Banana pi BPI-M5 How to change default boot device from SD card to EMMC

I don’t know exactly how to change the default boot priority to SD card from EMMC storage.

mmc help from my serial terminal outputs

?       - alias for 'help'
amlmmc  - AMLMMC sub system
autoscr - run script from memory
base    - print or set address offset
bdinfo  - print Board Info structure
bmp     - manipulate BMP image data
boot_cooling- cpu temp-system
booti   - boot arm64 Linux Image image from memory
bootm   - boot application image from memory
bootp   - boot image via network using BOOTP/TFTP protocol
cbusreg - cbus register read/write
cfgload - read 'boot.ini' from FAT partiton
chipid  - Print Chip ID
clkmsr  - Amlogic measure clock
cmp     - memory compare
cp      - memory copy
cramfsload- load binary file from a filesystem image
cramfsls- list files in a directory (default /)
crc32   - checksum calculation
cvbs    - CVBS sub-system
dcache  - enable or disable data cache
defenv_reserv- reserve some specified envs after defaulting env
dhcp    - boot image via network using DHCP/TFTP protocol
echo    - echo args to console
emmc    - EMMC sub system
env     - environment handling commands
exit    - exit script
ext2load- load binary file from a Ext2 filesystem
ext2ls  - list files in a directory (default /)
ext4load- load binary file from a Ext4 filesystem
ext4ls  - list files in a directory (default /)
ext4size- determine a file's size
false   - do nothing, unsuccessfully
fastboot- use USB Fastboot protocol
fatinfo - print information about filesystem
fatload - load binary file from a dos filesystem
fatls   - list files in a directory (default /)
fatsize - determine a file's size
fatwrite- write file into a dos filesystem
fdt     - flattened device tree utility commands
get_rebootmode- get reboot mode
go      - start application at address 'addr'
gpio    - query and control gpio pins
gpt     - GUID Partition Table
guid    - GUID - generate Globally Unique Identifier based on random UUID
hdmitx  - HDMITX sub-system
help    - print command description/usage
i2c     - I2C sub-system
icache  - enable or disable instruction cache
img_osd - image osd sub-system
ini     - parse an ini file in memory and merge the specified section into the env
itest   - return true/false on integer compare
jtagoff - disable jtag
jtagon  - enable jtag
ld_bl40 - load bl40 and run bl40.bin from bl33
load    - load binary file from a filesystem
loadb   - load binary file over serial line (kermit mode)
loadx   - load binary file over serial line (xmodem mode)
loady   - load binary file over serial line (ymodem mode)
loop    - infinite loop on address range
ls      - list files in a directory (default /)
macreg  - ethernet mac register read/write/dump
md      - memory display
mm      - memory modify (auto-incrementing address)
mmc     - MMC sub system
mmcinfo - display MMC info
movi    - Read/write command from/to SD/MMC for ODROID board
mtest   - simple RAM read/write test
mw      - memory write (fill)
mwm     - mw mask function
nm      - memory modify (constant address)
oem     - OEM sub system
open_scp_log- print SCP messgage
osd     - osd sub-system
phyreg  - ethernet phy register read/write/dump
ping    - send ICMP ECHO_REQUEST to network host
printenv- print environment variables
pxe     - commands to get and boot from pxe files
rarpboot- boot image via network using RARP/TFTP protocol
read_temp- cpu temp-system
reboot  - set reboot mode and reboot system
reset   - Perform RESET of the CPU
ringmsr - Amlogic measure ring
rpmb_state- RPMB sub-system
rsvmem  - reserve memory
run     - run commands in an environment variable
saradc  - saradc sub-system
saradc_12bit- saradc sub-system
save    - save file to a filesystem
saveenv - save environment variables to persistent storage
set_trim_base- cpu temp-system
set_usb_boot- set usb boot mode
setenv  - set environment variables
showlogo- Displaying BMP logo file to HDMI screen with the specified resolution
showvar - print local hushshell variables
size    - determine a file's size
sleep   - delay execution for some time
source  - run script from memory
sysboot - command to get and boot from syslinux files
systemoff- system off
tee_log_level- update tee log level
temp_triming- cpu temp-system
test    - minimal test like /bin/sh
tftpboot- boot image via network using TFTP protocol
true    - do nothing, successfully
unzip   - unzip a memory region
usb     - USB sub-system
usbboot - boot from USB device
uuid    - UUID - generate random Universally Unique Identifier
version - print monitor, compiler and linker version
viu_probe- enable viu probe in no secure chip
vout    - VOUT sub-system
vout2   - VOUT2 sub-system
vpp     - vpp sub-system
vpu     - vpu sub-system
write_trim- cpu temp-system
write_version- cpu temp-system

emmc is higher priority than sd by hardware rom, it can’t be changed.