Rockchip/Uboot goes to loader mode or Maskrom_rockusb 0 mmc

1. Rockchip/Uboot goes to loader mode

=> rockusb
rockusb - Use the rockusb Protocol

Usage:
rockusb <USB_controller> <devtype> <dev[:part]>  e.g. rockusb 0 mmc 0

=> rockusb  0  mmc  0
RKUSB: LUN 0, dev 0, hwpart 0, sector 0x0, count 0x1d1f000
\DDR Version 1.22 20190506
In
soft reset
SRX
 

2. maskrom 

nanopi4#  rbrom
DDR Version 1.24 20191016
In
soft reset
SRX
Channel 0: DDR3, 800MHz
Bus Width=32 Col=10 Bank=8 Row=15 CS=1 Die Bus-Width=16 Size=1024MB
Channel 1: DDR3, 800MHz
Bus Width=32 Col=10 Bank=8 Row=15 CS=1 Die Bus-Width=16 Size=1024MB
256B stride
ch 0 ddrconfig = 0x101, ddrsize = 0x20
ch 1 ddrconfig = 0x101, ddrsize = 0x20
pmugrf_os_reg[2] = 0x32817281, stride = 0x9
OUT
Boot1 Release Time: Jun  2 2020 15:02:17, version: 1.26
CPUId = 0x0
SdmmcInit=2 0
BootCapSize=100000
UserCapSize=7456MB
FwPartOffset=2000 , 100000
##############serialno_str = 0UQMAKIBII
UsbBoot ...72564
powerOn 84831