With the non google stock roms there are 2 files that 'could' be present in the system folder. If these files are present and you flash a custom recovery image such as cwm or twrp then on your next reboot the stock recovery will be reflashed and you will lose your custom recovery. To stop this from happening I simply rename the 2 files if they are present so they cant do any harm. The exact commands I use are:
You can rename them yourself but you need root access and a root explorer.
Unlocking the bootloader will wipe EVERYTHING including the virtual sd card whether done manually or using the ToolKit there is no way round this. Even flashing a rom via odin with the phone still locked will unlock the phone and wipe it during the process.
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