AN809 Datasheet, PDF (1/10 Pages) Silicon Laboratories – VIRTUAL COM PORT DRIVER INTO THE ANDROID PLATFORM

AN809
INTEGRATING THE CP210X VIRTUAL COM PORT DRIVER
INTO THE ANDROID PLATFORM
1. Introduction
This document describes how to build an Android kernel and the steps needed to integrate the CP210x virtual
COM port (VCP) driver in to the build.
Android is based off of the Linux kernel, so there is already support for the CP210x device built in to the kernel.
However, CP210x support is not included in a default kernel build configuration for most Android devices.
There are many devices that can run the Android operating system (OS), as well as several different versions of an
Android operating system. Because Android is open source, it can be changed based on the needs of device
manufacturers, wireless carriers and other developers. This fact makes it difficult to provide the exact steps for
rebuilding, as each developer may be using different hardware and a different build of Android specific to that
hardware.
This document was written based on the experience of building an Android Jelly Bean (4.3.1) kernel for a
PandaBoard using a TI OMAP4430 processor. The Android port used originates from the 13.10 release from
Linaro. Build materials and information on this specific release can be found at http://releases.linaro.org/13.10/
android/panda/. If you are using another platform, you should consult the manufacturer's website to get the
Android distribution support for your device. Although the steps below are targeted to Jelly Bean on the
PandaBoard, developers can follow similar steps to download and rebuild the kernel for other platforms. For any
other needs specific to Android, visit the Android Developer website at
http://developer.android.com.
2. Materials
To build a custom Android kernel and image, you will need:
CP210x USB to UART Bridge Evaluation Board
Target Android Device (PandaBoard)
SD card to hold OS
Any cables for connectivity (HDMI video cable, network cable, USB power cable, USB to RS232 adapter)
Source Distribution for Target Android Version (Linaro 13.10 - JellyBean 4.3.1 Android Release for
PandaBoard)
Toolchain to build the Source Distribution (Android NDK, Revision 9C)
Development System Running Linux (Ubuntu 12.04 LTS)
3. Overview
The basic steps to integrate support for the CP210x driver are:
Create bootable image on an SD Card from the Android source distribution
Download the Android build tools for the target Android source and platform
Download the Android source tree for the target platform
Modify the configuration of the kernel to include the CP210x and other required drivers
Build and install the new image to the target platform media
Rev. 0.1 1/14
Copyright © 2014 by Silicon Laboratories
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