Failed to boot TX2 from SD Card

I modified the extlinux.conf file in the / boot directory and changed mmcblk0p1 to mmcblk1p1 to try to make TX2 boot from SD card. However, it is found that this does not work. After booting, the system always prompts: swapper / 0 not tainted 4.4.38-tegrea, and it will reboot automatically after 5 seconds, and then it will cycle through this state all the time. Now can’t normal boot, is there a way to return to the original state? Thank you very much!

For rel-32.5, the default sdcard place may not be mmcblk1p1. Thus, please use the part UUID method.

https://elinux.org/Jetson/L4T/Boot_From_External_Device

Hello, I mean, when I modify this configuration file, I can’t start TX2. How can I recover it?

Please directly re-flash it.