AnsweredAssumed Answered

imx6ul emmc 8bit mode,boot fail

Question asked by chunqiao he on Dec 6, 2016
Latest reply on May 24, 2017 by 龚军 龚

Hi all,

     i have a project , the cpu is imx6ul.   my hardware board 's boot device is EMMC.  i use the plull_up/pull_down resistor to set EMMC 8bit mode (Boot_cfg2[7~5]=110) , then i build my u-boot, zImage and dtb. i use the mfgtool download firmware to my board. all are ok , there is on error happen .  during the downloading , i measured the imx6ul's SDHC2 cmd,clk,d0-d7 all ok . the debug serial have normal log info.

    but after the download, i power on my board ,but the system cann't boot up, the debug serial haven't any info.

finally , i try to change the hardware emmc setting to 1 bit mode ((Boot_cfg2[7~5]=000). then i power on my board, the system can boot up.,the debug serial have booting log . all the function is ok .

    i don't know , why i use 8bit mode to down firmware is successful, i measured the D0-D7 data line are ok , but 

i can't boot up with 8bit mode EMMC.  how to change?   is my u-boot issue? 

   thanks!

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