imx6-dk ARM A9 Development Kit Linux Development Guide

Transcription

1 imx6-dk ARM A9 Development Kit Linux Development Guide Cadia Networks Laguna Hills, CA Tel: Doc Number: R Revision 1.1 January 22, 2014

2 Table of Contents INTRODUCTION... 3 WELCOME...3 THE Cadia LINUX DISTRIBUTION FOR THE I.MX6 DK...3 BOOTING THE Cadia I.MX6 DEVICE...3 LOGGING IN TO THE DEFAULT CONSOLE...3 THE DEVELOPMENT ENVIORNMENT... 4 DEVELOPMENT REQUIREMENTS...4 DEVELOPMENT VIRTUAL MACHINE USERNAME AND PASSWORD:...4 IMPORTING THE VIRTUAL PC DEVELOPMENT ENVIRONMENT...4 DEFAULT DEMO APPLICATIONS... 8 HELLO WOLRD TEXT...8 HELLO WOLRD GTK...8 GPIO...8 ANALOG IN...8 AIO EXTENSION BOARD...8 PIO EXTENSION BOARD...8 USER INTERRUPTS...8 PWM...8 INTERFACE SPECIFIC NOTES... 9 LEDS...9 CAN PORTS...9 SYSTEM TIME...9 TOUCH PANEL...9 ANALOG INPUTS...10 DIGITAL I/O...10 DIP SWITCHES...10 HARDWARE MONITORING...11 WIFI MODULE CONFIGURATION...11 SERIAL PORT CONFIGURATION...12 AUDIO OUTPUTS...12 DEVELOPING AN APPLICATION...13 OPENING AND REBUILDING AND APPLICATION...13 DEBUGGING AN APPLICATION...13 MODIFYING THE OPERATING SYSTEM...15 ADDING A MODULE...15 Page i of 19

3 MAKING A SOURCE CODE CHANGE...15 MODIFYING THE BOOT ENVIORNMENT...16 SETTING LCD...16 SETTING HDMI...16 RESETTING THE DEFAULT U BOOT ENVIRONMENT VARIABLES...16 FLASHING THE MICRO SD CARD...17 FLASHING THE ENTIRE CARD (U BOOT, KERNEL, ROOTFS)...17 FLASHING THE KERNEL...17 FLASHING U BOOT AND ERASING THE U BOOT ENVIRONMENT VARIABLES...17 CHANGING THE SPLASH SCREEN...18 CHANGING THE SPLASH SCREEN...18 Page 2 of 19

4 INTRODUCTION Welcome Thank you for buying our products Cadia Networks. Our customer relationships go well beyond the specs of our boards & systems, price and availability. We strive for a strong and reliable business to business partner supplying you with the best available product with the highest level of quality without any supply-chain disruptions. This document shows a developer how to get started with a Linux environment. We assume the reader has a general working knowledge of Linux and understands basic Linux functions. The Cadia Linux Distribution for the i.mx6-dk and the A9-QSB This particular distribution of Linux is derived from Freescale s L3.0.35_4.0.0 distribution. It is based off the Kernel, which has been modified to include a BSP and custom Kernel that suits all of the Cadia i.mx6 series of boards. We have included all the modules necessary to use the hardware features on our boards. All of the i.mx6 boards use the same BSP meaning whether you develop with the standalone A9-SOM, or the IMX6-DK, you will develop with the MACH_TYPE_MX6Q_CADIAQSB BSP. Booting the Cadia i.mx6 Device Booting a Cadia i.mx6 device is easy. Simply plug the power supply that was included in your development kit into the unit and watch the board boot. The unit will automatically boot from the micro-sd card. After 30 seconds, the unit will display a generic Matchbox windowed interface (imx6-dk). You can use the touch panel or a USB mouse to navigate to applications. Some demo applications can be run immediately from the Cadia Example Apps directory. Logging in to the Default Console After booting the device, you may log in through the default console. /dev/ttymxc0 (COM1) is used as the default console, and has serial settings , 8, N, 1. Both the IMX6-DK and A9-SOM serial ports are DTE type, and will require a crossover cable to establish a PC connection. Default login is as follows: Username: root Password: Cadia You may also SSH or telnet through the network interface if you have a network connection. The wired Ethernet port is set to auto-configure via DHCP on boot, so many users may find this access method easier, especially if no serial port is available.

5 THE DEVELOPMENT ENVIORNMENT Development Requirements Developing code for the Cadia i.mx6 series boards is straightforward. Cadia supplies a complete virtual machine in its development kit that contains all source code, documentation, script files, and applications necessary to get started. The virtual machine environment is Ubuntu 12.04LTS. We officially support VirtualBox on a Windows 7 PC as the host the virtual machine. Many other host environments should work equally well. See for the free download or check the development kit for a known stable release. You will also need to install the Virtual Box Extension Pack (after installing VirtualBox) in order to support USB 2.0, which is generally required in order to re-flash the u-boot, kernel, and roof file system(rfs) onto an SD card. Development Virtual Machine Username and Password: The default sudo username is Cadia, the password is Cadia. Importing the Virtual PC Development Environment Some PCs have a BIOS setting that you must enable for the machine to boot correctly in an x64 environment. While this setting is particular to each motherboard, the setting description is generally Enable Machine Virtualization. Make sure to have this set before continuing. In the VirtualBox settings dialog, you will need to customize your VirtualBox with settings particular to your development PC, including serial port settings, network adapters, USB devices, and audio devices. To import the Virtual Machine, select file->import Appliance. Follow the wizard and import the Virtual Machine into VirtualBox. The Virtual Machine is large, approximately 20GB. Depending on your host system, it will take about 30 minutes to import. Page 4 of 19

6 When setting up the VirtualBox host settings, set the network adapter type to Bridged Adapter, otherwise FTP transfers will not work. (Machine->Settings>Network->Adapter1->AttachedTo) Also, be sure to enable the serial port if you plan to use the virtual machine for the default console device. A terminal emulator (Putty) is pre-installed on the Unity Launcher on the left-hand side. Filezilla, a popular FTP client, and a couple of text editors are also pre-installed for your use. Page 5 of 19

7 Finally, be sure to install the Virtual Box Guest Additions in order to support USB 2.0 and Host/Client file sharing. Once you select the Install Guest Additions it will download and mount the Additions as an ISO file in your Unity Launcher. Open the disk by clicking on it, and then select Open Autorun Prompt : Page 6 of 19

8 After the VirtualBox Additions have been installed, you should have these features available: Host/Client filesharing, Bi-directional copy paste, and USB2.0 support. The USB will generally be necessary to re-flash new software onto your micro-sd card. Page 7 of 19

9 DEFAULT DEMO APPLICATIONS We have provided a few demo applications for our customers that demonstrate the I/O functionality of the imx6- DK and A9-SOM boards. Each application demonstrates a simple function that a developer may want to use. Demonstration programs are located in the /usr/bin/ directory and can be run in place. Source code for each demo is located in the Projects directory on the desktop of the development virtual machine. Helo Wolrd Text World s most simple Linux program. This was provided so that customers have a pre-configured text environment for the Eclipse IDE. Helo Wolrd GTK World s most simple Linux GTK program. This was provided so that customers have a pre-configured GTK environment for the Eclipse IDE. GPIO Demonstrates the 8 digital I/O ports on the IMX6-DK board. The demo shows the use of the gpio sysfs class to access the ports from user space. The inputs and outputs are directly connected to a gpio pin on the cpu, so be careful when connecting these pins. TTL levels are a nominal 3.3V. See the user schematic for details on these ports. Analog In On the IMX6-DK board, there is a 12-bit analog input available. Use this demo to read the value of the input. AIO Extension Board Demonstrates the AIO extension board. This is also a good reference for the SPI and I2C interfaces that are brought out on the extension bus header. PIO Extension Board Demonstrates the PIO extension board. This is a good reference for the SPI bus. User Interrupts Demonstrates the user interrupt pins that are available on the extension bus header. Provides a good example of handling an interrupt from user space. PWM Demonstrates the pulse width modulation pin (SOM pin 49) that available on J11 header of the IMX6-DK. The pwm driver uses the PWM-Backlight driver to modify both period and duty cycle. Page 8 of 19

10 INTERFACE SPECIFICNOTES The following quick reference notes will help you get started with your project. They are not exhaustive, but they aid in quickly testing that an interface is functional. LEDs On-Board SOM leds can be toggled using the following gpio pins: gpio44, gpio45, gpio46, gpio47 Switching on led1: echo 0 > /sys/class/gpio/gpio44/value Switching off led 3: echo 1 > /sys/class/gpio/gpio46/value CAN Ports Bring the interface up: ip link set can0 up type can bitrate Bring the interface down: ifconfig can0 down send a packet: cantest can0 121#DEADBEEF (121 is hex ID, DEADBEEF is 4 byte packet) receive a packet: cantest can0 System Time Set the system time with the following commands: date -s [yyyy][mm][dd][hh][mm].[ss] (example: date -s will set the system time to October 16, 2013 at 8:47am.) hwclock -w (this writes the system time to the hardware clock, so that the correct time will be loaded when the system during the next startup). This assumes you have a backup battery installed in your system, either on the A9-SOM or the baseboard. Touch Panel Locations for touch configuration: /etc/profile: TSLIB_TSDEVICE=/dev/input/ts0 /etc/rc.d/init.d/fslgnome: export TSLIB_TSDEVICE=/dev/input/ts0 /etc/rc.d/init.d/fslgnome: export TSLIB_CALIBFILE=/usr/etc/pointercal Page 9 of 19

11 Touchscreen device name: /dev/input/ts0 Calibrating the touchscreen: /usr/bin/ts_calibrate Analog Inputs Reading the onboard analog inputs is easy. Simply cat the device input: cat /sys/devices/platform/imx-i2c.2/i2c-2/2-0048/aux_input (analog channel ) Output is in millivolts. Digital I/O The IMX6-DK board has 8 input/output pins built on the board. Each port, can be either an input or output, and all pins have a nominal 3.3V logic level. Refer to the demo application to see how these bits are used. The gpio bits are indexed gpio Read bit0 example: echo in >> /sys/class/gpio/gpio146/direction (this will set pin 0 direction to input) cat /sys/class/gpio/gpio146/value Write bit0 example: echo out >> /sys/class/gpio/gpio146/direction (this will set pin 0 direction to output) echo 1 >> /sys/class/gpio/gpio146/value (this will set pin 0 to +3.3V) Dip Switches There are three user available dip switches on the A9-SOM (SW2). Each dip value is available to be read are read from gpio240-gpio243. Dip switch 0 is reserved, and is used to determine the whether the system boots from gpio pins, or from internal boot fuses. This is an advanced option, and generally not supported. Read dip0: RESERVED FOR SYSTEM USE Read dip1: cat /sys/class/gpio/gpio2/value Read dip2: cat /sys/class/gpio/gpio4/value Read dip3: cat /sys/class/gpio/gpio6/value Page 10 of

12 Hardware Monitoring There is an onboard temperature sensor internal to the touch controller. It can be used to make rough temperature measurements. It s accuracy is +/- 2degC or +/-3.6degF which makes is suitable for general purpose measurements. Reading the temperature measurement is easy. Simply cat the device input: cat /sys/devices/platform/imx-i2c.2/i2c-2/2-0048/temp_input (temp channel ) Output is in degc. WIFI Module Configuration The optional Cadia wifi module can be installed on any of our baseboards. When the wifi module is installed on the A9-SOM, it uses the USB host port, and prevents any other USB device from being attached. If you attach the wifi module to the IMX6-DK, the wifi module is attached to an on-board hub which allows for an additional 3 devices to be attached. To configure the Cadia wifi module, use a combination of the ifconfig and iwconfig commands. Here is a standard, open, unencrypted configuration example. You will need to modify your ip address, gateway, nameserver, security, and netmask for your particular network. ifconfig wlan0 up iwconfig wlan0 mode managed iwconfig wlan0 key off iwconfig wlan0 enc off iwconfig wlan0 essid any option 1 (static ip): ifconfig wlan route add default gw echo nameserver >> /etc/resolve.conf option 2 (dynamic ip): udhcpc i wlan0 & option 3 (encryption on) ifconfig wlan0 up Page 11 of 19

13 Next, you need to use wpa_supplicant utility to connect: 1. Modify /etc/wpa_cupplicant.conf for your network. 2. call /usr/local/sbin/wpa_supplicant Dwext iwlan0 c/etc/wpa_supplicant.conf B 3. After connection, either setup as staic or dynamic IP (see above) Serial Port Configuration The modules for the serial ports and for the serial port add-on card are preinstalled. The serial ports will default to 9600, 8, N, 1 and the descriptors are as follows: COM1: /dev/ttymxc0 COM2: /dev/ttymxc1 (Optional I/O module) COM3: /dev/ttyusb0 COM4: /dev/ttyusb1 COM5: /dev/ttyusb2 COM6: /dev/ttyusb3 Changing the baud rate to is easy: stty -F /dev/ttymxc Audio Outputs There are two audio outputs on the I.MX6: the sgtl5000 headphone output and the HDMI output. If HDMI is set as the display, the output will default to the hdmi. Otherwise the audio output will default to the on-board headphone jacks. This default behavior can be modified in the mx6_cadiaqsb_board_init() function of /linux /arch/arm/mach-mx6/board-mx6q_Cadiaqsb.c Sample audio wav file command: aplay test.wav Page 12 of 19

14 MODIFYING THE OPERATING SYSTEM DEVELOPING AN APPLICATION Within the virtual machine, we ve provided a pre-configured development environment that allows you to quickly write and deploy an application. We ve written a few demonstration programs (GTK) that show you how to use some of the custom I/O features on the boards. Each of these demos has been developed in the Eclipse IDE, and they are pre-configured so that you may debug them over a network connection. This procedure is the same, regardless of whether you are running LTIB or Ubuntu. The following example shows how to run the gpio demo: Opening and Rebuilding andapplication Open the eclipse IDE from the unity launcher (purple sphere). Next, open the GPIO project by right clicking and opening. From here you can browse and modify the source code. To rebuild the project, click Project-> build project. Page 13 of 19

15 MODIFYING THE OPERATING SYSTEM Debugging anapplication The only setting we need to know for debugging an application will be the IP address of the development device. Everything else is pre-configured. To enter the IP address, click the Remote System Explorer button on the top toolbar. Right click the Caida_IMX6 icon and select properties. In the host sub-menu, enter the ip address of the development device you would like to debug. Click OK. Use the login and password for the user that is running the X desktop. To debug the project, click the arrow next to the bug icon and select the CADIA_IMX6_PWM option. The VM will then try to deploy the application and start debugging. A prompt for a password will appear the first time you deploy the application. From here the application will deploy and you can insert break-points, inspect variables, inspect memory, etc. Modifying the BSP to include or exclude specific modules is easy. You can also modify the kernel source to fit your requirements. All source is located in the Linux on your desktop under the directory Linux_L The generated kernel from LTIB can be used with the Ubuntu rootfs. Adding a Module Adding a module is straightforward. Open a terminal and navigate to the ~Desktop/ Linux_L2.6.35/ltib directory. Run./ltib c This will bring up ltib in configuration mode. Go through the menus and find the module you want and select it. Once selected, exit and save your changes. LTIB then runs and includes your module. After the image is made, simply re-flash the entire SD card. Making a source code change To modify source code, make your source changes, and then navigate to the ~Desktop/ Linux_L2.6.35/ltib directory. Run./ltib LTIB will take care of recompiling re-creating the image. If your change was to kernel code, re-flash the kernel onto the SD card. Otherwise you can copy your affected module, or re-flash the entire card. Page 14 of 19

16 MODIFYING THE BOOTENVIORNMENT A few display options need to be configured in the U-Boot environment. Specifically, if you want to change the primary display to HDMI instead of the built-in touch LCD, then you will need to make some environment changes. Setting LCD as Primary Display This is the default display option. It displays a graphical desktop on the touch-panel display attached to the FS- IMX6-DK. U-Boot s out of the box default is this option. To set back to this option, set the bootargs_base variable in U-Boot: set bootargs_mmc setenv bootargs ${bootargs} root=/dev/mmcblk0p1 rootwait video=mxcfb0:dev=lcd,samsung-wvga,if=rgb24 video=mxcfb1:dev=hdmi,1920x1080m@30,if=rgb24 fbmem=10m,28m Setting HDMI as Primary Display In order to use the HDMI port, the output must be configured as follows in U-Boot: set bootargs_mmc setenv bootargs ${bootargs} root=/dev/mmcblk0p1 rootwait video=mxcfb0:dev=hdmi,1920x1080m@30,if=rgb24 video=mxcfb1:dev=lcd,samsung-wvga,if=rgb24 fbmem=28m,10m Resetting the Default U-Boot Environment Variables In the u-boot environment perform the following commands: destroyenv, reset, save, reset. Page 15 of 19

17 FLASHING THE MICRO-SD CARD We have written a few script files that can be called on the development PC that flashes the Micro-SD cards for use with the CADIA i.mx6 Micro/Plus/Lite boards. Use them in your development and production as necessary. Flashing the Entire Card (U-Boot, Kernel, rootfs) There are two distributions for the CADIA-IMX6 Boards, LTIB and Ubuntu. Both can be flashed to an SD card and run on your system. For LTIB: ~/Desktop/Linux_L3.0.35_4.0.0/flash-format-uboot-kernel-ltib.sh /dev/sde (where /dev/sde is your particular SD card interface) For Ubuntu: ~/Desktop/Linux_L3.0.35_4.0.0/flash-format-uboot-kernel-ubuntu.sh /dev/sde (where /dev/sde is your particular SD card interface) Flashing the Kernel ~/Desktop/ Linux_L3.0.35_4.0.0/flash-kernel-only.sh /dev/sde (where /dev/sde is your particular SD card interface) Flashing U-boot and Erasing the U-boot Environment Variables ~/Desktop/ Linux_L3.0.35_4.0.0/flash-uboot-only.sh /dev/sde (where /dev/sde is your particular SD card interface) The default environment variables are located in ~/Desktop/Linux_L3.0.35_4.0.0/ltib/rpm/BUILD/u-boot /include/configs/mx6q_Cadiaqsb.h Page 16 of 19

18 CHANGING THE SPLASH SCREEN By default, the CADIA logo appears when you boot the device. You can change this splash screen to your own company logo by following this procedure: Changing the Splash Screen To change the splash screen of linux kernel, first create the graphic you want to use and save it as a.ppm file. You can use Gimp on the development PC to do this. Next, change to "logo" folder <ltib_path>/rpm/build/linux /drivers/video/logo Run: ppmquant -mapfile clut_vga16.ppm "my_image.ppm" pnmnoraw > logo_linux_vga16.ppm ppmquant -mapfile clut_vga16.ppm "my_image.ppm" pnmnoraw > logo_linux_clut224.ppm Finally: rebuild the kernel, and re-flash the kernel onto your micro SD card. Page 17 of 19