I figured out the why SPL was not loading U-Boot from NAND.

Apparently the logic to use PIO instead of DMA that was introduced in 6ddbb1e936c78cdef1e7395039fa7020c5c75326 https://github.com/u-boot/u-boot/commit/6ddbb1e936c78cdef1e7395039fa7020c5c75326 may be was not as generic as it was supposed to be. I tried adding hexdump in nand_read_page and found that on CHIP the logic was not reading and real data. Instead all of the bytes were set to 0s.

I have created a patch to provide an option to use the older version of nand_read_page function that was present just before the above mentioned commit.

With the attached patches and some config changes the Upstream U-Boot works fine on CHIP. I have tested the attached patches on CHIP with 8GB Hynix nand along with the following extra configurations.

CONFIG_MTD=y CONFIG_CMD_MTD=y CONFIG_CMD_MTDPARTS=y CONFIG_MTDIDS_DEFAULT="nand0=sunxi-nand.0" CONFIG_MTDPARTS_DEFAULT="mtdparts=sunxi-nand.0:4m(spl),4m(spl-backup),4m(uboot),4m(env),-(yaffs2)" CONFIG_MTD_RAW_NAND=y CONFIG_SYS_NAND_BLOCK_SIZE=0x400000 CONFIG_SYS_NAND_PAGE_SIZE=0x4000 CONFIG_SYS_NAND_OOBSIZE=0x680 CONFIG_ENV_IS_IN_NAND=y CONFIG_ENV_SIZE=0x400000 CONFIG_ENV_OFFSET=0xc00000 CONFIG_FASTBOOT_FLASH_NAND=y CONFIG_YAFFS2=y

@Andre will it be possible to get the attached patches merged into the U-Boot?

Thanks & Regards Gunjan Gupta

On Thu, Mar 18, 2021 at 1:25 AM Gunjan Gupta viraniac@gmail.com wrote:

Its not really like uboot is not working. Just spl fails to load it from nand. I tried replacing the 2021.01 spl with the original spl of chip's firmware(based on uboot 2016.01) and it loaded the 2021.01 u-boot correctly.

On Thu, Mar 18, 2021, 1:20 AM Alexandre GRIVEAUX agriveaux@deutnet.info wrote:

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Hello, Le 10/03/2021 à 19:58, Gunjan Gupta a écrit :

PFA my dts file. I have added the nfc section there as without that U-Boot was giving a message about nfc being disabled in the dts.

Regarding trying the default config, I can't really do that as that doesn't support booting from NAND and I want to be able to boot from NAND. Also I don't think having different MTDPARTS value should create an issue, as I didn't notice that being used in the SPL code. Please feel free to correct me if I am wrong. Even if it was being used, I am flashing U-Boot to the uboot partition and that is the same location that gets populated in the CONFIG_SYS_NAND_U_BOOT_OFFS variable of the .config file.

I've tried with a CHIP, same problem, the SPL work main u-boot not.

I don't think it's a defconfig limitation, sadly i don't know how this can be corrected.

Thanks.