Ilya: /* Getting kernel sources */

2015-07-14T11:56:37Z

‎Getting kernel sources

Ilya: /* Overview */

2014-05-01T12:18:12Z

‎Overview

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Ilya: /* Getting kernel sources */

2013-12-26T11:27:42Z

‎Getting kernel sources

Grinberg: /* See also */

2013-09-09T10:11:36Z

‎See also

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== Overview ==
Linux kernel supplied with the [http://compulab.co.il/products/computer-on-modules/cm-t335/#devres CM-T335 Android Demo package] provides support for the on-board peripherals and abstracts the functionality provided by the hardware.
Current support coverage is specified on the [http://compulab.co.il/availability-of-os-and-drivers-for-cm-t335-and-sbc-t335/ O/S support coverage map] page.
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 CM-T335 modules.
The kernel binary is optimized for using with Android, however can be used with any Linux ARM compatible distribution as well.

== Building kernel for CM-T335 ==
In this article we assume that the {{filename|/home/development/cm-t335/android}} directory is used for CM-T335 kernel development.

=== Getting cross-compiler ===
The recommended pre-built toolchain repository is hosted on the [http://gitorious.org/rowboat/prebuilts-gcc-linux-x86-arm-arm-eabi-4_6 Rowboat Gitorious] website.
* Clone the toolchain repository. By default it will be created in the directory named {{filename|prebuilts-gcc-linux-x86-arm-arm-eabi-4_6/}}.
<pre>
cd /home/development/cm-t335/android
git clone -b rowboat-jb git://gitorious.org/rowboat/prebuilts-gcc-linux-x86-arm-arm-eabi-4_6.git
</pre>

=== Getting kernel sources ===
The Rowboat Kernel sources repository is hosted on the [http://gitorious.org/rowboat/kernel Rowboat Gitorious] website.
* Clone the kernel sources repository. By default it will be created in the directory named {{filename|kernel/}}.
<pre>
cd /home/development/cm-t335/android
git clone git://gitorious.org/rowboat/kernel.git
</pre>
* Create a branch for CM-T335 development. The CM-T335 patches are generated vs. [http://gitorious.org/rowboat/kernel/commit/996686459db1181a5deaf5d493681ecb5bf43ad7 rowboat-jb-am335x-4.1.2] tag (996686459db1181a5deaf5d493681ecb5bf43ad7 commit) in the Rowboat kernel tree. It is recommended to use exactly the same baseline to avoid merge conflicts:
<pre>
git checkout -b cm-t335-dev rowboat-jb-am335x-4.1.2
</pre>
* Apply the CM-T335 patch:
<pre>
cd /home/development/cm-t335/android/kernel
git apply /path/to/cm-t335-android/kernel/linux-3.2.0-cm-t335-1.patch
</pre>

=== Building the kernel ===
* Setup the toolchain
<pre>
export PATH=/patch/to/cross/compiler/prebuilts/gcc/linux-x86/arm/arm-eabi-4.6:$PATH
export ARCH=arm
export CROSS_COMPILE=arm-eabi-
</pre>
* Build the kernel
<pre>
cd /home/development/cm-t335/android/kernel
make cm_t335_android_defconfig
make menuconfig
make uImage
</pre>

In the example above, the Linux kernel image ({{filename|uImage}}) will be created in {{filename|/home/development/cm-t335/android/kernel/arch/arm/boot}} directory.
{{Note|There is no need to build and install any kernel modules into the Android Demo image for CM-T335, as all the kernel driver modules are compiled in the kernel binary.}}

== Basic platform support ==
The CM-T335 basic platform support is implemented in the {{filename|arch/arm/mach-omap2/board-cm-t335.c}} file of Linux kernel source tree. This file includes default setup of multi-functional pins, registration of the devices integrated in the CM-T335 module and definitions of platform-specific configuration for these devices.

=== USB Gadget ===
The CM-T335 Android Demo image supports both USB host and USB device ports.
USB host can be used to connect Keyboard/Mouse, Mass storage device, etc.
The USB device port is used for connecting to a PC workstation.<br/>
To enable/disable USB Gadget support in the kernel configuration menu choose {{parameter|Device Drivers--->USB support--->USB Gadget Support}} submenu.
Then enable/disable {{parameter|USB Gadget Drivers}}:
<pre>
┌───────────────────────────── USB Gadget Support ──────────────────────────────┐
│ Arrow keys navigate the menu. <Enter> selects submenus --->. Highlighted │
│ letters are hotkeys. Pressing <Y> includes, <N> excludes, <M> modularizes │
│ features. Press <Esc><Esc> to exit, <?> for Help, </> for Search. Legend: │
│ [*] built-in [ ] excluded <M> module < > module capable │
│ ┌───────────────────────────────────────────────────────────────────────────┐ │
│ │ --- USB Gadget Support │ │
│ │ [ ] Debugging messages (DEVELOPMENT) │ │
│ │ [ ] Debugging information files (DEVELOPMENT) │ │
│ │ [ ] Debugging information files in debugfs (DEVELOPMENT) │ │
│ │ (2) Maximum VBUS Power usage (2-500 mA) │ │
│ │ (2) Number of storage pipeline buffers │ │
│ │ <*> USB Peripheral Controller (Inventra HDRC USB Peripheral (TI, ADI,│ │
│ │ <*> USB Gadget Drivers (Android Gadget) ---> │ │
│ └───────────────────────────────────────────────────────────────────────────┘ │
├───────────────────────────────────────────────────────────────────────────────┤
│ <Select> < Exit > < Help > │
└───────────────────────────────────────────────────────────────────────────────┘
</pre>
Finally choose {{parameter|Android Gadget}} option:
<pre>
┌──────────────────────── USB Gadget Drivers ────────────────────────┐
│ Use the arrow keys to navigate this window or press the hotkey of │
│ the item you wish to select followed by the <SPACE BAR>. Press │
│ <?> for additional information about this option. │
│ ┌─────────^(-)───────────────────────────────────────────────────┐ │
│ │ ( ) File-backed Storage Gadget (DEPRECATED) │ │
│ │ ( ) Mass Storage Gadget │ │
│ │ ( ) Serial Gadget (with CDC ACM and CDC OBEX support) │ │
│ │ ( ) MIDI Gadget (EXPERIMENTAL) │ │
│ │ ( ) Printer Gadget │ │
│ │ (X) Android Gadget │ │
│ └─────────v(+)───────────────────────────────────────────────────┘ │
├────────────────────────────────────────────────────────────────────┤
│ <Select> < Help > │
└────────────────────────────────────────────────────────────────────┘
</pre>

The relevant initialization including the pin-muxing for MMC bus is done in the CM-T335 board file.
Please refer to the CM-T335 board file {{filename|kernel/arch/arm/mach-omap2/board-cm-t335.c}} for more details.

== See also ==
* [[CM-T335: Android: Getting started]]
* [[CM-T335: Android]]
* [[CM-T335: Android: Building images]]
* [[Android: ADB setup]]
* [http://processors.wiki.ti.com/index.php/TI-Android-JB-4.1.2-DevKit-4.0.1_DeveloperGuide TI Android Developer Guide]

[[Category:Android]]
[[Category:CM-T335]]

@@ Line 38: / Line 38: @@
 <pre>
 cd /home/development/cm-t335/android
-git clone -b rowboat-jb git://gitorious.org/rowboat/prebuilts-gcc-linux-x86-arm-arm-eabi-4_6.git
+git clone -b rowboat-jb https://gitorious.org/rowboat/prebuilts-gcc-linux-x86-arm-arm-eabi-4_6.git
 </pre>
@@ Line 46: / Line 46: @@
 <pre>
 cd /home/development/cm-t335/android
-git clone git://gitorious.org/rowboat/kernel.git
+git clone https://gitorious.org/rowboat/kernel.git
 </pre>
 * Create a branch for CM-T335 development. The CM-T335 patches are generated vs. [http://gitorious.org/rowboat/kernel/commit/996686459db1181a5deaf5d493681ecb5bf43ad7 rowboat-jb-am335x-4.1.2] tag (996686459db1181a5deaf5d493681ecb5bf43ad7 commit) in the Rowboat kernel tree. It is recommended to use exactly the same baseline to avoid merge conflicts:
@@ Line 55: / Line 55: @@
 <pre>
 cd /home/development/cm-t335/android/kernel
-git apply /path/to/cm-t335-android/kernel/linux-3.2.0-cm-t335-3.patch
+git apply /path/to/cm-t335-android/kernel/linux-3.2.0-cm-t335-3.1.patch
 </pre>
 === Building the kernel ===

@@ Line 30: / Line 30: @@
 <pre>
 cd /home/development/cm-t335/android/kernel
-git apply /path/to/cm-t335-android/kernel/linux-3.2.0-cm-t335-1.patch
+git apply /path/to/cm-t335-android/kernel/linux-3.2.0-cm-t335-2.patch
 </pre>

CM-T335: Android: Kernel - Revision history

Ilya: /* Getting kernel sources */

Ilya: /* Overview */

Ilya: /* Getting kernel sources */

Grinberg: /* See also */