Forum Replies Created
6th March 2017 at 1:48 pm #63700
Could you perhaps share which Debian version you are running and which image is flashed on the Ci20?
The Bluetooth hardware is a bit of a black box basically. The kernel loads the firmware for the chip. And then the interface to the bluetooth chip from the JZ4780 and kernel perspective is a simple UART tx/rx wire. I’m not aware of any kernel configuration options required for Bluetooth audio.
The rest of the Bluetooth stack is in userspace as far as I know. You could check your BlueZ version perhaps. If you are using pulse-audio, perhaps you would need to install pulseaudio-module-bluetooth ?
ZubairLK3rd February 2017 at 9:02 am #63708
Those steps do look sound.
Do you happen to have a serial connection to the board and then look at the log to try to identify where the slowdown happens.
In my experience,
e.g. uboot should appear very quickly.
And tftp kernel should happen quickly as well.
Kernel boot should happen ok as well.
All of the above should take less than 2 minutes.
Initializing a rootfs can take some time and depends on how many services are being initialized and how fast the link is. 10/100 Mbps etc.
What rootfs are you trying to load?
ZubairLK1st February 2017 at 8:36 am #63706
Is everything else use-able and just ssh showing that error?
There could be some corruption in the NAND filesystem.
If you have an SD card handily available, you could reflash the latest Debian image http://www.elinux.org/CI20_Distros#Debian_8_2016-02-02_Beta
ZubairLK1st February 2017 at 8:28 am #63710
Welcome to the forum.
tftpboot happens very quickly whenever I have used it over ethernet.
Could you please share the exact steps you do?
And perhaps share the bootlog via pastebin.com.
ZubairLK12th August 2016 at 11:43 am #63715
Welcome to the forum.
Apologies for the delay as it took a while to come to this issue and investigate.
By default, /dev/random collects entropy from various hardware drivers etc. 
This can be slow. e.g on my desktop xeon. If I do ‘cat /dev/random’ (without rng-tools), it outputs a line and then blocks waiting for more entropy.
Similarly, on the Ci20, if I do a ‘cat /dev/random’ I do see a few characters and then it blocks.
With rng-tools, the desktop /dev/random is superfast. But not on the Ci20.
This can be understood by the fact that basically rng-tools searches for various HW sources of entropy in default places. e.g. /dev/hwrng
So on my desktop, I do see the /dev/hwrng but not on the Ci20. hwrng is ‘H’ard’W’are ‘R’andom ‘N’umber ‘G’enerator. The relevant kernel doc is . So basically the Ci20 would need a hwrng and then a kernel driver exporting it to a dev node /dev/hwrng. After this, rng-tools would be able to work its magic.
There seems to be a hidden HWRNG block inside the JZ4780 SoC. If you search for ‘rng’ in the JZ4780 Programmers manual, you find 2 registers. There has been various amounts of community effort on the driver.  and . But the driver is not in the shipped kernel. The description of those registers is cryptic unfortunately. It looks like one is to enable the hwrng. And the other is a 32 bit register to read the hwrng. I tried using devmem to play with those but couldn’t come up with any conclusive results to share.
Hope this helps
 https://groups.google.com/d/msg/mips-creator-ci20-dev/sFHHUE6-umM/63sdMY4xAgAJ9th June 2016 at 6:06 pm #63733
The Ci20 distros can be a bit platform specific. Debian’s usual wikis for upgrading are more x86 specific.
For the Ci20, I’d recommend upgrading to Debian 8 from here http://elinux.org/CI20_Distros
Then using apt-get install nodejs.
ZubairLK11th May 2016 at 2:29 pm #63757
It might be that password authentication isn’t enabled.
On your ci20, edit the file
sudo nano /etc/ssh/sshd_config
Search for PasswordAuthentication
It should look like this with no # in front to comment it out.
ZubairLK3rd May 2016 at 9:59 am #63766
If you wish to use assembly while running Debian, you can run gcc as etc. natively while running Debian on the Ci20.
If you wish to try bare metal assembly programming without any OS running on the Ci20, you could try checking out the following page
ZubairLK8th April 2016 at 3:03 pm #63769
You could use i2c-tools in Linux. e.g. i2cdetect, i2cset, i2cget, i2cdump
FYI. There is a slight bug in the i2c hardware. The detection isnt fully functional. But if you know something is connected to your bus at a certain address. read/write works.
ZubairLK16th February 2016 at 6:00 pm #63776
We fixed this but haven’t released the kernel yet with the fix.
Still working on it.. Apologies for the delay
ZubairLK15th February 2016 at 4:36 pm #63815
Apologies for the delay. I’ll ask around internally.
ZubairLK15th February 2016 at 4:35 pm #63779
Could you please provide more details..
-Is the Ci20 still accessible via ethernet/ssh?
-Is the display working with other devices correctly?
ZubairLK11th February 2016 at 9:54 am #63781
Thank-you very much for getting back to us.
Its great that you guys managed to get BLE working well on Debian.
The blue-tooth userspace software stack used by Android/Debian might be quite different.
Hence the difference in performance.
ZubairLK22nd January 2016 at 10:54 am #63786
The mplayer code is from Ingenic.
I’m afraid we cannot assist much regarding the video decode on the JZ4780.
ZubairLK22nd January 2016 at 9:46 am #63788
The hardware in the JZ4780 does support VP8 and MPEG4.
However, as I have stated earlier. The mplayer sources are from Ingenic.
We don’t have comprehensive information on what level of support it provides.
Please test it as per your requirements.