cannot boot successfuly with official Debian image

[jmss]

Hi,

I'm using the official Debian image from https://docs.google.com/file/d/0B-bAEPML8fwleDJMaG5reWZZeDQ/edit?usp=sharing

This image seems to boot, but there must be a problem with my monitor connected with HDMI.

It looks like the software is trying to display something but the monitor is not able to do so. I can only see for a fraction of a second a message, almost impossible to read, like "out of sync" or something like that.

So, it seems the default HDMI configuration is no good for this monitor (HP W2070a, http://goo.gl/1ejBFk).

Do I need to change the default resolution? If so, how can I do that if I can't use the display? Can I do it in the SD card in another computer?

Thanks.

[olimex]

use serial cable connected to the console

[jmss]

use serial cable connected to the console

Thanks for the suggestion. Unfortunately I don't have a serial cable. Yet.

Meanwhile, I've been trying to modify script.bin with sunxi-tools (bin2fex, fex2bin):

  screen0_output_type = 3
  screen0_output_mode = 5

I've tried modes:

  2    480p    1360*768
  3    576p    1280*1024
  4    720p50    1024*768

with similar results as the default mode 5.

Some weeks ago I was able to use the unofficial Arch Linux image, so there must be something different with it.

Anyway: can I login with SSH with the monitor disconnected?

[jmss]

Some weeks ago I was able to use the unofficial Arch Linux image, so there must be something different with it.

Clarification: I just tested Arch Linux again (https://www.olimex.com/forum/index.php?topic=1856.0) and it can't also work with the display, but I can login with SSH.

[jmss]

Unfortunately Arch Linux does not have the change_display.sh script.

Another curious fact is that 720p60 is in fact supported by the monitor:

Resolutions supported
1600 x 900 @60 Hz, 1440 x 900 @ 60 Hz, 1280 x 1024 @ 60 Hz, 1280 x 720 @ 60 Hz, 1024 x 768 @ 60 Hz,
800 x 600 @ 60 Hz, 720 x 400 @ 70 Hz, 640 x 480 @ 60 Hz

With a digital camera, I recorded a movie and by watching frame by frame I was able to read the message which is quickly shown in the monitor: input signal out of range, change settings to 1600?900 60Hz.

[progmetalbg]

Well, I used the official fex file for A20-OLinuXino-MICRO provided by the Sunxi community in my Arch Linux image:
https://github.com/linux-sunxi/sunxi-boards/blob/master/sys_config/a20/a20-olinuxino_micro.fex
I'm still running my board headless, so I have no experience with the HDMI output.
However, you can check this page in the linux-sunxi site:
http://linux-sunxi.org/Display#HDMI
and ask for help in IRC channel: http://webchat.freenode.net/?channels=linux-sunxi
You can also try to upload different script.bin files generated by you via SSH (scp) in /boot partition in Arch and reboot board to see if they work.

[progmetalbg]

An addition to my previous post.
This HP monitor W2072a only have DVI-D and VGA according to specifications and this seems to be the root cause of your problems. I suppose you use HDMI to DVI cable.
So you'd better not experiment with script.bin and try changing kernel arguments.
Example for the Arch image:

1. Install u-boot tools package

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pacman -Sy uboot-mkimage
2. Switch to /boot directory

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cd /boot
3. Create boot.cmd file:

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cat > boot.cmd <<END
setenv bootargs console=ttyS0,115200 disp.screen0_output_mode=1280x720p60 root=/dev/mmcblk0p1 rootwait panic=10
ext2load mmc 0 0x43000000 script.bin
ext2load mmc 0 0x48000000 uImage
bootm 0x48000000
END
4. Create u-boot boot.scr file:

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mkimage -C none -A arm -T script -d boot.cmd boot.scr
5. Reboot

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shutdown -r now

Repeat steps 2-5 with different disp.screen0_output_mode resolution/refresh rate if it doesn't work.
Ask in linux-sunxi IRC for help if this guide does not help.

[jmss]

Thanks.

You're right about the monitor inputs. That fact was lingering in my subconscious.

With your instructions I was able to change to the recommended resolution 1600x900@60. However, the monitor keeps alternating between dark black (like if off) and flickering bright black (like if sleeping). Looks like several display modes are being tried (?)

There are no relevant messages in dmesg or journalctl, which suggests a pure hardware connection problem (?)

I will try the IRC.

[progmetalbg]

You can try different options in the setenv bootargs line in boot.cmd

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setenv bootargs console=tty0 disp.screen0_output_mode=EDID:1280x720p60 root=/dev/mmcblk0p1 rootwait panic=10

EDID might help http://en.wikipedia.org/wiki/EDID
Setting console=tty0 is also better than ttyS0 when you don't have FTDI cable for debug.
Don't forget to run mkimage and reboot after every change in boot.cmd
You can see you kernel arguments list when you boot with (to check if you are doing the previous steps right):

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cat /proc/cmdline

[jmss]

I've tried tty0 and EDID to no avail.

No luck in IRC either, they are talking about other stuff ;P

Is there an official support contact?

[jmss]

For accessing the A20 through SSH I had to change /etc/network/interfaces from:

#auto eth0
iface eth0 inet dhcp

to:

auto eth0
iface eth0 inet dhcp