Olimex Support Forum

OLinuXino Android / Linux boards and System On Modules => A13 => Topic started by: redfox74 on September 14, 2012, 11:44:01 pm

Title: When will be available linux for A13
Post by: redfox74 on September 14, 2012, 11:44:01 pm
I'm very happy of my A13 , the Android 4.0 work fine but i would test Linux for A13 , that's will be cool for developer. I buy also a Raspberry PI so i can doing some benchmark.
What Linux distribution will be supported ?  With what X11 ?
Best
Roberto
Title: Re: When will be available linux for A13
Post by: weber458 on September 15, 2012, 09:19:07 am
I thing redfox74 you have a point! I have also got those two products and i am really waiting for a linux distro. Android looks really good, ind i spent a lot of nights playng with aps, but linux is linux...
We should also consider that it is a totaly new product and fill ourselves with patience!
Title: Re: When will be available linux for A13
Post by: PeeJay on September 15, 2012, 11:27:13 am
I am going to put Debian or Gentoo on mine. Does anyone know how to install/access the bootloader?
Title: Re: When will be available linux for A13
Post by: olimex on September 15, 2012, 11:32:41 am
there is Linux support at www.linux-sunxi.org

note: use HNO github uboot and amery Linux v3.0 both have install instructions on the Github wiki
we work on document where we will describe the step by step instructions how to build and boot

note: Allwinner officially supports only Android SDK, so the Linux Kernel and Uboot is completely done by the community independant from Allwinner.
A1X developers use #arm-netbook IRC channel to chat you can join there is you have problems.
The Linux is working fine, just the 3d video and GPU code is not open source (ARM restricts Allwinner as all other SoC vendors) so the offorts now are to reverse engineer these and enable in the community made Linux image
Title: Re: When will be available linux for A13
Post by: PeeJay on September 16, 2012, 04:05:31 pm
Ok, I got uBoot running off the SD card but I can't get the kernel to boot. I'll keep trying.
Title: Re: When will be available linux for A13
Post by: olimex on September 16, 2012, 04:18:10 pm
check this https://github.com/hehopmajieh/olinuxino-a13/ (https://github.com/hehopmajieh/olinuxino-a13/)
Title: Re: When will be available linux for A13
Post by: HeHoPMaJIeH on September 17, 2012, 11:05:14 am
Quote from: PeeJay on September 16, 2012, 04:05:31 pm
Ok, I got uBoot running off the SD card but I can't get the kernel to boot. I'll keep trying.

Do you change uBoot settings, especially kernel image location ?
Can you upload kernel error message ?
Title: Re: When will be available linux for A13
Post by: PeeJay on September 18, 2012, 02:06:08 pm
Figured out why the kernel didn't boot - Under system type I had to change the low level uart port to 1.
Now I get this:

Starting kernel ...

<6>Booting Linux on physical CPU 0
<6>Initializing cgroup subsys cpuset
<5>Linux version 3.4.5+ (peejay@ubuntu) (gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5) ) #5 PREEMPT Tue Sep 18 21:00:24 EST 2012
CPU: ARMv7 Processor [413fc082] revision 2 (ARMv7), cr=10c5387d
CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache
Machine: sun5i
DRAM: 512<6>Total Detected Memory: 512MB with 1 banks
<4>Ignoring unrecognised tag 0x00000000
<6>Memory Reserved(in bytes):
<6>     LCD: 0x5a000000, 0x02000000
<6>     SYS: 0x43000000, 0x00010000
<6>     G2D: 0x58000000, 0x01000000
<6>     VE : 0x44000000, 0x05000000
Memory policy: ECC disabled, Data cache writeback
<7>On node 0 totalpages: 114688
<7>free_area_init_node: node 0, pgdat c067f78c, node_mem_map c082d000
<7>  Normal zone: 896 pages used for memmap
<7>  Normal zone: 0 pages reserved
<7>  Normal zone: 113792 pages, LIFO batch:31
<7>pcpu-alloc: s0 r0 d32768 u32768 alloc=1*32768<c>
<7>pcpu-alloc: <c>
Title: Re: When will be available linux for A13
Post by: PeeJay on September 19, 2012, 12:42:06 pm
Quote from: PeeJay on September 18, 2012, 02:06:08 pm
<3>>>> no handle, treat it handle over


That was caused by the serial port driver. I disabled it and now I can boot - but I'm using a usb-serial converter for the console. How do I get the VGA port to work?

Title: Re: When will be available linux for A13
Post by: HeHoPMaJIeH on September 20, 2012, 08:55:08 am
try loading fbcon module. First enable framebuffer terminal support in kernel,




~Best
Title: Re: When will be available linux for A13
Post by: PeeJay on September 20, 2012, 01:48:39 pm
Yes, I did that. The screen just stays in power save mode. It works fine with the preloaded android though.
Title: Re: When will be available linux for A13
Post by: HeHoPMaJIeH on September 20, 2012, 03:00:17 pm
Quote from: PeeJay on September 20, 2012, 01:48:39 pm
Yes, I did that. The screen just stays in power save mode. It works fine with the preloaded android though.

Strange, I use 3.4.5 branch and FB Console works fine, try
cat /dev/urandom > /dev/fb0
Title: Re: When will be available linux for A13
Post by: PeeJay on September 21, 2012, 11:56:09 am
Quote from: HeHoPMaJIeH on September 20, 2012, 03:00:17 pm
Strange, I use 3.4.5 branch and FB Console works fine, try
cat /dev/urandom > /dev/fb0


Nothing. I tried with 3.4.5 and 3.0
Could you post your kernel (uImage) so I can test it?
Title: Re: When will be available linux for A13
Post by: HeHoPMaJIeH on September 21, 2012, 12:21:26 pm
no problem :)
Title: Re: When will be available linux for A13
Post by: vinifr on September 21, 2012, 02:56:08 pm
Hi, HeHoPMaJIeH.

Do you run linux from an sd card or from nand?

Is it possible run linux from nand, overwriting the android?
Title: Re: When will be available linux for A13
Post by: HeHoPMaJIeH on September 23, 2012, 06:32:16 pm
Quote from: PeeJay on September 21, 2012, 11:56:09 am
Quote from: HeHoPMaJIeH on September 20, 2012, 03:00:17 pm
Strange, I use 3.4.5 branch and FB Console works fine, try
cat /dev/urandom > /dev/fb0


Nothing. I tried with 3.4.5 and 3.0
Could you post your kernel (uImage) so I can test it?

Sorry for late reply :
http://31.13.212.1/3.0.42.zip (http://31.13.212.1/3.0.42.zip) this is my kernel image, config and modules
Title: Re: When will be available linux for A13
Post by: HeHoPMaJIeH on September 23, 2012, 06:35:46 pm
Quote from: viniciusfre on September 21, 2012, 02:56:08 pm
Hi, HeHoPMaJIeH.

Do you run linux from an sd card or from nand?

Is it possible run linux from nand, overwriting the android?

Yes it is, you can use nandpart tool from sunxi-tools repo to partition your nand.
P.S You must uses NAND enabled u-boot version or Allwinner's SDK version :)
Title: Re: When will be available linux for A13
Post by: PeeJay on September 24, 2012, 01:43:03 pm
Quote from: HeHoPMaJIeH on September 23, 2012, 06:32:16 pm
Sorry for late reply :
http://31.13.212.1/3.0.42.zip (http://31.13.212.1/3.0.42.zip) this is my kernel image, config and modules


Still didn't work! Is it possible that the version on uboot I'm using is the problem? The one that comes pre-installed has a splash screen, but mine doesn't. I'm using the sunxi branch from https://github.com/hno/uboot-allwinner
Title: Re: When will be available linux for A13
Post by: HeHoPMaJIeH on September 24, 2012, 02:19:48 pm
Quote from: PeeJay on September 24, 2012, 01:43:03 pm
Quote from: HeHoPMaJIeH on September 23, 2012, 06:32:16 pm
Sorry for late reply :
http://31.13.212.1/3.0.42.zip (http://31.13.212.1/3.0.42.zip) this is my kernel image, config and modules


Still didn't work! Is it possible that the version on uboot I'm using is the problem? The one that comes pre-installed has a splash screen, but mine doesn't. I'm using the sunxi branch from https://github.com/hno/uboot-allwinner

Try this http://31.13.212.1/debian_2g.tar.bz2 (http://31.13.212.1/debian_2g.tar.bz2) , debian 2G image, copy it to uSD with DD :
dd if=debian_2g.img of=/dev/sdX, where X is you uSD card.
user: root
pass: password
Title: Re: When will be available linux for A13
Post by: PeeJay on September 24, 2012, 03:27:12 pm
I think I might have figured it out - it's the script.bin file that uboot uses. I tried a different one and now I get occasional flickering on the screen so that's a start. Where does that file actually come from? I can't find one specifically for the A13.
Title: Re: When will be available linux for A13
Post by: HeHoPMaJIeH on September 24, 2012, 05:04:32 pm
Quote from: PeeJay on September 24, 2012, 03:27:12 pm
I think I might have figured it out - it's the script.bin file that uboot uses. I tried a different one and now I get occasional flickering on the screen so that's a start. Where does that file actually come from? I can't find one specifically for the A13.

Try this :
http://31.13.212.1/script.bin (http://31.13.212.1/script.bin)
p.s don't forget to remove script0.bin :)
Title: Re: When will be available linux for A13
Post by: PeeJay on September 25, 2012, 11:08:58 am
That was it, worked first go!! Thanks a lot! ;D ;D
Title: Re: When will be available linux for A13
Post by: HeHoPMaJIeH on September 25, 2012, 11:22:29 am
Quote from: PeeJay on September 25, 2012, 11:08:58 am
That was it, worked first go!! Thanks a lot! ;D ;D

No Problem ;)
Title: Re: When will be available linux for A13
Post by: HeHoPMaJIeH on September 25, 2012, 12:07:37 pm
Quote from: PeeJay on September 25, 2012, 11:08:58 am
That was it, worked first go!! Thanks a lot! ;D ;D

Can you tell me the resolution that you getting from monitor using this config ?
Title: Re: When will be available linux for A13
Post by: PeeJay on September 26, 2012, 11:32:08 am
I think it's 800x480, That's what it is set to in the kernel source.
Title: Re: When will be available linux for A13
Post by: vinifr on September 26, 2012, 11:36:47 pm
What is the file system used in the debian_2g.img?
Title: Re: When will be available linux for A13
Post by: HeHoPMaJIeH on September 27, 2012, 09:44:10 am
Quote from: viniciusfre on September 21, 2012, 02:56:08 pm
Hi, HeHoPMaJIeH.

Do you run linux from an sd card or from nand?

Is it possible run linux from nand, overwriting the android?

hi,
it's possible to run linux from nand. You can download this image :
http://31.13.212.1/sun5i_linux_a13-evb.img (http://31.13.212.1/sun5i_linux_a13-evb.img) and upload it to device with livesuit.
Keep in mind this is testing image :)
user : root
pass : password

Please send some feedback :)
Title: Re: When will be available linux for A13
Post by: vinifr on September 27, 2012, 07:43:48 pm
Quote
Try this http://31.13.212.1/debian_2g.tar.bz2 (http://31.13.212.1/debian_2g.tar.bz2) , debian 2G image, copy it to uSD with DD :
dd if=debian_2g.img of=/dev/sdX, where X is you uSD card.
user: root
pass: password

I am runing linux in sdcard for the time being. But i am trying this image too(sun5i_linux_a13).

I tried to mount debian_2g.img, but I could not. I tried ext3,ext4, ... i got: "bad file system". What is the correct file system this image?
Title: Re: When will be available linux for A13
Post by: jwischka on September 27, 2012, 11:31:05 pm
Quote from: HeHoPMaJIeH on September 27, 2012, 09:44:10 am
Quote from: viniciusfre on September 21, 2012, 02:56:08 pm
Hi, HeHoPMaJIeH.

Do you run linux from an sd card or from nand?

Is it possible run linux from nand, overwriting the android?

hi,
it's possible to run linux from nand. You can download this image :
http://31.13.212.1/sun5i_linux_a13-evb.img (http://31.13.212.1/sun5i_linux_a13-evb.img) and upload it to device with livesuit.
Keep in mind this is testing image :)
user : root
pass : password

Please send some feedback :)


A couple of questions:

1) Does this still require an update to uBoot? If so, is there a pre-built image that's available, as the link on the hno github for pre-builts does not seem to be working.

2) Is there any way to update the uBoot without a UART cable? If I'm reading the instructions on your wiki correctly, it seems as though the answer is no, but I wanted to make sure.

Thanks
Title: Re: When will be available linux for A13
Post by: HeHoPMaJIeH on September 28, 2012, 12:37:12 am
Quote from: viniciusfre on September 27, 2012, 07:43:48 pm
Quote
Try this http://31.13.212.1/debian_2g.tar.bz2 (http://31.13.212.1/debian_2g.tar.bz2) , debian 2G image, copy it to uSD with DD :
dd if=debian_2g.img of=/dev/sdX, where X is you uSD card.
user: root
pass: password

I am runing linux in sdcard for the time being. But i am trying this image too(sun5i_linux_a13).

I tried to mount debian_2g.img, but I could not. I tried ext3,ext4, ... i got: "bad file system". What is the correct file system this image?

This is a RAW image, you can burn it to 2G uSD or you can build your own using instructions provided by hno and amery :)
If you want to resize image mount it in loop device, and use uSD creating instructions
Title: Re: When will be available linux for A13
Post by: HeHoPMaJIeH on September 28, 2012, 12:40:00 am
Quote from: jwischka on September 27, 2012, 11:31:05 pm
Quote from: HeHoPMaJIeH on September 27, 2012, 09:44:10 am
Quote from: viniciusfre on September 21, 2012, 02:56:08 pm
Hi, HeHoPMaJIeH.

Do you run linux from an sd card or from nand?

Is it possible run linux from nand, overwriting the android?

hi,
it's possible to run linux from nand. You can download this image :
http://31.13.212.1/sun5i_linux_a13-evb.img (http://31.13.212.1/sun5i_linux_a13-evb.img) and upload it to device with livesuit.
Keep in mind this is testing image :)
user : root
pass : password

Please send some feedback :)


A couple of questions:

1) Does this still require an update to uBoot? If so, is there a pre-built image that's available, as the link on the hno github for pre-builts does not seem to be working.

2) Is there any way to update the uBoot without a UART cable? If I'm reading the instructions on your wiki correctly, it seems as though the answer is no, but I wanted to make sure.

Thanks

1. No, it's not necessary 
2. Yes you can, using fastboot mode
Title: Re: When will be available linux for A13
Post by: jwischka on September 29, 2012, 06:21:00 pm
Quote from: HeHoPMaJIeH on September 28, 2012, 12:40:00 am
Quote from: jwischka on September 27, 2012, 11:31:05 pm
Quote from: HeHoPMaJIeH on September 27, 2012, 09:44:10 am
Quote from: viniciusfre on September 21, 2012, 02:56:08 pm
Hi, HeHoPMaJIeH.

Do you run linux from an sd card or from nand?

Is it possible run linux from nand, overwriting the android?

hi,
it's possible to run linux from nand. You can download this image :
http://31.13.212.1/sun5i_linux_a13-evb.img (http://31.13.212.1/sun5i_linux_a13-evb.img) and upload it to device with livesuit.
Keep in mind this is testing image :)
user : root
pass : password

Please send some feedback :)


A couple of questions:

1) Does this still require an update to uBoot? If so, is there a pre-built image that's available, as the link on the hno github for pre-builts does not seem to be working.

2) Is there any way to update the uBoot without a UART cable? If I'm reading the instructions on your wiki correctly, it seems as though the answer is no, but I wanted to make sure.

Thanks

1. No, it's not necessary 
2. Yes you can, using fastboot mode


I flashed this image directly to the nand with Livesuit, but it is not booting. The initial Android screen comes up when the board is powered on, and then the screen goes blank. Can you give me any direction as to how to proceed? Do I need to flash a new uBoot, and if so, what is the best way to do that now that I no longer have access to adb?

Thanks!
Title: Re: When will be available linux for A13
Post by: HeHoPMaJIeH on September 29, 2012, 06:28:00 pm
can you paste log messages from debug uart ?
Title: Re: When will be available linux for A13
Post by: jwischka on September 29, 2012, 08:27:35 pm
Quote from: HeHoPMaJIeH on September 29, 2012, 06:28:00 pm
can you paste log messages from debug uart ?


I'll try to dig out a cable and get it hooked up here in a bit. Was hoping to avoid UART if at all possible.
Title: Re: When will be available linux for A13
Post by: jwischka on September 29, 2012, 09:13:10 pm
Quote from: jwischka on September 29, 2012, 08:27:35 pm
Quote from: HeHoPMaJIeH on September 29, 2012, 06:28:00 pm
can you paste log messages from debug uart ?


I'll try to dig out a cable and get it hooked up here in a bit. Was hoping to avoid UART if at all possible.


I'm actually not seeing anything on the UART - which I suspect means i'm doing something wrong. I've opened the COM port in putty, have the proper speeds set, and (think) I have the proper pins hooked up, but I'm not seeing anything at all come across. It could also be that my pin connections aren't that secure (using wires from my UART cable to the board). I'm assuming I should see *something*?
Title: Re: When will be available linux for A13
Post by: PeeJay on September 30, 2012, 03:04:35 pm
I tried to use that disk image today and I had trouble with it as well. uBoot loaded, but there was a crc error with the config file so it used defaults (which was ok anyway). I had to change the partition type to 0x07 for the fat one to get uboot to read the script.bin. The kernel booted, but couldn't detect the filesystem type on mmcblk0p2 so it would just reboot. Running fsck.ext4 fixed that. (It was ext4 right?)
Now it's working, but I've got the most hideous font I've ever seen on the screen!! :o Not sure if it's the kernel or debian, but mine didn't do that. I did select the builtin fonts when compiling the kernel though.
Title: Re: When will be available linux for A13
Post by: PeeJay on September 30, 2012, 03:07:52 pm
Oh, and can you include wpasupplicant in your image!
Title: Re: When will be available linux for A13
Post by: jwischka on September 30, 2012, 03:48:16 pm
Quote from: PeeJay on September 30, 2012, 03:04:35 pm
I tried to use that disk image today and I had trouble with it as well. uBoot loaded, but there was a crc error with the config file so it used defaults (which was ok anyway). I had to change the partition type to 0x07 for the fat one to get uboot to read the script.bin. The kernel booted, but couldn't detect the filesystem type on mmcblk0p2 so it would just reboot. Running fsck.ext4 fixed that. (It was ext4 right?)
Now it's working, but I've got the most hideous font I've ever seen on the screen!! :o Not sure if it's the kernel or debian, but mine didn't do that. I did select the builtin fonts when compiling the kernel though.


Did you do anything (initially) other than flashing the image to nand in livesuit?

Thanks
Title: Re: When will be available linux for A13
Post by: PeeJay on October 01, 2012, 04:18:26 am
Quote from: jwischka on September 30, 2012, 03:48:16 pmDid you do anything (initially) other than flashing the image to nand in livesuit?


I didn't use nand, I put it on a sd card.
Title: Re: When will be available linux for A13
Post by: jwischka on October 01, 2012, 04:19:48 am
Quote from: PeeJay on October 01, 2012, 04:18:26 am
Quote from: jwischka on September 30, 2012, 03:48:16 pmDid you do anything (initially) other than flashing the image to nand in livesuit?


I didn't use nand, I put it on a sd card.


Did you update uBoot before you did it?

Thanks
Title: Re: When will be available linux for A13
Post by: PeeJay on October 01, 2012, 04:34:17 am
Quote from: PeeJay on September 30, 2012, 03:04:35 pmNow it's working, but I've got the most hideous font I've ever seen on the screen!! :o Not sure if it's the kernel or debian, but mine didn't do that. I did select the builtin fonts when compiling the kernel though.


The script.bin file you have included on the disk image seems to be the problem - it uses a much lower screen resolution than the other one you posted at http://31.13.212.1/script.bin.
Title: Re: When will be available linux for A13
Post by: HeHoPMaJIeH on October 01, 2012, 11:28:05 am
Quote from: PeeJay on September 30, 2012, 03:04:35 pm
I tried to use that disk image today and I had trouble with it as well. uBoot loaded, but there was a crc error with the config file so it used defaults (which was ok anyway). I had to change the partition type to 0x07 for the fat one to get uboot to read the script.bin. The kernel booted, but couldn't detect the filesystem type on mmcblk0p2 so it would just reboot. Running fsck.ext4 fixed that. (It was ext4 right?)
Now it's working, but I've got the most hideous font I've ever seen on the screen!! :o Not sure if it's the kernel or debian, but mine didn't do that. I did select the builtin fonts when compiling the kernel though.

It's normal to use default settings :) i forgot to include env definitions :)
Title: Re: When will be available linux for A13
Post by: PeeJay on October 02, 2012, 11:57:12 am
Quote from: jwischka on October 01, 2012, 04:19:48 amDid you update uBoot before you did it?


No, it's included in the image.
Title: Re: When will be available linux for A13
Post by: Srikant on October 16, 2012, 05:21:08 pm
Quote from: HeHoPMaJIeH on September 28, 2012, 12:37:12 am
Quote from: viniciusfre on September 27, 2012, 07:43:48 pm
Quote
Try this http://31.13.212.1/debian_2g.tar.bz2 (http://31.13.212.1/debian_2g.tar.bz2) , debian 2G image, copy it to uSD with DD :
dd if=debian_2g.img of=/dev/sdX, where X is you uSD card.
user: root
pass: password

I am runing linux in sdcard for the time being. But i am trying this image too(sun5i_linux_a13).

I tried to mount debian_2g.img, but I could not. I tried ext3,ext4, ... i got: "bad file system". What is the correct file system this image?

This is a RAW image, you can burn it to 2G uSD or you can build your own using instructions provided by hno and amery :)
If you want to resize image mount it in loop device, and use uSD creating instructions


Hi, thanks for sharing debian image. It worked like a charm. I'm using a13 tablet and surprisingly LCD also worked, but no touch and back light. I installed lxde on it and stuck at login prompt.
I disabled multi touch based on this link (https://www.miniand.com/forums/forums/development/topics/how-do-i-get-the-lcd-display-and-touch-screen-working-on-an-a10-tablet) but no luck, any suggestions?  I also want to know is there any way I can extract uboot and sunxi-spl.bin from sdcard for backup.
Thanks again.
Title: Re: When will be available linux for A13
Post by: HeHoPMaJIeH on October 18, 2012, 10:18:30 pm
Quote from: Srikant on October 16, 2012, 05:21:08 pm
Quote from: HeHoPMaJIeH on September 28, 2012, 12:37:12 am
Quote from: viniciusfre on September 27, 2012, 07:43:48 pm
Quote
Try this http://31.13.212.1/debian_2g.tar.bz2 (http://31.13.212.1/debian_2g.tar.bz2) , debian 2G image, copy it to uSD with DD :
dd if=debian_2g.img of=/dev/sdX, where X is you uSD card.
user: root
pass: password

I am runing linux in sdcard for the time being. But i am trying this image too(sun5i_linux_a13).

I tried to mount debian_2g.img, but I could not. I tried ext3,ext4, ... i got: "bad file system". What is the correct file system this image?

This is a RAW image, you can burn it to 2G uSD or you can build your own using instructions provided by hno and amery :)
If you want to resize image mount it in loop device, and use uSD creating instructions


Hi, thanks for sharing debian image. It worked like a charm. I'm using a13 tablet and surprisingly LCD also worked, but no touch and back light. I installed lxde on it and stuck at login prompt.
I disabled multi touch based on this link (https://www.miniand.com/forums/forums/development/topics/how-do-i-get-the-lcd-display-and-touch-screen-working-on-an-a10-tablet) but no luck, any suggestions?  I also want to know is there any way I can extract uboot and sunxi-spl.bin from sdcard for backup.
Thanks again.

Please tell me what LCD / Touch you are using. SPL and u-boot can be compiled bu source,you don't need to extract it :). Look at olimex.wordpress.com for instructions.
Title: Re: When will be available linux for A13
Post by: Thomas on November 27, 2012, 10:07:16 pm
Quote from: PeeJay on September 19, 2012, 12:42:06 pm
Quote from: PeeJay on September 18, 2012, 02:06:08 pm
<3>>>> no handle, treat it handle over


That was caused by the serial port driver. I disabled it and now I can boot - but I'm using a usb-serial converter for the console. How do I get the VGA port to work?


How did you remove it ? I have the same problem but "lsmod" does not list any serial driver.
Did you use "modprobe -r" or did you put an other kernel on the SD card ?
Title: Re: When will be available linux for A13
Post by: davidefa on December 24, 2012, 04:36:51 pm
To compile 3.4.19 kernel and solve the problem:
Quote<3>>>> no handle, treat it handle over

I had to apply this patch (https://github.com/linux-sunxi/linux-sunxi/commit/18639db64ff6585d4be91f9645674957feb01452)
related to serial driver ( found on this post (https://groups.google.com/forum/#!topic/linux-sunxi/oRf3Hgpx38g) )