when press power button，the red green and blue led is turn on，but serial output nothing，when release power button，no led is turn on and serial output nothing，can bpi-r2 be not powered on？i have not sd card and switch is emmc
Bpi-R2 or Bpi-R2Pro? R2pro imho have no Powerbutton,on r2 you have to press it ~10seconds.
You should see at least bootrom if no bootable device is active. If not check serial connection (rx to tx and tx to rx)
Bpi-R2(MT7623N),No SD card,use usb convert to ttl ,white line connect to tx,green line connect to rx,black line connect to gnd,press powr button 10-15s,nothing is outputed from serial.
Try to swap rx and tx…as i said you should see at least bootrom and get system halt message when there is no bootable system found
These three RGB LED lights will only light up when the power button is pressed, no matter how long the power button is continuously pressed, as long as it is released, it will go out
Yes, the device only stays on if there is a bootable system…but this is decided after bootrom,so you need to load at least bl2 or maybe uboot
How to load BL2 or UBoot? I want him to run openwrt from EMMC instead of SD
You have to boot from sd if emmc is not working and flash emmc…do not forget boot0 partition which is needed to boot from emmc
Now that I have started normally through the SD card, how can I get it to start from EMMC? Do you have a guide for burning OpenWrt to EMMC?
which openwrt have you flashed (mainline or bpi version)? basicly if there is a emmc version flash this to mmcblk0 and the emmc preloader to boot0 and change the partition_config in uboot to that boot0 is enabled
openwrt 18.06，I have compiled and run it on SD, but it’s not how to use EMMC to run it
is this the bpi version of openwrt or the mainline one? maybe it brings some install method in uboot to flash the emmc.
i do not use openwrt so i cannot guide you here completely. bpi-r3 has 2 mmc controllers so it needs to initialize the right rootfs when writing the same image to the other device (e.g. using the sd image on emmc it needs to use the other controller)…mostly this is defined by root param in cmdline (set in uboot) and mounting the right partition as / in linux via fstab
you can boot from emmc after you have written preloader to boot0 of emmc and make it active with “mmc partconf” in uboot
i’ve wrote the manual steps long time ago in my wiki: