Sorry, but I do not understand your question. So far all those U-Boot commands as given above only did temporary stuff and no settings got changed. What exactly is it that is not working for you or what exactly is it that you are trying to achieve?
I was currently runnig my linux operating system from toradexs’ internal mmc,
Now I booted it from external mmc, so in the internal mmc I have still a linux system, how to not read mmc dev 1 at boot, because, now it is every time looking for an sd card.
Difficult to say what exactly you did change. However, doing the following should reset the U-Boot environment back to defaults hopefully booting from eMMC again:
Meanwhile, I am still not understanding what exactly it is that you are trying to achieve.
after mmc dev 1
Doing mmc dev 1 just changes the currently selected SDHCI controller instance for any subsequently entered U-Boot commands in that session. It won’t persist or anything.
I booted up my board from SD card properly
But how? What exactly is it that you did?
then I tried to boot it from emmc, to setting my environment default “env default -a”
it booted from emmc, But now mmc dev 1 is not working, it just saves and switches to dev 1 but after resetting it is not booting from SD card.
As mentioned above mmc dev 1 by itself really does not do much of anything.
I really did not understand HOW TO BOOT FROM SD CARD and HOW TO BOOT FROM EMMC
Some more information about Linux booting and various options may be found here:
I want to run my operating system from external SD card or EMMC, how to switch between them when I want, please help me TORADEX…
You may also find this new article about Distro Boot useful: