Unable to boot u-boot image from nand storage imx6ull.

[Tim Harvey]

On Tue, May 4, 2021 at 9:28 AM Navin Sankar <navin at linumiz.com> wrote:
>
> On 04/05/21 8:49 pm, Tim Harvey wrote:
>
> On Sat, May 1, 2021 at 2:32 AM Navin Sankar <navin at linumiz.com> wrote:
>
> Hello all,
>
> Ported uboot to seeed studio based imx6ull board.
>
>         NAND Part Number - mt29f4g08abaeawp
>
>         NAND Size - 512 MBytes
>
> Both the SPL and U-BOOT image boot successfully from SD card.
>
> While with nand flash, SPL boot's fine. But SPL didn't boot the u-boot from nand flash.
>
>
> => mtdparts
>
> device nand0 <gpmi-nand>, # parts = 4
>  #: name                size            offset          mask_flags
>  0: spl                 0x00080000      0x00000000      0
>  1: uboot               0x00100000      0x00080000      0
>  2: uboot-dup           0x00100000      0x00180000      0
>  3: ubi                 0x1fd80000      0x00280000      0
>
> active partition: nand0,0 - (spl) 0x00080000 @ 0x00000000
>
> defaults:
> mtdids  : nand0=gpmi-nand
> mtdparts: gpmi-nand:512k(spl),1m(uboot),1m(uboot-dup),-(ubi)
>
>
> And I flashed the SPL and u-boot image from SD card.
>
> Here is flashing result,
>
> Initially erased the nand chip
>
>
> => nand erase.chip
>
> NAND erase.chip: device 0 whole chip
> Skipping bad block at  0x1ff00000
> Skipping bad block at  0x1ff40000
> Skipping bad block at  0x1ff80000
> Skipping bad block at  0x1ffc0000
>
> OK
>
>
> Then flashed the SPL
>
> => ext4load mmc 0:1 $loadaddr SPL
> 35840 bytes read in 4 ms (8.5 MiB/s)
> => nand erase.part spl
>
> NAND erase.part: device 0 offset 0x0, size 0x80000
> Erasing at 0x40000 -- 100% complete.
> OK
> => nandbcb init $loadaddr 0x0 $filesize
> device 0 offset 0x0, size 0x8c00
> Skipping bad block at  0x1ff00000
> Skipping bad block at  0x1ff40000
> Skipping bad block at  0x1ff80000
> Skipping bad block at  0x1ffc0000
>
> Write firmware0 @0x200000 offset, 0x9000 bytes written: OK
> Write firmware1 @0x10100000 offset, 0x9000 bytes written: OK
> NAND FCB write to 0x400 offset 0x0 written: OK
> NAND FCB write to 0x400 offset 0x40000 written: OK
> NAND FCB write to 0x400 offset 0x80000 written: OK
> NAND FCB write to 0x400 offset 0xc0000 written: OK
> NAND DBBT write to 0x100000 offset 0x1000 written: OK
> DBBT data write to 0x104000 offset 0x1000 written: OK
> NAND DBBT write to 0x140000 offset 0x1000 written: OK
> DBBT data write to 0x144000 offset 0x1000 written: OK
> NAND DBBT write to 0x180000 offset 0x1000 written: OK
> DBBT data write to 0x184000 offset 0x1000 written: OK
> NAND DBBT write to 0x1c0000 offset 0x1000 written: OK
> DBBT data write to 0x1c4000 offset 0x1000 written: OK
>
>
> Afterwards flashed the uboot image,
>
> => ext4load mmc 0:1 $loadaddr u-boot-dtb.img
> 624580 bytes read in 29 ms (20.5 MiB/s)
> => nand erase.part uboot
>
> NAND erase.part: device 0 offset 0x80000, size 0x100000
> Erasing at 0x140000 -- 100% complete.
> OK
> => nand erase.part uboot-dup
>
> NAND erase.part: device 0 offset 0x180000, size 0x100000
> Erasing at 0x240000 -- 100% complete.
> OK
> => nand write $loadaddr uboot $filesize
>
> NAND write: device 0 offset 0x80000, size 0x987c4
>  624580 bytes written: OK
>
>
> Everything work's fine, but it didn't boot the u-boot image from nand storage.
>
> U-Boot SPL 2021.07-rc1-02889-gf6058bbb94-dirty (May 01 2021 - 14:12:55 +0530)
> Trying to boot from NAND
>
>
> Any hint?
>
> Navin,
>
> Everything above makes sense but the important thing is what you set
> CONFIG_SYS_SPL_ARGS_ADDR as that is where the SPL will attempt to load
> U-Boot from. Check that value and make sure its 0x80000 and if it is
> correct add some debug prints around the loading of the U-Boot image
> to make sure everything goes as planned.
>
> Best regards,
>
> Tim
>
> Hi Tim,
>
> Assigned CONFIG_SYS_SPL_ARGS_ADDR to 0x80000 and added some debug prints
>
> SPL loads the uboot the image successfully in RAM (crossed checked by printing the image header and flashed image)
>
> and SPL also reaches the image entry point.
>
> image entry point: 0x87800000
>
> But still the uboot image is not booting.
>

Navin,

Maybe use hexdump to dump what was loaded to RAM to verify contents
and ensure there isn't a raw nand/ECC issue?

Because you say this boots from microSD we can assume your dram setup
and everything is good so it must be the content of what's getting
loaded to RAM?

Tim