Installing Armbian on Vero 4k, does not boot from SD Card

[patientgamer]

Hi, I'm trying to repurpose my Vero 4k (not 4k+) by installing Armbian on it. The device is based on the S905X and it looks like the most recent versions include a dtb for 4k, thanks to the work done by chewitt.

I used the AMLogic s9xx TV Box edition and followed these instructions in the forums to copy the dtb and u-boot.

 

However, I'm having some trouble getting the device to boot into an SD card flashed with the Armbian image. I was wondering whether anyone else has some experience with this.

 

Here's what I tried so far:

1. Downloaded and extracted the image (I used the Minimal/IoT version)
2. Wrote the image to an SD Card (tried two Class 10 ones, 32GB and 64GB). I also tried both dd and USBImager.
3. Mounted the boot partition on my PC
4. Copied u-boot-s905x-s912 to u-boot.ext
5. Edited the extlinux.conf file to use dtb/amlogic/meson-gxl-s905x-vero4k.dtb
6. Inserted the SD card into the Vero 4k slot
7. Used the toothpick method to press the button in the audio jack
8. While keeping the button pressed, attached the PSU cable
9. Waited for the boot process (I tried several durations of pressing the button)

 

I've tried these steps with several variations on u-boot and dtb or other Armbian versions, but in all cases OSMC boots up (installed on emmc)

 

I also successfully ran the OSMC installation from the SD Card a few times, so that suggests the SD Card is fine? I asked on the OSMC forums for help, but got no further than this, so it kinda feels like I ran into a dead end.

 

Any ideas or pointers are much appreciated!

[SteeMan]

The boot process uses the native android uboot on emmc.  I have no idea what uboot OSMC uses and if it is compatible with the mechanism that armbian uses to chain from the native uboot to the u-boot.ext.

To understand what is happening during the boot you will need to hookup a usb-uart connector to the board and capture the uboot output.

[patientgamer]

Thanks for replying! Yes, it seems a bit out of the ordinary (the Vero doesn't come with Android, but with OSMC (Linux) preinstalled). However, I've seen reports of people successfully booting from SD card, so I tried those first, but they didn't seem to have this problem.

 

Would a USB-A to USB-A connector work? Or do I need USB-A to UART? The Vero doesn't have such an external port, so would I need to open it up?

 

It does have a separate USB connector that it can draw power from (without PSU) and connect to a PC.

I failed to mention that I purchased a USB-A to USB-A cable to try this (IIRC this was mentioned somewhere in the OSMC wiki).

Though, when I connect it, it doesn't show up either in lsusb or dmesg. I tried different ports and different PCs. The Vero does boot using this cable, so something is working. Am I missing something maybe?

[SteeMan]

35 minutes ago, patientgamer said:

However, I've seen reports of people successfully booting from SD card

Booting armbian from SD on this box?  Or something else.

The way the armbian build works for these amlogic TV boxes is specifically designed to boot from the android uboot on emmc.

[SteeMan]

38 minutes ago, patientgamer said:

Or do I need USB-A to UART

You we will need to find the debug uart pins on your board, solder connectors to them and connect the usb-uart connector.  Some boards come with pins already soldered in place but most don't.  It can be difficult to sometimes find the right points as they may not be labeled well.

[SteeMan]

46 minutes ago, patientgamer said:

Would a USB-A to USB-A connector work?

No.  USB isn't available as the board is booting.  You need the debug output which early in the boot process is only sent to the debug uart

[patientgamer]

5 hours ago, SteeMan said:

Booting armbian from SD on this box?  Or something else.

It was Armbian on a Vero 4k+ (so not exactly the same as my 4k non plus, but similar).

 

I'll open up the box as soon as I have the time and try to find the UART pins. Do you have any recommendations for a good USB-UART connector?

 

Edited February 10 by patientgamer
typo

[patientgamer]

Actually I just tried, but I can't seem to find any screws on the thing. I naively expected them to be under the bottom pads, or some sticker, but none. I carefully tried to separate the bottom side from the top box, to see if it unclicked or sth, but no dice yet.

[patientgamer]

Well, turns it did unclick after some more attempts. Nothing broke as far as I can see. Here's a picture of the insides: On the top right there's the toothpick button behind the audio jack.

[patientgamer]

I'm a complete noob on this, but I just looked up a tutorial online. Could this be the UART points? If so, that would be a very precise solder job: those dots are about 1mm in diameter.

[SteeMan]

yes those pins should be the debug uart.  I don't have a recommendation on one, but two things to think about, 1) boards will generally either be 3.3v or 5v (so both types exist, although many allow you to switch the voltage with a jumper), if you don't know your voltage start with 3.3v.  Then some boards (Rockchip CPUs have a high baud rate that some adapters don't support), which wouldn't be an issue for this amlogic box, but if you might use it in the future for a rockchip based board you might want to make sure yours is capable of those higher speeds.

[patientgamer]

Thanks for following up and for your advice! I guess I have my work cut out for me. I'll try to find a way to solder those points to a UART connector and report back after.