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Have you visited the Allwinner Chipset wiki? - http://linux-sunxi.org/


sunxi-media-create.sh

Started by Gary, June 03, 2013, 10:53:53 am

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Gary

Hi Experts,
My cubie doesn't boot from a micro SD image created with the subject script.
Lab Data:


  • cubie board boots Ubuntu fine from berryboot


  • cubie has an hdmi terminal and a usb mouse & keyboard connected


  • cubieboard_hwpack.tar.xz is the hwpack used with the subject script


  • linaro-raring-alip-20130526-380.tar.gz is the rootfs used with the subject script


  • the subject script runs "properly" on a Ubuntu host and displays no errors

  • on boot-up,cubie displays a few lines of text for a brief interval and then displays a blinking cursor


  • after boot-up, the cursor continues to blink and neither mouse nor keyboard activity have any effect on the display


Questions:


  • Are my choices for hwpack and rootfs correct?


  • Should the boot-up messages display on the hdmi terminal?


  • Is my cubie really booting but doesn't display much because of a display compatibility issue?


  • Does the subject script work?


  • What might I by doing wrong?



Thanks everybody,
Gary

patwood

Try ctrl-alt-f1 after it boots to see if you get a text login screen.  If you do, then you probably have an x configuration issue.

Gary

Hi patwood,

  • I noticed the word plymouth on the screen just before cubie became unresponsive to mouse or keyboard

  • Google told me plymouth is a splash screen

  • I followed your idea that it might be an x configuration issue

  • I rebuilt the SD card with the server file system assuming that it doesn't use x

  • Cubie boots up just fine now

  • Strange more people aren't complaining about this. Maybe it's my display. It's a cheapie with a kludge VGA to HDMI converter cable.

  • There's no boot-up display so I'm using the after the fact dmesg.


Will RS232 show the boot-up?

You're the man!
Thanks,
Gary

giovanni.v

Quote from: Gary on June 06, 2013, 04:05:36 pm
Will RS232 show the boot-up?


Depends on the console parameter passed to kernel, look at the boot.scr script in the root of your card to confirm. The boot.scr may look messed... it's because of the uboot header but anyway it is readable.

patwood

The default settings for all the cubieboard distros that I tried (and mk802 and hackberry as well) send boot messages to the serial port.

Note: you should look for both a boot.scr or a uEnv.txt file.  u-boot works with either, but uEnv.txt is easier for humans as you can use a text editor to make changes.  If you have both, remove one, as u-boot will only load one and skip the other.  Can't remember offhand which is loaded first, though.

Gary

Hi All,
If my memory serves me correctly, RS-232 levels are +-6V into a 4K load. The Cubie levels are 0 to 3.3V.  It would seem that a perf board with a Maxim transceiver and a 9 pin D connector would be needed. That being said, for what purpose is the RS232 cable (USB to header) that ships with Cubie?
Thanks,
Gary

patwood

June 07, 2013, 04:41:51 pm #6 Last Edit: June 07, 2013, 04:46:21 pm by patwood
That's because the header is TTL serial, not RS-232 serial.  The Cubieboard ships with a serial<-->USB cable, which works with either +3.3v or +5v serial signals (it uses a transition point of around +2-2.5v).  You are correct that the Cubieboard's serial levels are 0 and +3.3v, and the serial cable that comes with the Cubie works just fine.  Edit: as long as you don't connect the red (+5v) line on the serial cable; this isn't needed as a reference voltage for the serial signals, but it is powered at +5v from the USB line.  Hooking it up to the +5v rail on the cubie *could* damage any component that's not protected from overvoltage.

Gary

patwood et al,
I finally understand the darned cubie RS-232 cable. One end connects to the PC and the other to cubie. What I was missing is the fact that the cable isn't passive. It's active enough to convince the PC it's a USB/RS232 dongle and to handle the cubie signal levels. Thanks for the reminder to not connect 5V.
Gary

patwood

Yeah, there's actually a serial to USB converter chip in the cable's USB plug (amazing what designers can do these days, isn't it).  The drivers for it ship in most modern linux distributions (pl2303.ko), going back to at least Ubuntu 10.04 for me.

bbellido

August 20, 2013, 04:08:09 am #9 Last Edit: August 20, 2013, 04:15:00 am by bbellido
Hello everybody,

I've installed linux, and I need to use de rs-232 on cubieboard directly, the other device I need to connect to cubie is rs-232 compliant, an I'm gonna make a null modem to communicate.

wich is the rs-232 port on cubie to attach? ttyS0? I don't know how I can discover it, I'm using debian (cubieez). I was using a pl2303 conversor (USB to rs-232) and it was attached to ttyUSB0 to connect, but I want to use rs-232 to rs-232 connection directly without conversor.  Any idea? Note: Vcc 3.3 voltios is not a problem for me.

I use python and I connect like this:

ser = serial.Serial('/dev/ttyS1', 19200, timeout=1)

but I don't know wich is the rs-232  '/dev/ttyS1' serial in cubieboard built in

Thanks to all the people who makes this community works and thanks in advance

patwood

There are no rs-232 ports on the cubie.  They are all 3.3V serial. You can't connect an rs-232 port directly to any of the uarts.  What you need is a max232 driver chip like #3 here: http://www.best-microcontroller-projects.com/rs232-work.html

Reread this thread.  The pl2303 is not usb to rs-232.  It's USB to 3.3v serial.