This document provides an overview of using the TMS320DM8148 embedded processor with Linux. It discusses the hardware architecture supported by Linux, the embedded development board setup, toolchain and compiler installation, bootloaders, the Linux kernel, device drivers, file systems and more. The goal is to enable development of embedded Linux applications for the TMS320DM8148 chip using common open source tools.

1. TMS320DM8148 Embedded
Linux
Overview

2. Introduction
• Linux Kernel & Components used in
embedded system
• Embedded Linux Devices everywhere around
us
– Android Phones
– Digital & Smart TVs
– Set Top Boxes

3. Embedded Hardware Architecture
• Linux Kernel supports 32 & 64 bit architectures
– X86 & x86-64
– ARM
– Power PC
– MIPS
– SuperH
– BlackFin
– Microblaze
– ColdFire, AVR32

4. Architecture
Embedded Board
Host PC
Root File System
Linux Kernel & drivers
Boot Loader
C Libraries linux services / commands
ApplicationsCross
Compiler
JTAG
Debugger
Source
Code

5. Development PC - Compiler
• Code Sourcery ARM Tool Chain
– Version 2009-q1
– arm-2009q1-203-arm-none-linux-gnueabi-i686-
pc-linux-gnu.tar
• https://sourcery.mentor.com/GNUToolchain/release18
02?
• Download IA32 GNU/LINUX TAR
• Codesourcery Commercial Edition
– Evaluation version of commercial edition

6. Development PC – Compiler Setup
• Uncompress the Compiler Zip File
– tar xvf arm-2009q1-203-arm-none-linux-gnueabi-i686-pc-linux-gnu.tar
• Move to /opt/ custom software folder in ubuntu
– mkdir /opt/CodeSourcery
– mv arm-2009q1 /opt/CodeSourcery/Sourcery_G++_Lite
• Adding the toolchain path into shell
– vi ~/.bashrc
• export PATH=/opt/CodeSourcery/Sourcery_G++_Lite/bin:$PATH
– source ~/.bashrc

7. Development PC - Tools
• JTAG Debugger
– This tool is used when new hardware is designed
– Used to validate & bring up low level hardware
interfaces ( DDR3, NAND Flash )
– XDS 560 V2 System Trace Emulator
– XDS 560 PCI Rev D Emulator
– Blackhawk USB 560-M Emulator
– Spectrum Digital 510 USB Emulator
• Code Composer Studio

8. Development PC - Console
• Serial Console
– Used to get boot up log messages & acts as linux shell
to execute the applications
– Default settings : 115200 8N1
– Flow Control : None
• Minicom
– Text based modem control & terminal emulation
utility
– PC Serial console
– Run “minicom –S” to configure the serial console

9. Development PC – EZSDK
• EZSDK
– Linux EZ Software Development Kit
– Linux support based on 2.6.37 Kernel
– Quick Start Development
– Video / Audio Codecs
– DSP accelerated alogrithms
– Application Examples – Networked Audio / Video
– Qt graphics SDK plugin
– OpenMax libraries
– Matrix Application Launcher

10. EZSDK - Architecture

11. EZSDK - Components
• Linux Kernel 2.6.37
• Bootloader
• File System
• Qt/Webkit application framework
• 3D Graphics Support
• Flash Tools & Pin Muxing Utility
• HDVICP2 Accelerated Codec
– H.264 Encode / Decode, MPEG4 Encode / Decode,
MPEG2 Decode & VC1/WMV9 to the video detector

12. Boot Loader
• 1st stage boot loader
– TI 814x BOOT ROM
• 2nd & 3rd stage boot loader
– U-Boot Loader
– U-Boot-MIN Image
• Prompt TI-MIN#
– U-Boot Image
• Prompt TI8148_EVM#
• NOR Boot
– Has only two stage bootloader
– U-Boot-MIN is not required as NOR is XIP ( eXecute In
Place )

13. Two Stage U-Boot Design
• TI814x internal RAM
– 128 KB out of which 18 KB at the end used by ROM Code
– Limit of 110KB on the size of U-Boot binary can be
transferred to internal RAM
– It needs to setup TEXT_BASE of U-Boot
• 1st stage of U-Boot built with configuration as minimal
as possible
– Purpose to initialize the necessary peripherals especially
DDR SDRAM
– Provides mechanism to load full fledged U-Boot into DDR
& then passed control over it.
– Automatic DDR2 & DDR3 selection

14. U-Boot-MIN
• Different Boot Modes
– NAND/SPI Memory Boot
• Header needs to be attached with binary to indicate load
address.
• SPI boot requires endian information as well
– UART/EMAC/SD Card Peripheral Boot
• No header
• Load Address is fixed ( 0x80070000)
– NOR Flash Boot
• Header is not required
• 1st stage U-Boot is not required, as it is eXecute In Place (XIP)

15. U-Boot Loader
• 2nd stage of U-Boot
– Supports saving environment variables into
• NAND / SPI Flash
• SD Card
• NOR Flash
– Storage media will be configured before building of 2nd
stage U-Boot
• Supported with Storage Media
– Write & Read files ( like boot, kernel, filesystem images )
back from storage media
– Loads kernel image & execute the same
• Loads from Storage
• Loads from TFTP server using Ethernet

16. U-Boot Loader – Kernel Boot
• Boot from NAND
– nand read.i 0x81000000 280000 500000
– bootm 0x81000000
• Boot from SPI
– sf read 0x81000000 0x42000 0x200000
– bootm 0x81000000
• Boot from NOR
– cp.w 0x08060000 0x81000000 0x200000
– bootm 0x81000000
• Boot over Network
– tftp 0x81000000 uImage
– bootm 0x81000000

17. Linux Kernel
• Unix Like computer operating system kernel
• Default kernel configuration
– ti8148_evm_defconfig
• Kernel Image format
– uImage – U-Bootloader based image
– mkimage utility used to create linux kernel image

18. Linux Kernel
• Manages all the hardware peripherals like
CPU, Memory, IO
• Provides an interface for user space
application & libraries to access hardware
interfaces
• Manages multiple user access
– Provides a hardware interface access for multiple
user application access

19. Linux Kernel – Block Diagram
Memory
Management
block - HW MMU
Scheduler & Task
Management
File System
Device Drivers
Low Level CPU
initialization
Network Stack
Device
Tree
Hardware
Description

20. Linux Kernel – Device Drivers
• Power Management
• GPIO Driver
• EDMA3 Driver
• Audio Driver
• SATA Driver
• USB Driver
• SD / MMC Card Driver
• Ethernet Switch Driver
• VPSS Video Driver
– VPSS Video Capture Driver
• HDMI Driver
• McSPI Driver
• PCI Express Root Complex Driver
• PCI Express End Point Driver
• Touch Screen Driver
• Watchdog Timer

21. File System
• Root File System
– Ramdisk
– Cramfs
– Ext 2,3,4
– FAT
• Pseudo file system
– Proc
– Sysfs
– Dev Filesystem

22. Root File System Structure
• bin
• boot
• dev
• etc
• lib
• lost+found
• misc
• mnt
• net
• opt
• proc
• root
• sbin
• tmp
• usr
• Var

23. Contact US
• For Embedded Design Service
• Web : www.neeveetech.com
• Sales : sales@neeveetech.com