Monthly Archives: F Y

Cubieboard or other SBC remote control methods

* Serial port
* SSH + X11
* X Protocol

Serial port/UART/RS232

If there isn’t network inside U-Boot boot sequence, of for other reason. Connecting using (replace the x by the corresponding number):
* A serial wire between the controling computer and the controled board (as CubieBoard here) and use the /dev/ttySx port.
* A standard USB< =>serial adapter/wire (as PL2303, CH340, FT2232C… compatible) and use then the /dev/ttyUSBx port.

Connecting serial port on Cubieboard

Connecting serial port on Cubieboard

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Writing traditional mongol with Firefox

Another strangly configured variable in Firefox…
To correctly display vertical traditionnal mongol writing in Firefox, go to the about:config URL, then change the value of the variable to 87 (that’s strangly -1 by default, this is only used for mongol fonts):

gfx.font_rendering.harfbuzz.scripts .

Update:, firefox 29 has 255 instead of -1 (looks like a change in the (computer data type from int to uint)

A specialized javascript site to write traditionnal mongol writing :

Thanks to Ganbold from #linux-sunxi for this tips.

Install Ubuntu-13.10 beta2 ARM on Cubieboard2 from another Cubie ARM system :)

Work in progress: Following this tutorial there is still problem with automatic network dhcp and clock at boot time, until installing a full distro desktop. I still need to find the needed packages to resolve this without installing the full distro

Ubuntu 13.10 Saucy on Cubieboard2

Ubuntu 13.10 Saucy on Cubieboard2

In my case, I start from a previously installed system with u-boot and kernel, this make things easier.
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2D/3D/Video acceleration on cubieboard2 (and MyPaint v1.1 + Wacom数码绘图板)

I managed, this week-end, finally relativly easily to add full hardware acceleration support on Cubieboard2. I used the current stage (beta) of linux-sunxi kernel, and followed step by step kernel compilation tutorial on wiki. I slightly improved documentation, in the case of AllWinner A20.

Focus that created the system image I used to these modification also made an article about this, inspirated by some of my recommandations, and now, The modified image is available from the download area of You can still continue to read this article to understand how to for another distribution. I myself needed to apply some of this rules for my version of (l/x)ubuntu 13.10
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Create aligned disk partitions to improve performances and reduce SSD

Align disk partitions on their cylinders, is, knowing that most frequent datas feet on a cylinder:

* Avoid to read 2 cylinders instead of one => gain time at read, reduce useless cache usage, gain bandewidth.
* Avoid to write 2 cylinders when only one is good enough => gain time, reduce useless cache usage, gain bandwith, reduce wearout
* For the previous reason, allow to grow greatly timelife of an SSD disk (number of writing cycles is limited on an SLC, more on an MLC, even more on a TLC, but the price of this last one is the lower by GB).

A simple method to know if your partitions are well aligned on cylinders

Launch cfdisk on the disk you want to optimize (replace /dev/sda, by the disk to optimize: /dev/sdb, /dev/sdc…):

cfdisk /dev/sda

If you see an asterisk (or star) at the most right of a partition ligne, this one is not aligned on cylinder. In my case, I have to remake all the partitions but sda3:

                           cfdisk (util-linux 2.20.1)

                              Disk Drive: /dev/sda
                       Size: 240057409536 bytes, 240.0 GB
             Heads: 255   Sectors per Track: 63   Cylinders: 29185

    Name        Flags      Part Type  FS Type          [Label]        Size (MB)
                            Pri/Log   Free Space                           1.05*
    sda1        Boot        Primary   ext4                             51158.98*
                            Pri/Log   Free Space                           1.22*
    sda2        Boot        Primary   ext4                             53686.01*
                            Pri/Log   Free Space                           0.41*
    sda3                    Primary   ext4                            135207.16
                            Pri/Log   Free Space                           2.62*

     [   Help   ]  [   New    ]  [  Print   ]  [   Quit   ]  [  Units   ]
     [  Write   ]

                      Create new partition from free space

How to create an unique partition, using the whole disk and well fited

Using the old usagemode of fdisk. I found this tip on an Ubuntu documentation.

Replace /dev/sdX by the disk on which you want to create aligned partition:

fdisk /dev/sdX
[return key]
[return key]
[return key]
[return key]

Et voilà, you will see a beautifull result on cfdisk

To create several aligned partitions: Choose the good option instead of the 4 time [return key] and redo the n (new), for each partition.