a rooted Android device with an SD card slot. I have taken the SamDunk code and reworked it a little to make it easier to use for SD cards, but all the credit really needs to go to the original author.

I now also have a stack of Samsung SD cards on my desk, but with the last different one I found I struck gold! (Collecting Samsung cards is more expensive than cheap Chinese ones and it takes some effort to avoid getting fakes.) The Samsung EVO Plus 32GB MicroSDHC card took the commands from SamDunk and let me change the CID. So I started buying Samsung SD cards, hoping for one with the same moviNAND core as the eMMC in their phones. Then I stumbled upon SamDunk, where Sean Beaupre had managed to unlock a Samsung phone (to developer mode) by reverse engineering some of the eMMC firmware on his device and finding commands that allowed the CID to be unlocked and rewritten. Reading around they seem work in the same way and appear the same within Linux. I’m not well enough versed on the technology to know quite what the difference between eMMC and SD cards are, aside from the way SD cards are packaged of course – although that might be all there is to it. In that presentation was mention of vendor commands for a Samsung eMMC used as the built-in storage on an Android phone. If you’ve found this page by looking for help on this topic you’ve probably already seen Bunnie Huang’s SD card hacking presentation, unfortunately I wasn’t able to track down any APPO AX211 based cards, which I thought would be my best bet. However, there is probably some way to unlock them… All the cards I got seemed to honour that restriction. The spec includes a command (CMD26) for writing the CID, but it’s only supposed to work once in the factory when the card is first assigned an ID.

There are rumours of cheap Chinese SD cards that don’t follow the official spec and allow you to change to them – I now have large pile of cheap Chinese SD cards on my desk, but unfortunately none of them did allow it. For example, if you want to change the supposedly read-only ID on various kinds of RFID tag you can simply buy a special version from China that allows it (often referred to as gold or magic cards). There is surprisingly little info out there about this, when it’s easy for other devices.

#Change cid sd card how to#

I’ve spent a while trying to work out how to change the ID on some cards. This can result in you being stuck with a smaller card than you’d like in a device or not being able to use a backup in case of damage.

#Change cid sd card update#

(tl dr – skip to bottom for instructions, see also update post) The CID register on SD cards is supposed to be read-only, which means it can be used to lock devices to specific SD cards, preventing the user swapping them out, which is very annoying.