CL-SOM-AM57x: Linux: Kernel - Revision history

Grinberg: /* Building the kernel */

2017-06-08T13:18:34Z

‎Building the kernel

Show changes

Urim: /* Wifi support */

2016-10-26T08:08:10Z

‎Wifi support

Show changes

Grinberg: /* See also */

2016-05-25T11:53:35Z

‎See also

Urim at 15:31, 18 April 2016

2016-04-18T15:31:17Z

Grinberg: /* TI SDK kernel v4.1.13 */

2016-03-24T16:21:23Z

‎TI SDK kernel v4.1.13

Lifshitz at 13:49, 4 February 2016

2016-02-04T13:49:18Z

Grinberg: /* Device Tree */

2015-12-30T14:09:13Z

‎Device Tree

New page

== Overview ==
Linux kernel for the CompuLab CL-SOM-AM57x System-on-Module / Computer-on-Module provides support for on-board peripherals and abstracts the functionality provided by the hardware.
CompuLab provides ready-to-run binary kernel images, and source code of the modifications and additions made to the Linux kernel to work properly with CL-SOM-AM57x modules.

== Device Tree ==

Device Tree (DT), is a data structure and language for describing hardware. More specifically, it is a description of hardware that is readable by an operating system so that the operating system doesn't need to hard code details of the machine.
A device tree file, named {{filename|*.dts}}, is a text file that describes the hardware platform.
It is compiled into a device tree blob, {{filename|*.dtb}}, which is loaded into memory before the Linux kernel is started.
The Linux kernel then uses that device tree blob to initialize itself at runtime.

CL-SOM-AM57x DT related files are :

* {{filename | arch/arm/boot/dts/am57xx-cl-som-am57x.dts }} - CL-SOM-AM57x core SoM/CoM Device Tree that can be used with almost any base board.
* {{filename | arch/arm/boot/dts/compulab-sb-som.dtsi }} - SB-SOM baseboard Device Tree.
* {{filename | arch/arm/boot/dts/am57xx-sbc-am57x.dts }} - SBC-AM57x single board computer (eval board) Device Tree.

For more details visit official [http://devicetree.org/Device_Tree_Usage Device Tree WiKi] pages and make an overview of a [http://events.linuxfoundation.org/sites/events/files/slides/petazzoni-device-tree-dummies.pdf Device Tree tutorial].

== Building kernel for CL-SOM-AM57x ==
=== Cross-Compiler ===
There are several options for cross-compilation toolchain setup. You can either compile your cross-compiler or use an already built cross-compiler. The cross-compiler should support the ARM embedded-application binary interface ("[http://en.wikipedia.org/wiki/Application_binary_interface#EABI EABI]")
* Pre-built toolchain (recommended):
** [http://www.mentor.com/embedded-software/sourcery-tools/sourcery-codebench/editions/lite-edition/ Sourcery CodeBench Lite]
* Tools for creating cross-compilers:
** [http://crosstool-ng.org/ Crosstool-ng]: Builds a cross-compiler from source. Non-distribution specific.
** [http://www.gentoo.org/proj/en/base/embedded/handbook/index.xml?part=1&chap=4 Crossdev]: Gentoo's cross-compiler builder. Needs Gentoo.

=== Getting kernel sources ===
There are various ways to get Linux kernel sources that can be used as a baseline for CL-SOM-AM57x kernel.
For instance, a copy of linux-stable git tree can be created or a Linux kernel sources snapshot can be downloaded.

Assuming that the {{filename|/home/development/cl-som-am57x/kernel}} directory structure has been created for CL-SOM-AM57x kernel development.

==== Snapshot download ====
* Download [https://www.kernel.org/pub/linux/kernel/v4.x/linux-4.3.tar.gz v4.3] snapshot with a web browser.
* Extract the downloaded archive {{filename|linux-4.3.tar.gz}}
<pre>
cd /home/development/cl-som-am57x/kernel
tar xvf /path/to/downloaded/linux-4.3.tar.gz
mv linux-4.3 linux-cl-som-am57x
</pre>
: This will create {{filename|/home/development/cl-som-am57x/kernel/linux-cl-som-am57x}} directory containing linux kernel tree.
* Apply the CL-SOM-AM57x patch
<pre>
cd /home/development/cl-som-am57x/kernel/cl-som-am57x
patch -p1 < /path/to/cl-som-am57x/kernel/linux-4.3-cl-som-am57x-1.patch
</pre>

==== Git clone ====
* Install [http://git-scm.com/ git] version control system.
* Create a clone of linux kernel tree
<pre>
cd /home/development/cl-som-am57x/kernel
git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git linux-cl-som-am57x
</pre>
* Create a branch for CL-SOM-AM57x development. The CL-SOM-AM57x patches are generated vs. v4.3 tag (d74151c670f51a5d1c7a5aa72dc1f3c0d90fba48 commit) in the Linux tree. It is recommended to use exactly the same baseline to avoid merge conflicts.
<pre>
cd /home/development/cl-som-am57x/kernel/linux-cl-som-am57x
git checkout -b cl-som-am57x-dev v4.3
</pre>
* Apply the CL-SOM-AM57x patch
<pre>
git apply /path/to/cl-som-am57x-linux/kernel/linux-4.3-cl-som-am57x-1.patch
</pre>

{{Note|Future stable kernel versions of 4.3 can also be used by adding the Linux kernel stable repository as a remote and checking out any later tag of the v4.3.y stable kernel branch.}}

=== Building the kernel ===
* Run the following commands:
<pre>
export ARCH=arm
export CROSS_COMPILE=arm-none-linux-eabi-
make sbc-am57x_defconfig && make menuconfig
make && make zImage && make am57xx-sbc-am57x.dtb \
INSTALL_MOD_PATH=/home/development/cl-som-am57x/rootfs make modules_install
</pre>

In the example above:

* The Linux kernel image {{filename|zImage}} will be created in {{filename|/home/development/cl-som-am57x/kernel/linux-cl-som-am57x/arch/arm/boot}}
* The Device Tree binary {{filename|am57xx-sbc-am57x.dtb}} will be created in {{filename|/home/development/cl-som-am57x/kernel/linux-cl-som-am57x/arch/arm/boot/dts}}
* The loadable kernel modules will be installed into the {{filename|/home/development/cl-som-am57x/rootfs/lib/modules}} directory.

When the CL-SOM-AM57x is booted with the kernel image and Device Tree binary created as described above and with networked root filesystem at {{filename|/home/development/cl-som-am57x/rootfs/}}, the system will be able to load the kernel modules properly, thus avoiding module version problems.

== See also ==
* [[CL-SOM-AM57x: Linux: Getting started]]
* [[CL-SOM-AM57x: Linux: Debian]]

[[Category:Linux]]
[[Category:CL-SOM-AM57x]]

@@ Line 24: / Line 24: @@
 <pre>
 cd /home/development/cl-som-am57x/kernel/cl-som-am57x
-patch -p1 < /path/to/cl-som-am57x/kernel/linux-4.4-cl-som-am57x-2.1.patch
+patch -p1 < /path/to/cl-som-am57x/kernel/linux-4.4-cl-som-am57x-3.0.patch
 </pre>
 ===== TI SDK kernel v4.1.13 =====
@@ Line 37: / Line 37: @@
 <pre>
 cd /home/development/cl-som-am57x/kernel/cl-som-am57x-ti
-patch -p1 < /path/to/cl-som-am57x/kernel/ti-sdk-4.1.13/linux-4.1.13-cl-som-am57x-2.1.patch
+patch -p1 < /path/to/cl-som-am57x/kernel/ti-sdk-4.1.13/linux-4.1.13-cl-som-am57x-3.0.patch
 </pre>
 ==== Git clone ====
@@ Line 54: / Line 54: @@
 * Apply the CL-SOM-AM57x patch
 <pre>
-git apply /path/to/cl-som-am57x-linux/kernel/linux-4.4-cl-som-am57x-2.1.patch
+git apply /path/to/cl-som-am57x-linux/kernel/linux-4.4-cl-som-am57x-3.0.patch
 </pre>
@@ Line 72: / Line 72: @@
 * Apply the CL-SOM-AM57x patch
 <pre>
-git apply /path/to/cl-som-am57x-linux/kernel/ti-sdk-4.1.13/linux-4.1.13-cl-som-am57x-2.1.patch
+git apply /path/to/cl-som-am57x-linux/kernel/ti-sdk-4.1.13/linux-4.1.13-cl-som-am57x-3.0.patch
 </pre>

@@ Line 2: / Line 2: @@
 Linux kernel for the CompuLab CL-SOM-AM57x System-on-Module / Computer-on-Module provides support for on-board peripherals and abstracts the functionality provided by the hardware.
 CompuLab provides ready-to-run binary kernel images, and source code of the modifications and additions made to the Linux kernel to work properly with CL-SOM-AM57x modules.
 == Building kernel for CL-SOM-AM57x ==
 === Getting kernel sources ===
@@ Line 34: / Line 12: @@
 ==== Snapshot download ====
 * Download [https://www.kernel.org/pub/linux/kernel/v4.x/linux-4.4.tar.gz v4.4] snapshot with a web browser.
 * Extract the downloaded archive {{filename|linux-4.4.tar.gz}}
@@ Line 45: / Line 24: @@
 <pre>
 cd /home/development/cl-som-am57x/kernel/cl-som-am57x
-patch -p1 < /path/to/cl-som-am57x/kernel/linux-4.4-cl-som-am57x-2.patch
+patch -p1 < /path/to/cl-som-am57x/kernel/linux-4.4-cl-som-am57x-2.1.patch
 </pre>
 ==== Git clone ====
 * Install [http://git-scm.com/ git] version control system.
 * Create a clone of linux kernel tree
 <pre>
@@ Line 55: / Line 47: @@
 git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git linux-cl-som-am57x
 </pre>
-* Create a branch for CL-SOM-AM57x development. The CL-SOM-AM57x patches are generated vs. v4.3 tag (b5be40b90dbaa6bd337f3b77de361bfc0723468b commit) in the Linux tree. It is recommended to use exactly the same baseline to avoid merge conflicts.
+* Create a branch for CL-SOM-AM57x development. The CL-SOM-AM57x patches are generated vs. v4.4 tag (b5be40b90dbaa6bd337f3b77de361bfc0723468b commit) in the Linux tree. It is recommended to use exactly the same baseline to avoid merge conflicts.
 <pre>
 cd /home/development/cl-som-am57x/kernel/linux-cl-som-am57x
@@ Line 62: / Line 54: @@
 * Apply the CL-SOM-AM57x patch
 <pre>
-git apply /path/to/cl-som-am57x-linux/kernel/linux-4.4-cl-som-am57x-2.patch
+git apply /path/to/cl-som-am57x-linux/kernel/linux-4.4-cl-som-am57x-2.1.patch
 </pre>
 {{Note|Future stable kernel versions of 4.4 can also be used by adding the Linux kernel stable repository as a remote and checking out any later tag of the v4.4.y stable kernel branch.}}
 === Building the kernel ===

@@ Line 94: / Line 94: @@
 == See also ==
-* [[CL-SOM-AM57x: Linux: Getting started]]
+* [[CL-SOM-AM57x: Linux: Automatic Installation]]
 * [[CL-SOM-AM57x: Linux: Debian]]
 [[Category:Linux]]
 [[Category:CL-SOM-AM57x]]

@@ Line 34: / Line 34: @@
 ==== Snapshot download ====
-* Download [https://www.kernel.org/pub/linux/kernel/v4.x/linux-4.3.tar.gz v4.3] snapshot with a web browser.
+* Download [https://www.kernel.org/pub/linux/kernel/v4.x/linux-4.4.tar.gz v4.4] snapshot with a web browser.
-* Extract the downloaded archive {{filename|linux-4.3.tar.gz}}
+* Extract the downloaded archive {{filename|linux-4.4.tar.gz}}
 <pre>
 cd /home/development/cl-som-am57x/kernel
-tar xvf /path/to/downloaded/linux-4.3.tar.gz
+tar xvf /path/to/downloaded/linux-4.4.tar.gz
-mv linux-4.3 linux-cl-som-am57x
+mv linux-4.4 linux-cl-som-am57x
 </pre>
 : This will create {{filename|/home/development/cl-som-am57x/kernel/linux-cl-som-am57x}} directory containing linux kernel tree.
@@ Line 45: / Line 45: @@
 <pre>
 cd /home/development/cl-som-am57x/kernel/cl-som-am57x
-patch -p1 < /path/to/cl-som-am57x/kernel/linux-4.3-cl-som-am57x-1.patch
+patch -p1 < /path/to/cl-som-am57x/kernel/linux-4.4-cl-som-am57x-2.patch
 </pre>
@@ Line 55: / Line 55: @@
 git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git linux-cl-som-am57x
 </pre>
-* Create a branch for CL-SOM-AM57x development. The CL-SOM-AM57x patches are generated vs. v4.3 tag (d74151c670f51a5d1c7a5aa72dc1f3c0d90fba48 commit) in the Linux tree. It is recommended to use exactly the same baseline to avoid merge conflicts.
+* Create a branch for CL-SOM-AM57x development. The CL-SOM-AM57x patches are generated vs. v4.3 tag (b5be40b90dbaa6bd337f3b77de361bfc0723468b commit) in the Linux tree. It is recommended to use exactly the same baseline to avoid merge conflicts.
 <pre>
 cd /home/development/cl-som-am57x/kernel/linux-cl-som-am57x
-git checkout -b cl-som-am57x-dev v4.3
+git checkout -b cl-som-am57x-dev v4.4
 </pre>
 * Apply the CL-SOM-AM57x patch
 <pre>
-git apply /path/to/cl-som-am57x-linux/kernel/linux-4.3-cl-som-am57x-1.patch
+git apply /path/to/cl-som-am57x-linux/kernel/linux-4.4-cl-som-am57x-2.patch
 </pre>
-{{Note|Future stable kernel versions of 4.3 can also be used by adding the Linux kernel stable repository as a remote and checking out any later tag of the v4.3.y stable kernel branch.}}
+{{Note|Future stable kernel versions of 4.4 can also be used by adding the Linux kernel stable repository as a remote and checking out any later tag of the v4.4.y stable kernel branch.}}
 === Building the kernel ===
@@ Line 72: / Line 72: @@
 export ARCH=arm
 export CROSS_COMPILE=arm-none-linux-eabi-
-make sbc-am57x_defconfig && make menuconfig
+make cl-som-am57x_defconfig && make menuconfig
 make && make zImage && make am57xx-sbc-am57x.dtb \
       INSTALL_MOD_PATH=/home/development/cl-som-am57x/rootfs make modules_install