To create boot device alias

Step 1: ok probe-scsi-all

Step 2: ok show-disks

Step 3: Set boot-device

Method 1: OBP

ok nvalias  

   eg.
   ok nvalias disk2 /iommu@f,e0000000/sbus@f,e0001000/esp@f,800000/sd@3,0:a
   ok nvalias disk2 /pci@1f,0/pci@1/scsi@3,1/disk@3,0

ok setenv boot-device disk2

ok reset

Method 2: nvedit

ok nvedit

0: devalias disk2 /iommu@f,e0000000/sbus@f,e0001000/esp@f,800000/sd@3,0:a

^c (control c)

ok nvstore

ok setenv use-nvramrc? true

ok reset

Method 3: Using the existing device alias

ok devalias

ok setenv boot-device 

ok printenv boot-device

ok reset