Can I start up from USBSSD even after updating Jetson to Jetpack 3.1?

I recently updated Jetpack from 3.0 to 3.1.
However, when it was 3.0, it was able to start from USBSSD, but it became impossible after 3.1.

The setting(extlinunx.conf) is as follows

DEFAULT usbssd

MENU TITLE p 2371 - 2180 eMMC boot options

LABEL primary
MENU LABEL primary kernel
LINUX / boot / Image
INITRD / boot / initrd
APPEND $ {cbootargs} root = / dev / mmcblk 0 p 1 rw rootwait

LABEL usbssd
LINUX / boot / Image
INITRD / boot / initrd
APPEND $ {cbootargs} root = / dev / sda 1 rw rootwait

I could not do it. Is there any other way?

Is there really a space in “/ dev / sda 1”? I assume this was written this way due to forum interfering with this, though highlighting the code and clicking on the icon in the “Add Reply” (at upper right tool bar) “</>” would get around that.

I have not tried booting with USB SATA, in theory it would work if the Linux side stays at USB2 when it transfers from U-Boot to the Linux kernel. If the root partition runs on a USB controller which has to reset during transfer from U-Boot to kernel it would cause the partition to be lost. So while you are in a normal boot, and you run “lsusb -t”, how does the speed of the root_hub show? Is it 480M or 5000M? If 5000M this would cause a failure since U-Boot runs at 480M speed.