A13-SOM-building-latest-Debian

A13_SOM_kernel_3.4.90_building_description

How to make a bootable SD card for A13-OLinuXino-MICRO, A13-SOM-256 and A13-SOM-512 (HYNIX or SAMSUNG RAM memory with kernel 3.4 (and either sunxi or main-line uboot) and Debian file system.

This guide is not suitable for A13-OLinuXino and A13-OLinuXino-WIFI.

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1. Setup of the toolchain


You should make sure you have the software tools required for building the Linux Kernel. Please install the required tools if you don't have them already. To install new software you should be logged as a super user on your Linux machine; the first thing to do would be to type in the 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.

At this point update apt-get links by typing

apt-get update

Install the toolchain by typing the following.

apt-get install gcc-4.7-arm-linux-gnueabihf ncurses-dev uboot-mkimage build-essential git

This will install: GCC compiler used to compile the kernel; the kernel config menu uboot creates image which is required to allow the SD card to boot into the linux image; Git which allows you to download from the github which holds source code for some of the system; additional 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 A13 kernel image!

2. Building Uboot


Here you have two options. The first is to use sunxi u-boot and the second is to use mainline u-boot. The sunxi u-boot is suitable for the boards that have HYNIX DDR3 chip - H5TQ2G83CFR. The mainline u-boot is suitable for boards that have SAMSUNG DDR3 chip - K4B2G0846Q. Note that if you use the sunxi u-boot with SAMSUNG DDR3 memory then you would have different problems because the new SAMSUNG DDR chip is not supported in this u-boot. The mainline u-boot will be suitable for HYNIX and SAMSUNG DDR3.

First let's make the directory where we will build the A13-OLinuXino-Micro/SOM linux:

mkdir a13-micro-SOM-kernel_3.4
cd a13-micro-SOM-kernel_3.4

After that follow either chapter 2.1 or 2.2 (2.1 is suitable for sunxi u-boot and XYNIX RAM memory; 2.2 is suitable for mainline u-boot and SAMSUNG RAM memory)

2.1. Building sunxi u-boot If we have a board with HYNIX RAM let's download the uboot sources from GitHub repository, note that there are lot of branches but you have to use sunxi branch. Note that the u-boot for A13-OLinuXino-MICRO and A13-SOM boards is tested with the next branch:

git rev-parse --verify HEAD 78592f1d95cccf329ed515a176c80be5c87827a0

this means after you have download the sources (with git clone) you can switch to the exact commit with:

git reset --hard 78592f1d95cccf329ed515a176c80be5c87827a0

Download u-boot sources:

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/

Note that there are 2 versions of A13-SOM boards:

-A13-SOM with 256MB DDR3 memory size -A13-SOM with 512MB DDR3 memory size - need u-boot patch

If you have A13-SOM board with 512MB memory size then first you have to allpy patch for changing DDR3 memory size: download u-boot_A13_SOM_512MB.patch using wget command

wget "https://drive.google.com/uc?export=download&id=0BwplT87k9SCgY3lIWVlLd3ZlSEk"

and patch the file board/sunxi/dram_a13_oli_micro.c with the next command

patch -p0 < u-boot_A13_SOM_512MB.patch

If you have A13-SOM with 256MB memory size you no need from patch. By default u-boot settings are set for 256MB memory size and you can start building imediately after download u-boot.

You can start uboot building with the next commands:

make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- A13-OLinuXinoM_config
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf-

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

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

spl/sunxi-spl.bin u-boot.bin u-boot-sunxi-with-spl.bin

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

cd ..

You should be in the following directory

/home/user/a13-micro-SOM-kernel_3.4#

At this point skip 2.2 directly to chapter 3.

2.2. Building mainline u-boot


Download u-boot sources:

git clone git://git.denx.de/u-boot.git

After the download you should have a new directory

cd u-boot

If we have a board with SAMSUNG RAM let's download the uboot sources from GitHub repository, note that the u-boot for A13-OLinuXino-MICRO and A13-SOM boards is tested with the next branch:

git rev-parse --verify HEAD 1733259d25015c28c47990ec11af99b3f62f811c

this means after you have download the sources you can switch to the exact commit with

git reset --hard 1733259d25015c28c47990ec11af99b3f62f811c

Load the configuration file. It is tha same for A13-SOM and A13-Micro board

make CROSS_COMPILE=arm-linux-gnueabihf- A13-OLinuXinoM_defconfig

you can configure some u-boot settings like DDR3 settings, clocks and other with:

make menuconfig

It is recommended to choose:

[*]Enable workaround for booting old kernels

the board has stable behaviour with [360] sunxi dram clock speed [100] sunxi mbus clock speed

but you can choose other settings depending from your application

save it the settings and exit

Compile the u-boot

make CROSS_COMPILE=arm-linux-gnueabihf-

When the compilation completes, there will be u-boot-sunxi-with-spl.bin available in your u-boot tree.

Now you have to create a new boot.cmd file with the following contain

setenv bootm_boot_mode sec
setenv bootargs console=ttyS0,115200 root=/dev/mmcblk0p2 rootwait panic=10
load mmc 0:1 0x43000000 script.bin || load mmc 0:1 0x43000000 boot/script.bin
load mmc 0:1 0x42000000 uImage || load mmc 0:1 0x42000000 boot/uImage
bootm 0x42000000

convert boot.cmd in boot.scr with the next command

mkimage -C none -A arm -T script -d boot.cmd boot.scr

The result should be a new boot.scr file that you have to copy to the first SD card partition (where uImage and script.bin file are located).

3. Building kernel sources for A13-SOM


Kernel sources for A13 are available on GitHub. Note that the following building is made with the revision below:

git rev-parse --verify HEAD e37d760b363888f3a65cd6455c99a75cac70a7b8

You can download the kernel sources using the following command:

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

After the download go to the kernel directory

cd linux-sunxi/

Note that before compiling kernel you have to do a patch kernel in order to change I2C sped from 200kHz to 100kHz (need for Olimex's I2C modules) and some other changes related with missing power management with AXP209 chip.

download the patch a13_micro_SOM.patch using wget command

wget "https://drive.google.com/uc?export=download&id=0BwplT87k9SCgQ0IxZjRtaHVnMzg"

and apply the patch:

patch -p1 < a13_micro_SOM.patch

The next step is to configure the system

Here you need from a13 configuration file - a13_micro_SOM_defconfig. The file contains all kernel module settings.

Download a13_micro_SOM_defconfig using wget command

wget "https://drive.google.com/uc?export=download&id=0BwplT87k9SCgWEdqRGl2amxyd2c"

then copy a13_micro_SOM_defconfig file to configs directory:

cp a13_micro_SOM_defconfig /arch/arm/configs/

and make:

make ARCH=arm a13_micro_SOM_defconfig

The result should be: configuration written to .config

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 peripherals in the kernel. Be careful when use this as this may cause the kernel to not work properly.

Now you can continue with kernel image compiling

make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- -j4 uImage

when this finish you will have uImage ready and the result should be:

Kernel: arch/arm/boot/Image is ready LD arch/arm/boot/compressed/vmlinux OBJCOPY arch/arm/boot/zImage Kernel: arch/arm/boot/zImage is ready UIMAGE arch/arm/boot/uImage Image Name: Linux-3.4.79+ Created: Mon May 12 09:22:56 2014 Image Type: ARM Linux Kernel Image (uncompressed) Data Size: 4612216 Bytes = 4504.12 kB = 4.40 MB Load Address: 40008000 Entry Point: 40008000 Image arch/arm/boot/uImage is ready

Now you can build the kernel modules:

make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- -j4 INSTALL_MOD_PATH=out modules
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- -j4 INSTALL_MOD_PATH=out modules_install

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

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

The kernel modules are located in

linux-sunxi/out/lib/modules/3.x.xx where 3.x.xx is kernel version

in our case the directory with modules is:

linux-sunxi/out/lib/modules/3.4.90+

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 of the ?sd? devices disappears 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 /dev/sdX

then do these steps:

1. p will list your partitions

if there are already partitions on your card do:

2. d enter 1 if you have more than one partition press d while delete them all

3. create the first partition, starting from 2048 n enter p enter 1 enter enter +16M

4. create second partition n enter p enter 2 enter enter enter

then list the created partitions: p enter if you did everything correctly on 4GB card you should see something like:

Disk /dev/sdg: 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. Write the Uboot and sunxi-spl.bin


You should be in /home/user/a13-micro-SOM-kernel_3.4# directory Note that you have to write u-boot-sunxi-with-spl.bin in /dev/sdX (not sdX1 or sdX2)

dd if=u-boot-sunxi/u-boot-sunxi-with-spl.bin of=/dev/sdX bs=1024 seek=8

Note that if you use mainline u-boot then you have to copy the generated boot.scr file in the first sdcard partition. For example:

mkdir /mnt/sd
mount /dev/sdX1 /mnt/sd
cp /u-boot/boot.scr /mnt/sd/ 

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


copy the Kernel uImage to root directory in partition 1

cp linux-sunxi/arch/arm/boot/uImage /mnt/sd

7. Write script.bin file


script.bin is a file with very important configuration parameters like port GPIO assignments, DDR memory parameters, Video resolution etc, download the script.bin using wget command

wget "https://drive.google.com/uc?export=download&id=0BwplT87k9SCgYXhpQ2djd2hZRDg"
cp script.bin /mnt/sd
sync
umount /dev/sdX1

8. 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/a13-micro-SOM-kernel_3.4

download the torrent of the archive with debian rootfs - a13_micro_SOM_debian_FS.tgz using wget command

wget https://www.olimex.com/wiki/images/1/18/A13_micro_SOM_debian_FS.torrent

Launch a torrent client and download the file.

mount your sd card EXT3 FS partition:

mount /dev/sdX2 /mnt/sd

and unarchive the rootfs

tar xzvf a13_micro_SOM_debian_FS.tgz -C /mnt/sd
ls /mnt/sd

the right result should be: bin dev home lost+found mnt proc run selinux sys usr boot etc lib media opt root sbin srv tmp var

Now you have to replace the new generated kernel modules from /home/user/a13-micro-SOM-kernel_3.4linux-sunxi/out/lib/modules/ to the new debian file system

rm -rf /mnt/sd/lib/modules/*
cp -rfv linux-sunxi/out/lib/modules/3.x.xx+/ /mnt/sd/lib/modules/

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

cp -rfv linux-sunxi/out/lib/modules/3.4.90+/ /mnt/sd/lib/modules/

replace /lib/firmware folder with the generated /linux-sunxi/out/firmware

rm -rf /mnt/sd/lib/firmware/
cp -rfv linux-sunxi/out/lib/firmware/ /mnt/sd/lib/
sync
umount /mnt/sdX2

At this point you have Debian on your SD card second partition and you have an SD card ready to boot debian on A13-OLinuXino-Micro/SOM

Connect USB-SERIAL-CABLE-F to UEXT Tx.Rx and GND, or connect a HDMI screen. Put the SD-card in A13-OLinuXino-Micro/SOM and apply 6-16V power, you should see Uboot and then Kernel messages on the console

default username/password is : root / olimex