I have an issue with Khadas Edge module. When it shipped with Android I’ve flashed the official Ubuntu_lxde_bionic_Linux_4.4 package, but I’ve had some issues with USB Type-C touchscreen and wanted to check Ubuntu_gnome_focal_Linux_5.7. Finally I’ve decided to stay od the Linux 4.4 based Ubuntu and when I’ve burned the image it didn’t want to boot, just the white LED flashes twice and reboots in the loop. I have the HDMI monitor plugged in but nothing there, just detects some signal when module reboots and does’t display anything.
I’ve tried almost every image based od Linux 4.4 and it acts the same. I’ve also tried to burn the images on Windows and on Ubuntu (according to procedure on Kahdas Docs) - no luck.
I think once or twice it did boot right after burning, but when I turned off the module and unplug the power supply, it didn’t boot again and acted like I’ve described above - rebooting in loop with white LED blinking twice every few seconds.
I’ve run Krescue on SD, erased eMMC, reset MCU to factory mode and burned edge-ubuntu-18.04-lxde-linux-4.4-fenix-1.0.11-220430-emmc.raw.img.xz. After reboot I’ve run into problem described in this post:
Do You have some ready solution or just steps written in this thread?
Turns out I can get Linux 4.4 based Ubuntu booted, but only right after burning. When it starts, I can do reboot, shutdown a then turn it on again using power switch and works well, but when I turn it off, unplug the power from the board, it doesn’t boot anymore. What happens when the board loses power supply that may cause such booting problems?
Same thing happens, I’ve erased MMC, flashed this firmware over USB-C, it started normally, but when unplug the power from the board, it can’t boot again. So definitely something wrong happens when the board is unplugged from power source, beacuse everything works fine (shutdowns, reboots) until I unplug the power. Maybe it’s some hardware issue…
I’ve also burned this firmware in SD_USB version to SD card, flashed the 5.x kernel Ubuntu onto MMC, and the 5.x kernel Ubuntu stars normally (even when if I re-plug the power source), but the 4.4 kernel Ubuntu on SD card acts as before. I’ve noticed that uboot manages to start the kernel, but it reboots right after “Starting kernel…” message. Also I’ve checked the partition types, and after burning 4.4 kernel Ubuntu on to MMC, fdisk tool on Krescue doesn’t recognize any of the partitions on MMC - displays “Unknown” type, maybe this is the issue. But after full MMC erase via Krescue it should set up the partitions correctly when burning new image…
Krescue after burning 4.4 Ubuntu image also displays some weird values in partiton type. On 5.x images partition types look fine (like “type=83”), here are some trash instead of correct partition type. That might be the issue. Unfortunately “Erase eMMC FULL” option and burning (either via USB and Krescue) again doesn’t seem to resolve the issue. Pictures below.
@Frank lat question before I decide to send the board back to You for check.
Doing the full eMMC erase i Krescue should wpie everything on the eMMC memory, then using the Krescue Wizard to burn new image should work without no issues right? Even if something is messed up on the memory, that procedure should install new, clean system? Or is there possibility that full erase isn’t quite full and maybe there is some other method to totally wipe the memories and then burn the image?
Ok, I think I’ve solved it, turned out it’s related to power supply. I powered it via DC jack on Captain, now it starts… but there’s another issue related to it - it doesn’t start every time (I mean the board doesn’t power up). When this happens I have to power it via USB-C, then plug the DC jack, unplug the USB-C and it stays powered up. Did You had similar issues with powering with DC jack?
The interesting thing is that really strong USB-C power adapter with PD isn’t enough. I’ve tried few of them because that Was my first idea why it reboots and startup, with no luck.