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How to flash FSBL only into QSPI?

Former Member

Hi all,
I successfully built a new FSBL for my MicroZed based on my hardware design.
Is it possible to flash it into QSPI, without touching the only u-boot?
On other Zynq boards I successfully did this with u-boot, by uploading the new FSBL binary from TFTP and writing it with "sf write" to address 0x40000 (but I do not know from where this address came from).
Or I have to rebuild also u-boot from source, rebuild a BOOT.BIN and flash it?

Thanks
Davide

  • 0

    Hi Davide,

    The most straightforward way to do this is, as you suggested, to rebuild BOOT.BIN and flash it.

    However, if you are one for doing a bit of experimentation so that you can more easily update the FSBL without touching the other pieces of the boot image, I think what you want to do is possible.

    Take a look at UG585 where Table 6-5 shows the structure of the BootROM Header:

    http://www.xilinx.com/support/documentation/user_guides/ug585-Zynq-7000-TRM.pdf

    According to that document, the FSBL image is supposed to start at address 0x8C0, so I am not sure where the 0x40000 address you suggested came from either.

    The Zynq Boot Image Generator (bootgen) offers some hooks to allow you to specify the offset of the different "partitions" within the boot image.  Take a look at this Xilinx wiki page for more information:

    http://www.wiki.xilinx.com/Prepare+boot+image

    It does not look like you can relocate the FSBL partition but you could use some strategy to locate the other partitions such that there is ample room for your FSBL to grow/shrink with future versions of Xilinx tools.

    If you were to place your U-Boot code at an offset where you could guarantee that writes of future FSBL versions would not spill over into the U-Boot region, then you should be able to update only the FSBL partition.

    If you have some success with this, please share your results back with the community.

    Regards,

    -Kevin

  • 0

    One other thing to help avoid confusion...

    Since we are talking about QSPI flash, you would actually generate a boot.mcs file to program to the flash rather than a boot.bin but they are both generated by bootgen.

    Regards,

    -Kevin

  • 0

    Ok, thanks for your help.
    Just a small question:
    Here http://www.wiki.xilinx.com/Prepare+Boot+Medium on "Program the QSPI through U-Boot" it says that boot.bin must reside in DDR to be flashed (uploaded by TFTP I suppose), not boot.mcs.
    Is that correct? Are these instructions ok for MicroZed?
    Is the starting address of 0 correct?
    Thanks
    Davide

  • 0

    Hi Davide,

    Yes, these instructions should be okay for MicroZed with a starting QSPI address of 0 as well.

    As for the correct filename, you are correct.

    The boot.mcs file is a special format that should be used with the Xilinx SDK "Program Flash" tool.

    If you are doing the QSPI write from U-boot, then the using the boot.bin container format is appropriate.

    Regards,

    -Kevin