boot_order DEVICE...
Set OMAP warm boot order of up to four devices. Each device can be one of: xip xipwait nand onenand mmc1 mmc2_1 mmc2_2 uart usb_1 usb_ulpi usb_2
3.2.2. boot - boot from script, device, …
3.2.4. bootm - boot an application image