<command> <interface> [devnum][.hwpartnum][:partnum|#partname]

Many U-Boot commands allow specifying partitions (or whole disks) using a generic syntax.

interface

The interface used to access the partition's device, like mmc or scsi. For a full list of supported interfaces, consult the uclass_idname_str array in drivers/block/blk-uclass.c

devnum

The device number. This defaults to 0.

hwpartnum

The hardware partition number. All devices have at least one hardware partition. On most devices, hardware partition 0 specifies the whole device. On eMMC devices, hardware partition 0 is the user partition, hardware partitions 1 and 2 are the boot partitions, hardware partition 3 is the RPMB partition, and further partitions are general-purpose user-created partitions. The default hardware partition number is 0.

partnum

The partition number, starting from 1. The partition number 0 specifies that the whole device is to be used as one "partition."

partname

The partition name. This is the partition label for GPT partitions. For MBR partitions, the following syntax is used:

<devtype><devletter><partnum>

devtype

The devtype field is set in dependence of the device class:

devtype	device class
hd	IDE or SATA
sd	SCSI
usbd	USB
mmcsd	eMMC or SD-card
xx	others

See the part_set_generic_name function in disk/part.c for the complete list.

devletter

The device number as an offset from a. For example, device number 2 would have a device letter of c.

partnum

The partition number. This is the same as above.

If neither partname nor partnum is specified and there is a partition table, then partition 1 is used. If there is no partition table, then the whole device is used as one "partition." If none of devnum, hwpartnum, partnum, or partname is specified, or only - is specified, then devnum defaults to the value of the bootdevice environmental variable.

List the root directory contents on MMC device 2, hardware partition 1, and partition number 3:

ls mmc 2.1:3 /

Load /kernel.itb to address 0x80000000 from SCSI device 0, hardware partition 0, and the partition labeled boot:

load scsi #boot 0x80000000 /kernel.itb

Print the partition UUID of the SATA device $bootdevice, hardware partition 0, and partition number 0:

part uuid sata -