[linuxkernelnewbies] Uboot Guide

[Peter Teoh]

http://www.denx.de/wiki/bin/view/DULG/Manual    The DENX U-Boot and Linux Guide (DULG) for canyonlands Table of contents: 1. Abstract 2. Introduction 2.1. Copyright 2.2. Disclaimer 2.3. Availability 2.4. Credits 2.5. Translations 2.6. Feedback 2.7. Conventions 3. Embedded Linux Development Kit 3.1. ELDK Availability 3.2. ELDK Getting Help 3.3. Supported Host Systems 3.4. Supported Target Architectures 3.5. Installation 3.5.1. Product Packaging 3.5.2. Downloading the ELDK 3.5.3. Initial Installation 3.5.4. Installation and Removal of Individual Packages 3.5.5. Removal of the Entire Installation 3.6. Working with ELDK 3.6.1. Switching Between Multiple Installations 3.7. Mounting Target Components via NFS 3.8. Rebuilding ELDK Components 3.8.1. ELDK Source Distribution 3.8.2. Rebuilding Target Packages 3.8.3. Rebuilding ELDT Packages 3.9. ELDK Packages 3.9.1. List of ELDT Packages 3.9.2. List of Target Packages 3.10. Rebuilding the ELDK from Scratch 3.10.1. ELDK Build Process Overview 3.10.2. Setting Up ELDK Build Environment 3.10.3. build.sh Usage 3.10.4. Format of the cpkgs.lst and tpkgs.lst Files 3.11. Notes for Solaris 2.x Host Environment 4. System Setup 4.1. Serial Console Access 4.2. Configuring the "cu" command 4.3. Configuring the "kermit" command 4.4. Using the "minicom" program 4.5. Permission Denied Problems 4.6. Configuration of a TFTP Server 4.7. Configuration of a BOOTP / DHCP Server 4.8. Configuring a NFS Server 5. Das U-Boot 5.1. Current Versions 5.2. Unpacking the Source Code 5.3. Configuration 5.4. Installation 5.4.1. Before You Begin 5.4.1.1. Installation Requirements 5.4.1.2. Board Identification Data 5.4.2. Installation Using a BDM/JTAG Debugger 5.4.3. Installation using U-Boot 5.5. Tool Installation 5.6. Initialization 5.7. Initial Steps 5.8. The First Power-On 5.9. U-Boot Command Line Interface 5.9.1. Information Commands 5.9.1.1. bdinfo - print Board Info structure 5.9.1.2. coninfo - print console devices and informations 5.9.1.3. flinfo - print FLASH memory information 5.9.1.4. iminfo - print header information for application image 5.9.1.5. help - print online help 5.9.2. Memory Commands 5.9.2.1. base - print or set address offset 5.9.2.2. crc32 - checksum calculation 5.9.2.3. cmp - memory compare 5.9.2.4. cp - memory copy 5.9.2.5. md - memory display 5.9.2.6. mm - memory modify (auto-incrementing) 5.9.2.7. mtest - simple RAM test 5.9.2.8. mw - memory write (fill) 5.9.2.9. nm - memory modify (constant address) 5.9.2.10. loop - infinite loop on address range 5.9.3. Flash Memory Commands 5.9.3.1. cp - memory copy 5.9.3.2. flinfo - print FLASH memory information 5.9.3.3. erase - erase FLASH memory 5.9.3.4. protect - enable or disable FLASH write protection 5.9.3.5. mtdparts - define a Linux compatible MTD partition scheme 5.9.4. Execution Control Commands 5.9.4.1. source - run script from memory 5.9.4.2. bootm - boot application image from memory 5.9.4.3. go - start application at address 'addr' 5.9.5. Download Commands 5.9.5.1. bootp - boot image via network using BOOTP/TFTP protocol 5.9.5.2. dhcp - invoke DHCP client to obtain IP/boot params 5.9.5.3. loadb - load binary file over serial line (kermit mode) 5.9.5.4. loads - load S-Record file over serial line 5.9.5.5. rarpboot- boot image via network using RARP/TFTP protocol 5.9.5.6. tftpboot- boot image via network using TFTP protocol 5.9.6. Environment Variables Commands 5.9.6.1. printenv- print environment variables 5.9.6.2. saveenv - save environment variables to persistent storage 5.9.6.3. setenv - set environment variables 5.9.6.4. run - run commands in an environment variable 5.9.6.5. bootd - boot default, i.e., run 'bootcmd' 5.9.7. Flattened Device Tree support 5.9.7.1. fdt addr - select FDT to work on 5.9.7.2. fdt list - print one level 5.9.7.3. fdt print - recursive print 5.9.7.4. fdt mknode - create new nodes 5.9.7.5. fdt set - set node properties 5.9.7.6. fdt rm - remove nodes or properties 5.9.7.7. fdt move - move FDT blob to new address 5.9.7.8. fdt chosen - fixup dynamic info 5.9.8. Special Commands 5.9.8.1. i2c - I2C sub-system 5.9.9. Storage devices 5.9.10. Miscellaneous Commands 5.9.10.1. echo - echo args to console 5.9.10.2. reset - Perform RESET of the CPU 5.9.10.3. sleep - delay execution for some time 5.9.10.4. version - print monitor version 5.9.10.5. ? - alias for 'help' 5.10. U-Boot Environment Variables 5.11. U-Boot Scripting Capabilities 5.12. U-Boot Standalone Applications 5.12.1. "Hello World" Demo 5.12.2. Timer Demo 5.13. U-Boot Image Formats 5.14. U-Boot Advanced Features 5.14.1. Boot Count Limit 5.14.2. Bitmap Support 5.14.3. Splash Screen Support 6. Embedded Linux Configuration 6.1. Download and Unpack the Linux Kernel Sources 6.2. Kernel Configuration and Compilation 6.3. Installation 7. Booting Embedded Linux 7.1. Introduction 7.2. Flattened Device Tree Blob 7.3. Passing Kernel Arguments 7.4. Boot Arguments Unleashed 7.5. Networked Operation with Root Filesystem over NFS 7.5.1. Bootlog of Linux kernel with Root Filesystem over NFS 7.6. Boot from Flash Memory 7.7. Standalone Operation with Ramdisk Image 8. Building and Using Modules 9. Advanced Topics 9.1. Flash Filesystems 9.1.1. Memory Technology Devices 9.1.2. Journalling Flash File System 9.1.3. Second Version of JFFS 9.1.4. Compressed ROM Filesystem 9.2. The TMPFS Virtual Memory Filesystem 9.2.1. Mount Parameters 9.2.2. Kernel Support for tmpfs 9.2.3. Usage of tmpfs in Embedded Systems 9.3. Adding Swap Space 9.4. Splash Screen Support in Linux 9.5. Root File System: Design and Building 9.5.1. Root File System on a Ramdisk 9.5.2. Root File System on a JFFS2 File System 9.5.3. Root File System on a cramfs File System 9.5.4. Root File System on a Read-Only ext2 File System 9.5.5. Root File System on a Flash Card 9.5.6. Root File System in a Read-Only File in a FAT File System 9.6. Root File System Selection 9.7. Overlay File Systems 9.8. The Persistent RAM File system (PRAMFS) 9.8.1. Mount Parameters 9.8.2. Example 10. Debugging 10.1. Debugging of U-Boot 10.1.1. Debugging of U-Boot Before Relocation 10.1.2. Debugging of U-Boot After Relocation 10.2. Linux Kernel Debugging 10.2.1. Linux Kernel and Statically Linked Device Drivers 10.2.2. Dynamically Loaded Device Drivers (Modules) 10.2.3. GDB Macros to Simplify Module Loading 10.3. GDB Startup File and Utility Scripts 10.4. Tips and Tricks 10.5. Application Debugging 10.5.1. Local Debugging 10.5.2. Remote Debugging 10.6. Debugging with Graphical User Interfaces 11. Simple Embedded Linux Framework 12. Books, Mailing Lists, Links, etc. 12.1. Application Notes 12.2. Further Reading 12.2.1. License Issues 12.2.2. Linux kernel 12.2.3. General Linux / Unix programming 12.2.4. Network Programming 12.2.5. C++ programming 12.2.6. Java programming 12.2.7. Power Architecture® Programming 12.2.8. Embedded Topics 12.3. Mailing Lists 12.4. Links 12.5. Tools 13. Appendix 13.1. Flat Device Tree 13.2. BDI2000 Configuration file 14. FAQ - Frequently Asked Questions 14.1. ELDK 14.1.1. ELDK Installation under FreeBSD 14.1.2. ELDK Installation Hangs 14.1.3. .gvfs: Permission Denied 14.1.4. Installation on Local Harddisk 14.1.5. System Include Files Missing 14.1.6. ELDK Include Files Missing 14.1.7. Using the ELDK on a 64 bit platform 14.1.8. GDB Problems with BDI2000/BDI3000 on e500 Cores 14.1.9. [[ELDK Installation Aborts][ELDK 2.x Installation Aborts]] 14.2. U-Boot 14.2.1. Can U-Boot be configured such that it can be started in RAM? 14.2.2. Relocation cannot be done when using -mrelocatable 14.2.3. Source object has EABI version 4, but target has EABI version 0 14.2.4. U-Boot crashes after relocation to RAM 14.2.5. Warning - bad CRC, using default environment 14.2.6. Wrong debug symbols after relocation 14.2.7. Decoding U-Boot Crash Dumps 14.2.8. Porting Problem: cannot move location counter backwards 14.2.9. U-Boot Doesn't Run after Upgrading my Compiler 14.2.10. How Can I Reduce The Image Size? 14.2.11. Erasing Flash Fails 14.2.12. Ethernet Does Not Work 14.2.13. Where Can I Get a Valid MAC Address from? 14.2.14. Why do I get TFTP timeouts? 14.2.15. Why is my Ethernet operation not reliable? 14.2.16. How the Command Line Parsing Works 14.2.16.1. Old, simple command line parser 14.2.16.2. Hush shell 14.2.16.3. Hush shell scripts 14.2.16.4. General rules 14.2.17. How can I load and uncompress a compressed image 14.2.18. How can I create an uImage from a ELF file 14.2.19. My standalone program does not work 14.2.20. Linux hangs after uncompressing the kernel 14.3. Linux 14.3.1. Linux crashes randomly 14.3.2. Linux crashes when uncompressing the kernel 14.3.3. Linux Post Mortem Analysis 14.3.4. Linux kernel register usage 14.3.5. Linux Kernel Ignores my bootargs 14.3.6. Cannot configure Root Filesystem over NFS 14.3.7. Linux Kernel Panics because "init" process dies 14.3.8. Unable to open an initial console 14.3.9. System hangs when entering User Space (ARM) 14.3.10. Mounting a Filesystem over NFS hangs forever 14.3.11. Ethernet does not work in Linux 14.3.12. Loopback interface does not work 14.3.13. Linux kernel messages are not printed on the console 14.3.14. Linux ignores input when using the framebuffer driver 14.3.15. How to switch off the screen saver and the blinking cursor? 14.3.16. BogoMIPS Value too low 14.3.17. Linux Kernel crashes when using a ramdisk image 14.3.18. Ramdisk Greater than 4 MB Causes Problems 14.3.19. Combining a Kernel and a Ramdisk into a Multi-File Image 14.3.20. Adding Files to Ramdisk is Non Persistent 14.3.21. Kernel Configuration for PCMCIA 14.3.22. Configure Linux for PCMCIA Cards using the Card Services package 14.3.23. Configure Linux for PCMCIA Cards without the Card Services package 14.3.23.1. Using a MacOS Partition Table 14.3.23.2. Using a MS-DOS Partition Table 14.3.24. Boot-Time Configuration of MTD Partitions 14.3.25. Use NTP to synchronize system time against RTC 14.3.26. Configure Linux for XIP (Execution In Place) 14.3.26.1. XIP Kernel 14.3.26.2. Cramfs Filesystem 14.3.26.3. Hints and Notes 14.3.26.4. Space requirements and RAM saving, an example 14.3.27. Use SCC UART with Hardware Handshake 14.3.28. How can I access U-Boot environment variables in Linux? 14.3.29. The =appWeb= server hangs *OR* /dev/random hangs 14.3.30. Swapping over NFS 14.3.31. Using NFSv3 for NFS Root Filesystem 14.4. Self 14.4.1. How to Add Files to a SELF Ramdisk 14.4.2. How to Increase the Size of the Ramdisk 14.5. RTAI 14.5.1. Conflicts with asm clobber list 14.6. BDI2000 14.6.1. Where can I find BDI2000 Configuration Files? 14.6.2. How to Debug Linux Exceptions 14.6.3. How to single step through "RFI" instruction 14.6.4. Setting a breakpoint doesn't work 14.7. Motorola LITE5200 Board 14.7.1. LITE5200 Installation Howto 14.7.2. USB does not work on Lite5200 board 15. Glossary