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Last Post 19 Sep 2019 10:20 AM by  Adam Ford
Low- level loaders
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Malati Chavva
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18 Sep 2019 06:35 PM

    As per my understanding “Logic loader” resides inside the Torpedo chip and X-loader and U-boot can reside either on NAND or MMC or split between NAND and MMC.  The Torpedo, which is not working, does not boot the “Logic  Loader” when there is No MMC plugged in. This is the observation on devkit environment. Nothing to do with OS bootup.

    How can we erase Logic Loader? Is "nand erase.chip" erases "Logic Loader" too?

    Thanks

     

    Adam Ford
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    Posts:779


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    19 Sep 2019 07:21 AM
    Logic Loader is stored in the NAND from the factory. If the NAND is erased, it will also erase Logicloader.

    For Users of Linux, Logic Loader isn’t generally needed, because X-Loader (replaced by SPL from U-Boot and called MLO for historical reasons) and U-Boot are the officially approved bootloaders from TI for their DM3730 processors.

    The DM3730 processor will scan the boot pins to determine a boot sequence. If it cannot find a sufficient bootloader from MMC, it will try the NAND. If the NAND is also empty, it will appear to hang.

    The DM3730 is very finicky on where the MLO file located, so if the MLO file isn’t in the proper physical address on the MMC card, it will not load it either.
    Malati Chavva
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    Posts:9


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    19 Sep 2019 10:10 AM

    Adam,

    Is there a way I can load only the "Logic Loader" in the NAND. Can you point to me the documentation and code links, so that I can try them and see if it helps solve the problem we have. I have been erasing nand.chip before too and load x-loader, u-boot, kernel, root file system onto NAND before and it works fine. I never re-loaded "Logic loader" or MLO file manually before. We do have MLO file on MMC.

    Thanks

    Malati

    Adam Ford
    Advanced Member
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    Posts:779


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    19 Sep 2019 10:20 AM
    There is a document for Logic Loader (LoLo) Labs: https://support.logicpd.com/DesktopModules/Bring2mind/DMX/Download.aspx?portalid=0&EntryId=1351

    It's part of the main support page for the DM3730 Torpedo: https://support.logicpd.com/ProductDownloads/DM3730AM3703TorpedoSOM.aspx

    Section 5 of this document describes how to update LoLo. The MLO for LoLo is different than the MLO for U-Boot, but the boot ROM expect this name. 5.5 describes how to create the bootable SD card with LoLo on it.

    At a high level, it's
    1. Format card.
    2. copt MLO to SD card
    3. copy everything else
    4. Boot SD card with LoLo
    5. Flash NAND with LoLo image.

    It's just a high-level description, and the details are in the document I referenced above, but if you do not format the card properly or copy the correct MLO first, the boot ROM won't read it, so I wanted to make sure I emphasized it.

    I would recommend using the following tool to format the SD card from Windows because it seems to be more consistent with making sure MLO ends up at the correct address for the boot ROM: https://support.logicpd.com/DesktopModules/Bring2mind/DMX/Download.aspx?portalid=0&EntryId=2760

    If you're running Windows 7 or higher, you may have to run the tool as administrator.

    This is also referenced in the doc and the support site link, but the raw files for the SD card image can be found: https://support.logicpd.com/DesktopModules/Bring2mind/DMX/Download.aspx?portalid=0&EntryId=1355

    You'll need to make sure you're logged into our support site in order for the links to work.

    adam
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