Problem of boot order

I have a custom carrier board with a Xavier NX module (P3668-0000). On this carrier board, I installed an SD receptacle linked to the sdmmc3 interface of the Xavier NX module.
The problem is that, when I trigger the presence of my sd card on sdmmc3, then I can no longer boot on sdmmc4 (sd card of the Xavier NX SOM).
I have three questions :

  1. is the SD card which is on the Xavier NX module (P3668-0000) considered as an SD Card or an emmc?
  2. If it is considered as an SD card … is it possible to scan sdmmc4 before sdmmc3 to boot?
  3. If it is considered an EMMC, then in cbo.dts reverse the order of boot?

They bootloader treats both device as sdmmc. If you think boot order affects you, then please change the boot order in cbo.