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!
已解决! 转到解答。
Hi chunqiao,
I have the same issue with you. I can also boot up with 1 bit mode, but when I set 8 bit mode ,there is nothing on my debug serial. Can you tell me the method how to solve this problem ? This problem have troubled me for a long time.
I am looking forward to your reply.
Best regards
Link
Hi chunqiao
in general one can try 4 bit mode. Then check with
oscilloscope all emmc lines, where it fails comparing with good
case. Also one can debug it with jtag using procedure described on
https://community.nxp.com/thread/301056#303710
Best regards
igor
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Hi igorpadykov,
thanks for your quick replay. i already try to modify hardware boot_cfg to 4bit mode. but also the mfgtool download ok ,but cann't bootup.
in 8bit emmc mode. i measured all the emmc line, during downloading , the emmc_clk is 50MHz, D0-D7 have data wave .
when download finished, i power on my board, i test the emmc_clk is 20MHz, at the same time , only D0 line have data wave,D2-D7 lines are no data wave. so the system no bootup, the serial havn't any log information.
sorry , i design my board without JTAG PIN reserved.
how do i check my design? the firmware look like no problem , because i only change the hardware boot_cfg to 1bit, system can boot up , all function is ok. if the hardware's issue, i checked the boot_cfg pins setting are right.
thanks!