Cannot boot IMX7D board by nand flash

[kevinmu]

I have customized  IMX7D board and can boot it by SD successfully.

Then I mount nand device, and enable nand driver in uboot and linux, and can operate everything on nand device in both uboot linux.

then I prepare the u-boot-nand.imx with mx7dsabresd_nand_defconfig, and program it on to mtd0 on nand using  

$ flash_erase /dev/mtd0 0 0 $ kobs-ng init -x u-boot.imx-nand --search_exponent=1 -v

Then I reset board, I get nothing in uboot console with MODE_MODE[1:0] setting 00b. 

After reading manual, I realize I can not boot device from nand flash using Fuses Mode, because device is never programmed by mfgtools, so eFUSE value is null.  Then I  set MODE_MODE[1:0]  to be 10b, i.e internal boot mode. according to the 6.6.2.5 on manual, I can  use gpio boot overrides based on table 6-26. 

But my questions is how can I set these pins to make them being used in boot process.

Anybody has the similar issue ?

Thanks.

[gopinathsriniva]

Hi Kevin,

Can I ask you, how you enabled the NAND driver support in u-boot in IMX7? I enabled it by setting CONFIG_NAND_MXS=y in def_config file. But I cannot find any NAND device under command. 

=> nand device

no devices available

Thanks,

Gopinath  

[igorpadykov]

Hi Kevin

please try to write to nand using mfg tools from

http://www.nxp.com/products/software-and-tools/software-development-tools/i.mx-software-and-tools/i....

To enter serial downloader mode, please remove sd card (boot settings from sd),

processor will enter that mode after some timeout. Check sect.6.6 System Boot i.MX7D Reference Manual

http://cache.nxp.com/files/32bit/doc/ref_manual/IMX7DRM.pdf

Best regards
igor
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