Building Linux for A10S from Scratch

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In this post we will explain step by step what you have to do to build the A10S-Debian Linux image and all tools and steps so you can duplicate our image or modify and generate new images which to add support for modules which we didn’t included in our image.

Note that we use Linux-Sunxi github repository to generate the Uboot and Linux kernel. Linux-Sunxi is work in progress  and Linux-Sunxi community is very active, this means every day tens of changes are commited to the repository, unfortunately some of them are not well tested so sometimes things go broken, if you follow the steps below and you get error at some point, just report it to #linux-sunxi irc channel, thing usually get fixed very quickly in matter of hours 🙂

I’ve spoken with hno how to make SNAPSHOT of the current GitHub repository so when git checkout to be sure we use this exactly snapshot which we use to build, but I’m not so good with GitHub and didn’t understood how to use tags, any help is welcome. Anyway latest Linux-Sunxi should be always better and improved (unless something is broken unintentionally 😉 )

1. Setup of the toolchain

You should make sure you have the tools for building the Linux Kernel and install them if you don’t have them. To install new software you should be with super user rights on your Linux machine, so do this type in a terminal.

$ sudo su

you will be asked for your password and then your prompt will change to # which means you are now the super user, all future commands should be run in this mode.

First update apt-get links by typing

# apt-get update

Install the toolchain by typing the following.

# apt-get install gcc-4.6-arm-linux-gnueabi ncurses-dev uboot-mkimage build-essential git

This will install: GCC compiler used to compile the kernal, The kernel config menu
uboot make image which is required to allow the SD card to book into the linux image, Git which allows you to download from the github which holds source code for some of the system, Some other tools for building the kernel

Note that if you use debian may be you will need to add

deb http://www.emdebian.org/debian squeeze main

in the file below:

/etc/apt/sources.list

after the installation you now have all tools to make your very own A10s kernel image!

2. Building Uboot

The Allwinner Linux-Sunxi community uboot is maintained by Henrik Nordstrom aka hno on Freenode irc. You can find him in #linux-sunxi or #olimex channels, if something with uboot is broken he is your man 🙂

First let’s make the directory where we will build the A10S-OLinuXino Linux:

# mkdir a10s_olinuxino 
# cd a10s_olinuxino

Then let’s download the uboot sources from GitHub repository, note there are lot of branches but you have to use sunxi branch.

# git clone -b sunxi https://github.com/linux-sunxi/u-boot-sunxi.git

After the download you should have a new directory

# cd u-boot-sunxi/

With the following command you can start the uboot build:

# make A10s-OLinuXino-M CROSS_COMPILE=arm-linux-gnueabi-

At the end of the process you can check if everything is OK by

# ls u-boot.bin spl/sunxi-spl.bin

If you got these two files everything is complete, well done so far

# cd ..

You should be in the following directory

/home/user/a10s_olinuxino#

3. Building kernel sources for Olinuxino A10S

The Allwinner Linux-Sunxi community Kernel is maintained by Alejandro Mery aka mnemoc on Freenode irc. You can find him in #linux-sunxi or #olimex channel, if something is broken with the Linux Kernel you can contact him or use http://linux-sunxi.org/Mailing_list

Kernel sources for A10s are available on GitHub. You can download them using the following command:

# git clone https://github.com/linux-sunxi/linux-sunxi.git

After the download go to the kernel directory

# cd linux-sunxi/

Here you need from a10s configuration file – a10s_olinuxino_defconfig. The file contains all kernel module settings.

Download a10s_olinuxino_deconfig from https://docs.google.com/file/d/0B-bAEPML8fwldzdkQjJrdW5EU00/edit?usp=sharing

then copy a10s_olinuxino_defconfig file to configs directory:

# cp a10s_olinuxino_defconfig linux-sunxi/arch/arm/configs/.

and make:

# make ARCH=arm a10s_olinuxino_defconfig

update .config file

the above step will generate Linux Kernel with all modules we selected and tested, if you wish to make your changes in the kernel configuration do:

# make ARCH=arm menuconfig

The menuconfig changes a .config text file, which you can view/edit even with a text editor like vi,nano.

With this command you can add or remove different modules for the different peripherials in the kernel. Be careful when use this as this may cause the kernel to not work properly.

You have to patch i2c speed sourses in order to use some of olimex i2c modules on UEXT with software implemented i2C.

The pach change i2c1 and i2c2 speed from 200kHz to 100kHz.

For this purpose use A10S_100kHz_I2C.patch file

Download A10S_100kHz_I2C.patch from https://docs.google.com/file/d/0B-bAEPML8fwlRVRjWE1wdlhxeTQ/edit?usp=sharing

the file has to be copied to and started from arch/arm/plat-sunxi/include/plat/ directory

# cp A10S_100kHz_I2C.patch arch/arm/plat-sunxi/include/plat/
# cd arch/arm/plat-sunxi/include/plat/
# patch -p0 < A10S_100kHz_I2C.patch

the result should be:

patching file i2c.h

Go to linux-sunxi folder

# cd /home/user/a10s_olinuxino/linux-sunxi

Now you can contiue a10s_configuration compiling:

# make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- uImage

when this finish’s you will have uImage ready and you can build the kernel modules:

# make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- INSTALL_MOD_PATH=out modules
# make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- INSTALL_MOD_PATH=out modules_install

DONE! At this point you have uboot and kernel modules.

The uImage file is located in /a10s_olinuxino/linux-sunxi/arch/arm/boot/

The kernel modules are located in

/a10s_olinuxino/linux-sunxi/out/lib/modules/3.x.xx

where 3.x.xx is kernel version

in our case the directory with modules is:

/a10s_olinuxino/linux-sunxi/out/lib/modules/3.0.76+

4. Format and setup the SD-card

We suggest 4GB class 10 micro sd-card but you can use any card between 2GB and 16GB.

First we have to make the correct card partitions, this is done with fdisk.

Plug SD card into your SD card reader and enter in the terminal

# ls /dev/sd

Then press two times <TAB> you will see a list of your sd devices like sda sdb sdc note that some of these devices may be your hard disk so make sure you know which one is your sd card before you proceed as you can damage your HDD if you choose the wrong sd-device. You can do this by unplugging your sd card reader and identify which “sd” devices remove from the list.

Once you know which device is your sdcard like sda use this text instead of the sdX name in the references below:

# fdisk -u=sectors /dev/sdX

then do these steps:

1. p

will list your partitions

if there are already partitions on your card do:

2. d 1

if you have more than one partitition press d while delete them all

3. n p 1

create the first partition, starting from 2048 and ending to 34815

4. beginning 2048 end 34815

create second partition

5. n p 2 enter enter

then list the created partitions:

6. p

if you did everything correctly on 4GB card you should see something like:

Disk /dev/sdX: 3980 MB, 3980394496 bytes
123 heads, 62 sectors/track, 1019 cylinders, total 7774208 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Device Boot Start End Blocks Id System
/dev/sdg1 2048 34815 16384 83 Linux
/dev/sdg2 34816 7774207 3869696 83 Linux

7. w

write changes to sd card

now we have to format the file system on the card:

the first partition should be vfat as this is FS which the Allwinner bootloader understands

# mkfs.vfat /dev/sdX1

the second should be normal Linux EXT3 FS

# mkfs.ext3 /dev/sdX2

5. Debian rootfs

The Linux Kernel and Uboot are ready, now we have need from Linux distribution rootfs.

Basically the only difference between the different Linux distributions is the rootfs, so if you put Debian rootfs you will have Debian, if you put Ubuntu rootfs it will be Ubuntu etc.

How to build one is a long topic, the good thing is that there are many already pre-built so we can just download one and use.

exit the kernel directory

# cd ..

You should be in the directory below

# /home/user/a10s_olinuxino/

download debian rootfs – debian_fs_olimex.tar.gz from https://docs.google.com/file/d/0B-bAEPML8fwlZU9RSmZCdGtwZkk/edit?usp=sharing

mount your sd card EXT3 FS partition:

# mount /dev/sdX2 /mnt
# cd /mnt/

and unarchive the rootfs

# tar -xzvf /home/user/a10s_olinuxino/debian_fs_olimex.tar.gz
# ls

the right result should be:

bin boot dev etc home lib lost+found media mnt opt proc root run sbin selinux srv sys tmp usr var
# cd ..

copy the last generated kernel modules in the new debian file system

cp -rf linux-sunxi/out/lib/modules/3.x.xx+/ /mnt/lib/modules/.

where x.xx is the kernel version
in our case the directory with moduls is:

/a10s_olinuxino/linux-sunxi/out/lib/modules/3.0.76+
# sync
# umount /mnt

at this point you have Debian on your SD card second partition.

6. Write kernel uImage you build to the SD-card

You should be in the directory below

/home/user/a10s_olinuxino#
# mount /dev/sdX1 /mnt/

copy the Kernel uImage to root directory in partition 1

# cp linux-sunxi/arch/arm/boot/uImage /mnt/.

download the a10s_script files from:

https://docs.google.com/file/d/0B-bAEPML8fwlZ0VVWWZjYVZWajQ/edit?usp=sharing

then untar it in /mnt directory

# tar -xzvf a10s_scripts.tar.gz -C /mnt

the a10s_scripts archive contains:

script.bin
script_a10s_linux_LCD_1024x600
script_a10s_linux_LCD_800x480
script_a10s_linux_LCD_480x272
script_a10s_linux_HDMI
back_up

script.bin is a text file with very important configuration parameters like port GPIO assignments, DDR memory parameters, Video resolution etc, by changing these parameters in the script.bin you can configure your Linux without need to re-compile your kernel again and again this is smart way Allwinner provide for tweaking A10s Linux Kernel. The default A10s-olinuxino configuration is made for HDMI output. If you want to switch between HDMI and LCD_1024x600, LCD800x480 or LCD_480x272 mode then you have to replace the existing script.bin file from the first SD card partitition (note that this partitition is FAT – so you can replace the file under Windows or Linux) with the script.bin file from script_a10s_linux_LCD_1024x600, script_a10s_linux_LCD_800x480 or script_a10s_linux_LCD_480x272 directory

write the Uboot and sunxi-spl.bin

Note that you have to write u-boot.bin and sunxi-spl.bin in /dev/sdX (not sdX1 or sdX2)

# dd if=u-boot-sunxi/spl/sunxi-spl.bin of=/dev/sdX bs=1024 seek=8
# dd if=u-boot-sunxi/u-boot.bin of=/dev/sdX bs=1024 seek=32
# sync
# umount /mnt

Now you have an SD card ready to boot debian on A10s-OLinuXino.

Connect USB-SERIAL-CABLE-F to UEXT Tx.Rx and GND, or connect a HDMI screen. Put the SD-card in A10s-OLinuXino and apply +5V power, you should see Uboot and then Kernel messages on the console

default username/password is : root / olimex

7. Simple test of a10s-olinuxino LED1

You can write and read around 25 GPIO on a10s using the file system

root@A10s:~# ls /sys/class/gpio/export

gpio15_pc3/ gpio20_pe2/ gpio26_pe8/ gpio4_pb11/ gpiochip1/gpio10_pb6/ gpio16_pc7/ gpio21_pe3/ gpio27_pe9/ gpio5_pg9/ unexportgpio11_pb7/ gpio17_pc16/ gpio22_pe4/ gpio28_pe10/ gpio6_pg10/gpio12_pb8/ gpio18_pc17/ gpio23_pe5/ gpio29_pe11/ gpio7_pb15/gpio13_pb3/ gpio19_pe1/ gpio24_pe6/ gpio2_pb13/ gpio8_pb16/gpio14_pb4/ gpio1_pb14/ gpio25_pe7/ gpio3_pb12/ gpio9_pb5/

root@A10s:~# ls /sys/class/gpio/

this check available GPIO

the LED1 is connected to PE3(gpio21_pe3).

root@A10s:~# echo out > /sys/class/gpio/gpio21_pe3/direction

make PE3 output

root@A10s:~# echo 1 > /sys/class/gpio/gpio21_pe3/value

write logical 1 in PE3 – turn on LED1

root@A10s:~# echo 0 > /sys/class/gpio/gpio21_pe3/value

write logical 0 in PE3 – turn off LED1

————————————–

EDIT: After some discussion with Henrik on irc channel he made git TAGs on uboot and kernel which snapshot the GitHub repositories to match what I wrote above, this means even there are new changes to the GitHub repositories, if you follow the steps above and something is broken you can do after the # git clone …

for u-boot

# git checkout v2013.07-rc1-sunxi

for kernel

# git checkout sunxi-v3.0.76-r0

these commands will point GitHub to same snapshot we used in the posting to build uboot and kernel

A20-OLinuXino preliminary Debian Linux image

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We have now preliminary Linux Debian image for A20, not all hardware features are completely supported, but for those who are curious to try we upload the image in the WIKI.

1. Installation

Download the image from our Wiki Link, the name is a20_debian_LAN_USB_Cards_LCD_HDMI_SATA_first_preliminaryrelease.rar you have to unpack it. If you are under linux just # dd it to sd card and you are done, do not forget to # sync before you pull the card so all buffers are flushed. If you come from Windows world, use Winrar to unpack then download Win32DiskImager.exe and use it to write the image file to SD-card.

2. Boot

Put the sd card in the card slot and apply power supply, if you have USB-SERIAL-CABLE-F you can see the boot messages, otherwise just wait the Linux to boot, it will take a while.

Note: The default username/password is: root / olimex

In this Debian distribution are installed:

  • xfce4 desktop environment
  • gcc 4.6
  • mplayer

free space on the card: 1.9GB

Note: use at least Class10 card as otherwise the board will work quite slow, the A20-Debian cards we sell pre-loaded are fast Class10 cards.

2. Tested moules with this image

  • USB-ETHERNET-AX88772B
  • MOD-WIFI-RTL8188 
  • A13-LCD 4.3″TS 4.3″ LCD with backlight and touchscreen 480×272 pixels
  • A13-LCD7″TS 7″ LCD with backlight and touchscreen 800×480 pixels
  • A10-LCD10″TS  10.1″ LCD with backlight and touchscreen 1024×600 pixels
  • HDMI
  • Micro SD card
  • SD/MMC card
  • OTG USB
  • HIGH SPEED HOST1 USB
  • HIGH SPEED HOST2 USB
  • ETHERNET 100MBIT
  • SATA
  • Audio IN
  • Audio OUT
  • I2C2(400KHz)

  • I2C1(200KHz)

3. Changing A20-OLinuxino display setings from HDMI mode to LCDXXXxXXX mode

The default SD card setup is made with settings for HDMI 720i/60Hz.

The default SD card setup is made with settings for HDMI 720i/50Hz.
If you want to switch between HDMI 720i/50Hz and LCDXXXxXXX mode then you have to replace the existing script.bin file from the first SD card partitition (note that this partitition is FAT – so you can replace the file under Windows or Linux) with the script.bin file from script_a20_linux_LCD_XXXxXXX_sd directory .

Weekend Programming Challenge Issue-13: ASCII art

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Problem: Convert picture to ASCII art

Make code which converts picture to ASCII art.

Hints: This is very easy challenge although seems hard at first sight. Just convert the picture from color to gray scale, then select font which you will use to print ASCII art and analyze it which letters you could use for gray scale print – every letter have some coefficient of filling from 0 for the space to 255 for solid bar, use letters which are spread well in the font size space. Then slice your image at rectangles with the font size, calculate the median grey scale for each rectangle and print the corresponding ASCII character with same grey scale value.

As test image you can use everything – from Olimex logo to Lena above.

Share your results!

The rules:

You can code the solution in any programming language during the weekend and have to submit it to info@olimex.com latest on Sunday June 2nd.

On Monday we will upload the solutions on GitHub and review https://github.com/OLIMEX/WPC .

You can play with your real name or with nick if you want to be anonymous, we will not disclosure your personal info if you do not want to.

Good Luck and Have fun!

A10S-Debian SD-card stabile image uploaded on Wiki

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A10S now have complete support and the latest stabile image is on our Wiki.

1. Installation

Download the image from our Wiki Link, the name is A10S_debian_GPIO_LAN_USB_SDs_HDMI_LCD_4G_release_2.rar you have to unpack it. If you are under linux just # dd it to sd card and you are done, do not forget to # sync before you pull the card so all buffers are flushed. If you come from Windows world, use Winrar to unpack then download Win32DiskImager.exe and use it to write the image file to SD-card.

2. Boot

Put the sd card in the card slot and apply power supply, if you have USB-SERIAL-CABLE-F you can see the boot messages, otherwise just wait the Linux to boot, it will take a while.

Note: The default username/password is: root / olimex

What you got pre-installed in the image is:

In this Debian distribution are installed:

  • xfce4 desktop environment
  • gcc 4.6
  • python
  • libopencv-dev
  • i2ctools
  • mplayer
  • vlc

free space on the card: 1.9GB

Note: use at least Class10 card as otherwise the board will work quite slow, the A10s-Debian cards we sell preloaded are fast Class10 cards.

2. Tested moules with this image

3. Changing A10S-OLinuxino display setings from HDMI mode to LCDXXXxXXX mode

The default SD card setup is made with settings for HDMI 720i/60Hz.
If you want to switch between HDMI 720i/60Hz and LCDXXXxXXX mode then you have to replace the existing script.bin file from the first SD card partitition (note that this partitition is FAT – so you can replace the file under Windows or Linux) with the script.bin file from script_a10s_linux_LCDXXXxXXX directory.

Remark: UART2 from UEXT connector pin 3 and pin 4 respond to /dev/ttyS1

Minimal Ubuntu 12.04.2 LTS with 3.4.29 kernel image for A13-OLinuXino

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Alex (anubis) posted on our forum that he built minimal Ubuntu image for A13-OLinuXino and hosted it on Gdrive

Features:

  • USB-Ethernet drivers in kernel
  • VGA, LCD support
  • main console on VGA
  • dmesg console on UART1
  • DHCP on eth0 auto
  • ssh server running (just ‘arp -a’ from your host to detect A13’s IP and ssh it to connect)
  • UVC camera support in kernel
  • ready to install x-window-system
  • .config is included (with uImage) to simplify kernel rebuild
  •  /tmp as 16M tmpfs
  • Login/pass:  root/password

based on:

Thanks Alex!

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