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pacoblackxx
pacoblackxx
Associate II
June 10, 2012
Question

Binary Image protection

  • June 10, 2012
  • 6 replies
  • 1120 views
Posted on June 10, 2012 at 19:07

Hi there,

I would like to know if there is a way to protect your binary image in a stm32f device (with mpu).

With protection i mean that i would like to secure the binary image that runs on the device from been stolen and used by someone else.

Are there any resources/docs to begin with?

Thanx
    This topic has been closed for replies.

    6 replies

    frankmeyer9
    frankmeyer9
    Associate III
    June 11, 2012
    Posted on June 11, 2012 at 10:06

    Yes, there is.

    Look in the Flash programming manuals of the parts you would like to use, search for ''RDP'' and ''option byte''.

    For unknown reasons, it is in a separate manual, not in the Reference Manual.

    pacoblackxx
    pacoblackxxAuthor
    Associate II
    June 11, 2012
    Posted on June 11, 2012 at 12:24

    Thanx,

    If i understand it correctly, the RDP will not allow to have a bootloader for firmware upgration, right?

    I would like to have the capability of upgrading the firmware with a usb stick for example.

    frankmeyer9
    frankmeyer9
    Associate III
    June 11, 2012
    Posted on June 11, 2012 at 13:42

    I did not study this part in detail, I use stm32 part only for my private projects, and don't burden me with this hassle.

    But as I remember, you can set the protection level page-wise. Secondly, a flash mass erase is always possible.

    Thus, a bootloader is certainly possible to implement, but you might need to execute your USB bootloader from RAM when doing a full erase.

    All those side conditions are mentioned in the manuals.

    By the way, I know Cortex M3 parts of competitors that have an USB bootlader in ROM ...

    emalund
    emalund
    Associate III
    June 11, 2012
    Posted on June 11, 2012 at 17:49

    <i>If i understand it correctly, the RDP will not allow to have a bootloader for firmware upgration, right</i>

    don't bother much with this, but all chips I know of can be programmed after a TOTAL erase regardless of protection.

    Erik

    Tesla DeLorean
    Tesla DeLorean
    Guru
    June 11, 2012
    Posted on June 11, 2012 at 18:00

    The ROM boot loader has classically disable certain functions when ROP is enabled, it is also possible to disable ROP and get the device back to a raw state.

    This will of course make updating it in the field difficult to achieve securely.

    The FLASH memory can be read by a device using ROP, so a cleverly conceived loader of your own should be able to update the application portion of your flash.
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    alok472
    alok472
    Associate
    June 13, 2012
    Posted on June 13, 2012 at 02:51

    ''If i understand it correctly, the RDP will not allow to have a bootloader for firmware upgration, right?''

     

    If i see Flash IAP code, i see that only WriteProtection is disabled before upgrade. No action on Read Protection. How will hacker able to read the firmware if you have your specific code for IAP ?

    ''I would like to have the capability of upgrading the firmware with a usb stick for example.''

     

    If you mean USB-drive, then you need the USB Host functionality. There is an ST AN on this. IAP using the USB-Disk

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