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Embedded Linux 2.6 User Manual 1Copyright

1. Boot options gt Default kernel command string ID 29331 Rev 07 2007 Kontron Modular Computers Page 61 Embedded Linux 2 6 User Manual 24 2 3INITRD with ARM Linux Kernel The chapter 14 The Initial Ramdisk INITRD describes how to create the initial ramdisk However when creating the initial ramdisk for ARM architecture following remarks must be taken into account 1 The ramdisk image name should be ramdisk instead of ramdisk image 2 The created ramdisk image should be copied to lt arch gt arm boot compressed directory 24 3NFS mounted Root file system The E Brain 425 420 include two Ethernet Interfaces on board They are provided by XScale IXP425 processor To use these interface proper kernel module drivers must be loaded into memory Because of the license issues these drivers can not be compiled into the kernel Unfortunately to mount the Root file system the kernel must have access to the network during boot process This requirement may not be fulfilled without additional PCI Ethernet card The E Brain 42x evaluation kit contains the Ethernet PCI extension card The default configuration for the kernel provided within the E Brain 42x BSP already contains the proper drivers Chapter 12 6 ys required for booting guards through the NFS server setup and kernel command line configuration Page 62 2007 Kontron Modular Computers ID 29331 Rev 07
2. directory with the desired working directory as a parameter usr x86host gt opt lt linux version gt bsp dir bsp lt boardname gt scripts initproject sh lt work dir gt example usr x86host gt cd usr x86host gt mkdir bspwork usr x86host gt cd bspwork usr x86host bspwork gt opt linux26 bsp dir bsp eb42x scripts initproject sh eb42x project INIT Kontron BSP Project BSP installation directory opt linux26 bsp kom bsp eb42x Project directory home usr bspwork eb42x project initproject finished usr x86host bspwork gt This script generates the following entries under the directory lt work_dir gt edocumentation the online documentation in HTML escripts some useful scripts described later emodules source code and build environment for all Kernel modules provided within the BSP elib source code and build environment for the board library provided within the BSP eapps source code and build environment for all sample applications provided within the BSP einc header files e Makefile the main Makefile steps down into modules lib apps and calls the subordinate Makefiles there eaddl_libs additional libraries and headers which are required for compiling particular applications containing pciutils and sysfsutils e3rd_party_drivers optional directory containing other parties software elm_sensors lt version gt optional directory containing the Lm_sensors source packa
3. 13 1Kernel Configuration and Command Line A description of the required Kernel Configuration and command line can be found in the Linux kernel sources subdirectory Documentation in the file nfsroot txt 13 2NFS Server Setup Set up the development host as an NFS server Refer to the distribution s manuals for information on how to setup an NFS server Then add an entry in the etc exports file to make a directory for the target that is mountable at system start up Refer to the manual page of exports file man exports for details on the specific options Note that the option no root squash is important in order to enable the target to mount this directory as the root directory A line like this must be added to the etc exports file nfsroot lt board type gt rw no root squash no all squash mapping identity anonuid 2 anongid 2 Remember that in the configuration file this should be one line not two as above 13 3Setting Up the Root File System Now the root file system in nfsroot lt boardtype gt is required For this reason it is necessary to unpack the root file system from the Kontron CD ROM into this directory First login as root create the root directory for this archive switch to this directory and unpack the root file system archive from the CD ROM Page 28 2007 Kontron Modular Computers ID 29331 Rev 07 usr x86host gt su Password xxxxx root x86host cd root x86host mkdir nfsroot
4. 0 UP LOOPBACK RUNNING MTU 16436 Metric 1 RX packets 0 errors 0 dropped 0 overruns 0 frame 0 TX packets 0 errors 0 dropped 0 overruns 0 carrier 0 collisions 0 txqueuelen 0 RX bytes 0 0 0 b TX bytes 0 0 0 b S shows all available interfaces However they do not have the IP addresses assigned Following example will configure the ETHO interface with IP address 192 168 3 139 ifconfig ethO 192 168 3 139 up ifconfig a dummy 0 Link encap Ethernet HWaddr F6 03 38 D4 27 EB BROADCAST NOARP MTU 1500 Metric 1 RX packets 0 errors 0 dropped 0 overruns 0 frame 0 Page 60 2007 Kontron Modular Computers ID 29331 Rev 07 TX packets 0 errors 0 dropped 0 overruns 0 carrier 0 collisions 0 txqueuelen 0 RX bytes 0 0 0 b TX bytes 0 0 0 b etho Link encap Ethernet HWaddr 00 02 B3 01 01 01 inet addr 192 168 3 139 Bcast 192 168 3 255 Mask 255 255 255 0 UP BROADCAST RUNNING MULTICAST MTU 1500 Metric 1 RX packets 1 errors 0 dropped 0 overruns 0 frame 0 TX packets 0 errors 0 dropped 0 overruns 0 carrier 0 collisions 0 txqueuelen 256 RX bytes 60 60 0 b TX bytes 0 0 0 b eth1 Link encap Ethernet HWaddr 00 02 B3 02 02 02 BROADCAST MULTICAST MTU 1500 Metric 1 RX packets 0 errors 0 dropped 0 overruns 0 frame 0 TX packets 0 errors 0 dropped 0 overruns 0 carrier 0 collisions 0 txqueuelen 256 RX bytes 0 0 0 b TX bytes 0 0 0 b lo Link encap Local Loopback inet addr 127 0 0 1 Mask 255 0 0 0 UP LOOPBACK RUNNING MTU 16436 Metric 1 RX
5. 193 102 136 43 193 102 136 43 255 255 255 0 eb8347 eth1 root nfs nfsroot nfsroot claugi eb8347 The kernel command line should include at least the root device specification root and console device specification console Depending on the requirements other options may also be included in this command line e g for diskless systems the nfsroot option Page 20 2007 Kontron Modular Computers ID 29331 Rev 07 A complete list of kernel command line options can be found in the Linux kernel sources subdirectory Documentation in the file kernel parameters txt ID 29331 Rev 07 2007 Kontron Modular Computers Page 21 Embedded Linux 2 6 User Manual Here is a typical example of a command line set up with the NetBootLoader chl command NetBtLd gt cbl Bootline common console ttySO 9600 Bootline 0 root dev nfs WO 18 3 102 136 A0SIS S 102 136 4392 193 OA 13613255 PPS EPP EEE ees2 70 eth0 nfsroot nfsroot claugi atc8270 Bootline 1 root dev hdc1 Bootline 2 root dev hda1 Bootline 3 root dev ramO Comments console ttyS0 9600 in common bootline This ensures that for all Kernel images commonly a serial console with 9600 Bd on ttySO is supported root dev hdcl root dev hdal Configuration of a mass storage device CompactFlash IDE for the root fs root dev ram0 Root file system is INITRD From kernel 2 6 17 the root filestem can be includet to the kernel image in this case the root
6. 1Processor Setup for the Kontron Target CPUs For each board supported in a BSP a default setting is provided The way of how this default setting is loaded is described in the previous chapter This default setting already provides a correct set up for the devices onboard the target system e g an E Brain module with the appropriate carrier or a CompactPCI or VME Board This means that the following onboard devices are already preconfigured correctly eCPU type and options econsole typically serial console optional graphics controller enetwork drivers eserial drivers eonboard mass storage devices e g CompactFlash However there are kernel options which must be set depending on the application The most important are mentioned in the following paragraphs 11 1 2Kernel Command Line The Kontron NetBootLoader can pass a kernel command line to the Linux kernel by the cbl command ID 29331 Rev 07 2007 Kontron Modular Computers Page 19 Embedded Linux 2 6 User Manual Calling help on the NetBootLoader command prompt will display this message Display all valid bootlines cbl Delete a bootline cbin Change Overwrite a bootline cbl n lt args gt n may be c or 0 3 Refer to the hardware manual for a detailed description of the cbl command This feature is not available for bootloaders other than the Kontron NetBootLoader e g the U Boot The kernel concatenates the ecommon command line cbl c command on NetBootLoa
7. a bigger or smaller RAM disk image or to use a different kind of file system a new INITRD image must be created First create an empty image This is done with the commands root x86host dd if dev zero of ramdisk image bs 1024 count 16384 16384 0 records in 16384 0 records out root x86host sbin mkfs ext2 ramdisk image mke2fs 1 38 30 Jun 2005 ramdisk image is not a block special device Proceed anyway y n y Filesystem label OS type Linux Block size 1024 log 0 Fragment size 1024 log 0 4096 inodes 16384 blocks 819 blocks 5 00 reserved for the super user First data block 1 2 block groups 8192 blocks per group 8192 fragments per group 2048 inodes per group Superblock backups stored on blocks 8193 Page 30 2007 Kontron Modular Computers ID 29331 Rev 07 Writing inode tables done Writing superblocks and filesystem accounting information done This filesystem will be automatically checked every 39 mounts or 180 days whichever comes first Use tune2fs c or i to override The command dd creates an empty file with a size matching the space which shall be available for the ramdisk in the above example it is 16384 1024 16 MB The mkfs ext2 command then creates an ext2 file system within this file However any other file system type could be used alternatively if desired Refer to the documentation for dd mkfs for more details on the arguments for these commands Now create a temporary directory fo
8. build the demo applications usr x86host gt make demoapps Build the demo applications Optionally not available in all BSP s usr x86host gt make lm sensors Build all the user space applications contained in the Im sensors package Optionally not available in all BSP s usr x86host gt make thirdparty Build additional 3 party drivers which are provided within the BSP This component only exists if the board is equipped with particular HW components for which 3 party drivers not integrated in the kernel are required If this rule doesnt exist all HW components are fully supported within kernel and the Kontron board drivers Finally to clean up everything call usr x86host gt make clean 10 5 Install the BSP components The building process described in the previous chapter generates various binary exectubles kernel modules and shared libraries To execute these on the target they have to be copied to the desired location in the target root file system There are various ways to generate a target root file system please refer to the according chapters below so there is no possibility to do that fully automatically within the Makefile But just by calling usr x86host gt make install All generated output files are installed into the sub directory boot within the current working directory already in the correct directory hierarchy as you could also find in the target root fs So it is up to the user t
9. c Modify kernel configuration The kernel is already configured correctly for the Kontron board supported For most applications this default configuration will be correct At least for the first tests it is highly recommended to build the kernel with this default configuration Information for Advanced Users This kernel supports the standard kernel configuration mechanisms make menuconfig and make xconfig However the various configuration options of a Linux kernel will not be described in this document d Build kernel Call the following command to build dependencies and the kernel image for Kernel 2 6 bspwork sample project linux gt make Page 16 2007 Kontron Modular Computers ID 29331 Rev 07 10 4 Compile the BSP components Before any build dont forget to source the environment sh script bspwork sample project gt source scripts environment sh Setting KOMKERNELDIR to home lt username gt bspwork sample project linux Setting KOMINSTALLDIR to home lt username gt bspwork sample project boot Kernel Version lt kernel version gt After this the system is prepared for compilation To compile all components just call in lt work_dir gt usr x86host gt make The particular components of the BSP can also be built separately with the commands usr x86host gt make kernelmodules Compile all kernel modules provided in the BSP usr x86host gt make userlib Create the board library which is required to
10. looks like this root x86host home usr bsp work ramdisk work ls 1 mntloop total 20 drwxr xr x root 1000 1024 2005 02 23 12 32 proc drwxr xr x root 1000 1024 2005 03 08 17 40 sbin drwxr xr x root 1000 1024 2005 02 23 17 23 usr root x86host home usr bsp work ramdisk work drwxr xr x 10 root root 1024 2005 03 08 18 17 drwxr xr x 3 root root 136 2005 03 09 10 48 drwxr xr x 2 root 1000 1024 2005 03 08 17 36 bin drwxr xr x 2 root 1000 1024 2005 02 23 12 32 dev drwxr xr x 3 root 1000 1024 2005 02 23 12 32 etc drwxr xr x 2 root 1000 1024 2005 03 08 18 08 lib lrwxrwxrwx 1 root root 11 2005 03 08 18 17 linuxrc gt bin busybox Grise 2 root root 12288 2005 03 08 18 16 lost found 2 2 4 The entire root file system which was hidden previously is visible now It is possible to inspect or modify the contents of such a file system With the tool df h it is also possible to check the free space on the mounted RAM disk image root x86host home usr bsp work ramdisk work df h Filesystem Size Used Avail Use Mounted on home usr bsp work ramdisk work ramdisk imagenew 3 4M 3 2M 3 0K 100 home usr bsp work ramdisk _ work mntloop The file system may be modified according to the application requirements e g add applications which where cross compiled for this hardware Once the file system has been modified it must be converted back to an updated ramdisk image gz file and stored back into the kernel This is achieved with the
11. much higher This should be taken into consideration when purchasing a CompactFlash device This restriction does not apply to the IBM Microdrives Page 26 2007 Kontron Modular Computers ID 29331 Rev 07 12 3IDE HDD Some Kontron targets can be equipped with an IDE HDD Some have the IDE controller and connector on the baseboard E Brain some others provide open interfaces for IDE extensions e g the PMC Slot on CompactPCI boards which can be equipped with the Kontron PMC HDD1 extension IDE HDDs provide a cost effective way to add substantial mass storage capacity Advantages ebroad range of memory capacities ecost effective efast data transfer via DMA Restrictions enot suitable for applications where mechanical drives are not feasible 12 4SCSI Drives Kontron boards with a PMC slot can be optionally equipped with a SCSI adapter e g Kontron PMC260 Advantages ebroad range of memory capacities ecost effective efast data transfer via DMA Restrictions enot suitable for applications where mechanical drives are not feasible 12 5M Systems Disk On Chip Some Kontron PowerPC CPUs e g CP320 CP321 VMP1 and VMP2 support adding an M Systems Disk On Chip to the onboard DIP socket Advantages emulates a block device epartitions can be modified with the standard Linux tools fdisk mke2fs edriver integrated wear levelling for increasing the flash lifetime Restrictions ecompatibility problems
12. of this file Then it is possible to modify the file without damaging the installed BSP example usr x86host gt cd apps src usr x86host gt scripts make private sh wd demo c This replaces the wd_demo c symbolic link with a local copy of the file and now it can be modified The original file however is still available in the BSP install dir for this reason at any time a new and clean project copy of the BSP can be generated by calling initproject sh again Page 18 2007 Kontron Modular Computers ID 29331 Rev 07 11The Linux Kernel 11 1Kernel Configuration This chapter explains how the kernel can be customized for the particular needs of an application If this is being done for the first time then it is better to proceed with 10 3 Linux Kernel build and return here only after a kernel has been compiled and downloaded to the target Please note also that this document only shows a few particular items of the kernel configuration which may be useful for Kontron boards This document is not intended to describe all the configuration features of the Linux 2 6 kernel There are several ways to enter the kernel configuration make menuconfig menu driven text mode requires Ncurses make xconfig graphical user interface requires X and TCL TK make gconfig graphical user interface requires GTK Lib Independent of the type of configuration GUI chosen always the same configuration options will appear 11 1
13. root file system filesystem lt index gt ethe cross toolchain toolchain lt index gt All components can be found inside the directory for the particular architecture family as described above All packages are delivered in RPM format and additionally as a tarball a RPM Package Installation The RPM package is installed as root user with the following command usr x86host gt su Password xxxxx root x86host rpm ivh lt filename of rpm package gt e g root x86host rpm ihv bsp cp620 kom 2 6 10 0100 rpm root x86host rpm ihv crosstool powerpc 6xx linux gnu noarch rpm root x86host rpm ihv rootfs ppc 6xx kom 0102 noarch rpm The RPM package format provides the advantage that all of the installed packages are managed in a database So it s always possible to keep track of all installed packages To view all the Kontron packages installed on the system enter root x86host rpm qa grep kom bsp eb8540 kom 2 6 10 0100 bsp eb405 kom 2 6 10 0100 Information about individual packages may be obtained via rpm qi e g root x86host rpm qi bsp eb8540 kom To determine where the package files were installed enter root x86host rpm ql bsp eb8540 kom ID 29331 Rev 07 2007 Kontron Modular Computers Page 9 Embedded Linux 2 6 User Manual This will call up a list of all files belonging to this package Information for Advanced Users To learn more about the advantages of the RPM package format ref
14. target root filesystem mknod dev ixNpe c 241 0 insmod ixp400 ko ID 29331 Rev 07 2007 Kontron Modular Computers Page 59 Embedded Linux 2 6 User Manual cat IxNpeMicrocode dat gt dev ixNpe insmod ixp400 eth ko These commands have been integrated into the starting scripts of theLinux GPL Root Filesystem These scripts assume that the modules listed above exist in the root directory of the target root filesystem Now the Ethernet interfaces are started and running but they are not configured Before using them they should be configured using ifconfig linux tool The command ifconfig a dummy 0 Link encap Ethernet HWaddr F6 03 38 D4 27 EB BROADCAST NOARP MTU 1500 Metric 1 RX packets 0 errors 0 dropped 0 overruns 0 frame 0 TX packets 0 errors 0 dropped 0 overruns 0 carrier 0 collisions 0 txqueuelen 0 RX bytes 0 0 0 b TX bytes 0 0 0 b etho Link encap Ethernet HWaddr 00 02 B3 01 01 01 BROADCAST MULTICAST MTU 1500 Metric 1 RX packets 0 errors 0 dropped 0 overruns 0 frame 0 TX packets 0 errors 0 dropped 0 overruns 0 carrier 0 collisions 0 txqueuelen 256 RX bytes 0 0 0 b TX bytes 0 0 0 b eth1 Link encap Ethernet HWaddr 00 02 B3 02 02 02 BROADCAST MULTICAST MTU 1500 Metric 1 RX packets 0 errors 0 dropped 0 overruns 0 frame 0 TX packets 0 errors 0 dropped 0 overruns 0 carrier 0 collisions 0 txqueuelen 256 RX bytes 0 0 0 b TX bytes 0 0 0 b lo Link encap Local Loopback inet addr 127 0 0 1 Mask 255 0 0
15. tree Boot image from address 0 Command fdt_show print actually generated Flattened Device Tree 9 1 1NetBootLoader Documentation Refer to the board s hardware manual documentation for details A summary of how to use the NetBootLoader for downloading a Linux kernel to the Kontron target is provided here Hint The command help displays a help menu for all implemented commands NetBtLd gt help 9 1 2Prerequisites for Using Network Capabilities The following actions must be completed prior to using the network ea network cable 10 100 Mbit s must be attached to the PowerPC s primary Ethernet port ean FTP server must be running on the development host see the appropriate documentation for inetd conf ftpd in ftpd for details on how to install and configure an ftp server ethe network parameters must be assigned to the target This is done with the command nef NetBtLd gt help net Syntax Display change network settings net lt ip addr gt netmask lt netmask gt gw lt gateway gt f lt ip addr gt lt netmask gt lt gateway gt aa bb cc dd f force CRC update If the IP address netmask or gateway is not known request the system administrator to provide them This needs to be done only once for the target These parameters are stored in a serial flash EPROM Once these parameters have been changed the system must be restarted Page 12 2007 Kontron Modular Computers ID 29331 Re
16. usr bsp work ramdisk work umount mnttmp root x86host home usr bsp work ramdisk work gzip ramdisk image To be able to add ramdisk image gz to the kernel it has to be copied to the appropriate location root x86host home usr bsp work ramdisk work cp ramdisk image gz lt kerneldirectory gt arch lt architecture gt boot images ramdisk image gz For XScale based boards please refer to Appendix C XScale IXP42x based eBrain specific considerations ID 29331 Rev 07 2007 Kontron Modular Computers Page 31 Embedded Linux 2 6 User Manual 14 2 2Inspecting and Modifying an Existing INITRD Image The previous chapter showed how a new INITRD image can be created and filled with the contents of the provided GPL root file system A common task for an application programmer will be to modify this existing image by adding own files e g self developped applications or remove unused components To do this the existing ramdisk image gz first has to be unzipped root x86host home usr bsp work ramdisk work gunzip lt ramdisk image gz gt ramdisk imagenew Now it can be mounted via the loop device root x86host home usr bsp work ramdisk work mkdir mntloop root x86host home usr bsp work ramdisk work mount t auto o loop ramdisk imagenew mntloop Now the RAM disk image is mounted to the directory mntloop Enter the command to list its contents root x86host home usr bsp work ramdisk work ls 1 mntloop and the output
17. with the correct toolchain and use the correct runtime libraries 19 1Application List and Command Reference Detailed help on all Linux commands can be found in the file system installation directory optlinux26_bsp_kom rootfs_ lt architecture gt _ lt subarchitecture gt lt version gt doc The cover sheet index html within this document provides information about all available Linux programs and links to the command references of the particular commands Information for Advanced Users Additionally the sources of this GPL root file system are enclosed on the CD ROM under the directory GPLSOURCES The sources are delivered under the GPL without any warranties or support 19 2Directory structure One of the final operations performed by the Linux kernel during system boot up is the mounting of the root file system The root file system is an essential component of all Linux systems Each top level directory in the root file system has a specific purpose bin commands required during boot up and the tools for use by normal users sbin like bin but the commands are not intended for normal users although they may use them if necessary and allowed letc configuration files root the home directory for root user Nib shared libraries needed by the applications lib modules loadable kernel modules in subdirectory fitting to Kernel version uname r Idev device files proc mount points for the proc file system usr secondary hierarchy
18. 234 bin primes Process bin primes created pid 148 On the development host now start ddd instead of the powerpc linux gdb But ddd must know that it should use the powerpc linux gdb as the inferior debugger ddd is a program that is indifferent to the hardware specific details It always uses an underlying command line debugger to perform the hardware relevant job The command line to start ddd is usr x86host gt ddd debugger powerpc linux gdb bin primes amp ddd debugger lt path to debugger gt powerpc linux gnu gdb bin primes ID 29331 Rev 07 2007 Kontron Modular Computers Page 45 Embedded Linux 2 6 User Manual This will open a screen similar to this On the first occasion that ddd is started for cross debugging go to the menu Edit GDB Settings Move to the items architecture of target and endianness of target Normally these two items are set to auto per default The target architecture should be detected correctly in this mode In any case this should be verified by clicking on the sign Page 46 2007 Kontron Modular Computers ID 29331 Rev 07 The output should look as follows DDD Help If this is not the case the architecture powerpc common and endianness big endian will need to be manually configured here After exiting this menu choose Edit Save Options to make the modifications permanent Now debugging with ddd can be performed For help with ddd refer to the d
19. Block size 1024 log 0 Fragment size 1024 log 0 6000 inodes 23996 blocks 1199 blocks 0 00 reserved for the super user Page 38 2007 Kontron Modular Computers ID 29331 Rev 07 First data block 1 3 block groups 8192 blocks per group 8192 fragments per group 2000 inodes per group Superblock backups stored on blocks 8193 Writing inode tables done Writing superblocks and filesystem accounting information done This filesystem will be automatically checked every 23 mounts or 2 11367e 314 days whichever comes first Use tune2fs c or i to override 17 4Preparation of the Root File System on the Disc On Chip To prepare the DOC for the root file system installation perform the following eplug the Disc On Chip device into the board boot the system as described in 12 6 ys required for booting emount the drive ecopy the root file system package which is provided in the BSP to the exported via NES directory mounted as a root file system by the target board eunpack the root file system which is provided in the BSP to the Disc On Chip root target mount dev nftla1i mnt root target cd mnt root target tar preserve permissions xvjf path to rootfs package root_ filesystem lt arch gt lt subarch gt linux tar bz2 umount the Disk On Chip device econfigure the kernel command line with root dev nfilal download this new kernel and reboot 18Cross Development For application development and debugg
20. D driver which works correctly with the Kontron PowerPC CPUs and the Disk On Chip 17 2Kernel Configuration For all Kontron boards with a Disk On Chip socket onboard the support for this device is already activated in the provided Kernel default configuration 17 3Creating Partitions In typical applications the Disk On Chip will be used very often to store the root file system To achieve this first an appropriate file system must be installed on the Disk On Chip The following command line when run on the target system will return the contents partitions of the installed DOC device root target ls dev nftla dev nftla dev nftlat1 The example results show two files dev nfila and dev nfilal The nfila file represents whole DOC device the nftlal file represents the partition already existing on the device If there is no partition on the device there will be only the disc file in the result Use the fdisk utility to remove any existing partitions and create the new one as needed The fdisk utility should be invoked with root target fdisk dev nftla For details about usage of the fdisk utility see its manual page After the partition is created and changes are written to the disc the partition must be formatted with the requested file system type For example Formatting the partition with ext2 filesystem root target mkfs ext2 dev nftla1 mke2fs 1 36 05 Feb 2005 Filesystem label OS type Linux
21. G kontron LINUX 26 BSP Kontron Embedded Linux 2 6 User Manual Manual ID 29331 Rev Index 07 May 2007 The product described in this manual is in compliance with all applied CE standards Embedded Linux 2 6 User Manual 1Copyright Copyright 2005 2007 Kontron modular Computers Kontron Modular Computers makes no representations or warranties with respect to the contents or use of this manual and specifically disclaims any express or implied warranties of merchantability or fitness for any particular purpose Kontron Modular Computers makes no representations or warranties with respect to this embedded Linux package and specifically disclaims any express or implied warranties of merchantability or fitness for any particular purpose Permission is granted to make and distribute verbatim copies of this manual provided that the copyright notice and this permission notice are preserved on all copies Permission is granted to copy and distribute modified versions of this documentation under the conditions for verbatim copying provided also that the entire resulting derived work is distributed under the terms of a permission notice identical to this one Permission is granted to copy and distribute translations of this documentation into another language under the above conditions for modified versions Intel and Pentium are a trademarks or registered trademarks of Intel Corporation or its subsidiaries in the United States
22. Not all Disk On Chip devices are compatible with all Kontron PowerPC CPUs Contact the Support department for further information regarding the compatibility of Disk On Chip devices For detailed information refer to 17 Root File System on an M Systems Disk On Chip 12 6Remote File System on an NFS Server ID 29331 Rev 07 2007 Kontron Modular Computers Page 27 Embedded Linux 2 6 User Manual Besides the physical mass storage devices described above a kind of virtual mass storage device can be mounted via NFS Advantages eno external storage media necessary every convenient during the debugging phase of an application eremote debugging is possible emodifications on the root file system performed on the NFS server are immediately visible for the target no specific download necessary Restrictions enot a stand alone solution server is always required for booting For detailed information refer to 12 6 ys required for booting 13Setting Up a Diskless Client A very convenient way for application cross development is to setup the Kontron target as a diskless client which mounts the root file system via NFS on the development host All application programs which are cross compiled on the development host are immediately available on the target system No download or target reboot is required Additionally the remote debugging facility of the gdb debugger with or without the graphical frontend ddd can be used
23. and other countries Linux is a registered trademark of Linus Torvalds SuSE is a registered trademark of SuSE GmbH RedHat is a registered trademark of RedHat All other trademarks registered trademarks and trade names are the property of their respective owners Page 2 2007 Kontron Modular Computers ID 29331 Rev 07 2Revision History Manual Product Title LINUX 26 BSP PPC Manual ID Number Revision Index Brief Description of Changes Date of Issue Added chapter about cross development April 2005 Some additional clarifications May 2005 improvements Added subchapter about compiler options and June 2005 possible influence on performance Added chapter describing the GPL root file system fits to filesystem 0102 or newer development etc UDEV description chapter Xscale specific appendix grammar and style corrections Included PDR 06025237 solution for problem with shared libraries symbols when cross debugging Added information valid for BSP EB8347 May 2007 05 Added chapter about User Project creating May 2006 07 ID 29331 Rev 07 2007 Kontron Modular Computers Page 3 Embedded Linux 2 6 User Manual 3Contents 12 Root Fil System SACS amenant uinauauediedeel 26 12 1 Onboard FLASH INITRD RAMES nine ee nd monde du ten 26 Page 4 2007 Kontron Modular Computers ID 29331 Rev 07 17 4 Preparation of the Root File System on the Disc On Chip 39 18 Cross Devel
24. ation Inc GDB is free software covered by the GNU General Public License and you are welcome to change it and or distribute copies of it under certain conditions Type show copying to see the conditions There is absolutely no warranty for GDB Type Show warranty for details This GDB was configured as host i686 pc linux gnu target powerpc linux gnu PowerPC remote debugging configured The target is assumed to be big endian Ox3000f1b0 in gdb Page 44 2007 Kontron Modular Computers ID 29331 Rev 07 The target will be immediately connected This is visible on the target shell with the message Remote debugging using aaa bbb ccc ddd 1234 and debugging can begin 18 5Graphical Debugging Migrating from the gdb command line interface to the ddd GUI is an easy step because ddd is just a graphical front end for the gdb The low level debugging task is still performed by gdb Requirements command line remote debugging with gdb as described in the previous chapter must work correctly eddd debugger is installed on the development host ddd is contained in most of desktop distributions e g SuSE Fedora Red Hat ethere is a file gdbinit in the current directory as described above this is not mandatory but more convenient The debugging can be started as follows On the target command line it is the same as described in the previous chapter usr target target bin gdbserver aaa bbb ccc ddd 1
25. commands root x86host home usr bsp work ramdisk work umount mntloop root x86host home usr bsp work ramdisk work gzip ramdisk imagenew root x86host home usr bsp work ramdisk work cp ramdisk imagenew gz lt kerneldirectory gt arch lt architecture gt boot images ramdisk image gz For XScale based boards please refer to Appendix C XScale IXP42x based eBrain specific considerations Page 32 2007 Kontron Modular Computers ID 29331 Rev 07 14 3Adding an INITRD to the Kernel The previous chapters explained how an INITRD is generated Now this INITRD shall be bound to the Kernel image in a way that it can be programmed to the onboard flash and booted together with the Kernel To achieve this the following has to be done 14 3 1Kernel Configuration For INITRD support the following options must be set in the Kernel configuration Device Drivers Block devices lt gt RAM disk support 16 Default number of RAM disks NEW 4096 Default RAM disk size Initial RAM disk initrd support image before compression Example ifthe 16MB large has been created the Default RAM disk size should be configured for at least 16MB INITRD image If the RAM disk size is too small an error will be generated at kernel start i Please note that the Default RAM disk size option refers to the size of INITRD The INITRD is also formatted similar to a mass storage to one of supported in Linux file system types e g e
26. containing most applications useful to most users var variables data store by demons and utilities home root of the user home directories Page 50 2007 Kontron Modular Computers ID 29331 Rev 07 19 3Linux System Configuration Files The etc directory contains configuration files They are described below letc rc d scripts or directories including scripts running at startup or when changing the runlevel etc passwd user passwords database The format is documented in the passwd manual page man passwd etc fstab lists the file systems to be mounted automatically at startup man fstab etc group similar to etc passwd but describes groups instead of users Refer to the group manual page for more information man group etc inittab configuration file for init This file format is described within the busybox man page etc inet conf configuration file for inetd processes etc mtab list of currently mounted file systems etc shadow shadow password file on systems with shadow password software installed etc profile files executed at login or startup time by shell These files allow the system administrator to set global defaults for all users Refer to the manual pages for the respective shells 19 4 Device files In the Linux operating system communication with every device is realized by using device files These are special files in the dev directory The device file has following characteristics Device
27. dd online Help or the manuals available for ddd ID 29331 Rev 07 2007 Kontron Modular Computers Page 47 Embedded Linux 2 6 User Manual 18 6Execution Performance The right selection of GCC compilation options has a very high impact on the performance Note that some of the options may force the compiler to omit implementing some checking safe features to output code Here are list of options that should be used to achieve good performance OPTION DESCRIPTION fomit frame pointer Removes the frame pointer for all functions which might make debugging more difficult funroll loops Unroll loops when number of interations may be determined during compilation fforce mem Force memory operands to be copied into registers before doing arithmetic on them falign loops n Align start of loop to next power of n skipping up to n bytes falign functions n Align start of function to next power of n skipping up to n bytes falign jumps n Align start of places to jump into to next power of n skipping up to n bytes ffast math Causes _FAST MATH _ macro to be defined This may result in incorrect output for programs that depend on an exact implementation of IEEE and ISO rules msoft float Generate output containing library calls for floating point for FPU less machines A complete description of these features may be found in the manual for the gcc compiler 18 7PowerPC e500 Specific Optimiza
28. dded Linux target and an unformatted hard drive connected to it How is it possible to install a Linux root file system to the hard drive 16 4 1Preparation of the Root File System on the Development Host In case of a removable media CompactFlash one possible procedure is as follows eattach the empty CompactFlash to the development host using a CompactFlash card reader USB PCMCIA ecreate a file system on the CompactFlash as required With some file systems endianess problems can arise In particular if the mkfs xxx program is called on a little endian machine and then an attempt is made to mount this file system on a big endian machine However most file systems can handle this Still it may be necessary to determine this empirically emount the CompactFlash on the development host eunpack the root file system which is provided in the BSP to the CompactFlash root x86host mount lt compact flash device gt mnttmp root x86host cd mnttmp root x86host tar preserve permissions xvjf opt linux26 bsp kom rootfs lt arch gt lt subarch gt lt version gt root filesystem lt arch gt lt subarch gt linux tar bz2 econfigure the kernel command line with root dev lt compact flash device gt download this new kernel and reboot 16 4 2Preparation of the Root File System on the Target For non removable devices or to totally exclude endianess problems the following method is also possible eattach the IDE or SCSI disk to
29. ddf2 data type conversions float to double signed int to double unsigned int todouble signed long long to double unsigned long long to double double to float double to signed int double to unsigned int double to signed long long double to unsigned long long 1 3 2 The following math functions are supported floating absolute value fabs Square root sqrt Sine Sin cosine cos nearest integer rounding ceil floor exponent exp logarithm log log10 power pow arctangents atan atan2 fractional and integer decomposition modf floating point remainder fmod Better performance with an e500 core can also be achieved by including Wa me500 compiler options to the build process ID 29331 Rev 07 2007 Kontron Modular Computers Page 49 Embedded Linux 2 6 User Manual 19Linux GPL Root File System The Linux GPL root file system package includes many common utilities in a single small root directory tree It provides most of the utilities usually found in GNU coreutils util linux etc The previous chapters regarding root file system strategies already described how to install this root file system on the target This chapter provides a brief overview about the contents of this root file system The GPL root file system is provided on the CD ROM in a ready to use binary format for every supported architecture family The binary format ensures that the Linux programs are already compiled
30. ddresses are located properly for the Kontron target The generated file s are found in arch lt architecture gt boot images arch lt architecture gt boot images zImage kom pure kernel image or arch lt architecture gt boot images zImage initrd kom kernel image including an initial ramdisk The generated kernel image can now be downloaded to the Kontron target 11 2 Network Download Ensure that the system is set up in accordance with chapter 9 1 2 Prerequisites for Using Network Capabilities First the zImage kom or zImage initrd kom must be copied to a location where the target can access it via FTP After compiling the kernel enter gt cp arch lt architecture gt boot images zImage kom home targetuser on the development host s command line Now reset the target when the prompt appears immediately enter abort or press the abort button NetBtLd gt abort Now an FTP connection to the development host can be opened with the command NetBtLd gt login hosts ip address lt username gt lt password gt The response should be similar to this NetBtld gt login lt server IP address gt targetuser targetpasswd 220 develop host FTP server Version 6 5 OpenBSD linux port 0 3 2 ready 331 Password required for targetuser 230 Have a lot of fun 230 User targetuser logged in Successfully logged in This ftp client supports the commands put get Is pwd bye To download a Linux kernel zImag
31. der ethe image specific command line cbl fimagenumber command on NetBootLoader and uses the resulting string as its kernel command line Alternatively the kernel command line can be configured and compiled into the kernel This will be the only solution to provide a command line if using the U Boot loader or it might be desired to hardcode the commandline into the kernel for any reason The kernel command line is configured in the menu Platform options gt Default bootloader kernel arguments The compiled in command line is only active if no command line is passed by the boot loader The bootloader command line will always overwrite the compiled in command line For XScale based boards please refer to Appendix C XScale IXP42x based eBrain specific considerations The resulting command line is always visible on the kernel startup as shown in the following example loaded at 00000100 00116298 relocated to 00800000 00916198 board data at 00914030 00914098 relocated to 00805290 008052F8 zimage at 00805B19 00913A95 avail ram 00917000 08000000 Linux PPC load console ttyS0 9600 ip 193 102 136 44 193 102 136 43 193 102 136 43 255 255 255 0 eb8347 eth1 root nfs nfsroot nfsroot claugi eb8347 Uncompressing Linux done Now booting the kernel Linux version 2 6 13 rc6 claugi claugisuse10 gcc version 3 4 1 3 Tue Mar 28 15 19 09 CEST 2006 Built 1 zonelists Kernel command line console ttyS0O 9600 ip 193 102 136 44
32. e documentation on the RPM web site www rpm org In addition Maximum RPM by Edward C Bailey is another great source for detailed information about the many powerful options available with RPM www redhat com support books max rpm max rpm html index html Page 56 2007 Kontron Modular Computers ID 29331 Rev 07 23Appendix B Configuring Minicom To configure minicom follow these steps a Log in as root and run minicom S The minicom configuration menu appears b Select serial port set up and set the options for the target A Serial Device dev ttySx select the port of the host B Lockfile Location var lock E Bps Par Bits 9600 8N1 F Hardware Flow Control No G Software Flow Control No Press Enter to return to the main configuration menu d Select modem and dialling Erase the values for A Init string B Reset string and K Hang up string Press Enter to return to the main configuration menu e Save values and exit Select Save as dfl to save these as the default settings Select Exit from Minicom f Go back to normal user mode Now leave the root login From a users command prompt enter minicom NOTE Usage of minicom may require certain permissions On some distributions it might be necessary to be a member of the uucp group to access serial ports Refer to the manual of the Linux distribution or query the system administrator ID 29331 Rev 07 2007 Kontron Modula
33. e enter the command ID 29331 Rev 07 2007 Kontron Modular Computers Page 23 Embedded Linux 2 6 User Manual NetBtLd gt get zImage kom The response should be similar to this 200 200 200 200 150 226 Type set to I STRU F ok MODE S ok PORT command successful Opening BINARY mode data connection for zImage kom Transfer complete Data loaded count 561924 Now the kernel image is downloaded to the target system Page 24 2007 Kontron Modular Computers 561924 bytes ID 29331 Rev 07 The next step is to program it to the onboard flash with the command lf NetBtLd gt lf When the prompt appears the system must be rebooted with NetBtLd gt rs This kernel image is programmed into a flash ROM This means that it can never be lost even without any batteries It can only be deleted by a new download The image is secured with a CRC so that the boot loader can verify the integrity of the flash contents at every system startup before unpacking and starting the kernel image For quick testing start the image directly from RAM without flashing it In this case use the command run just enter NetBtLd gt run The kernel image starts immediately After the next reboot the image is lost and must be downloaded from the server again 11 3Booting If the command run has been entered the kernel will immediately boot If the target was flashed with If followed by a system reset command rs or pressing
34. er to Appendix A Notes on RPM After the Kontron RPM packages are installed on the development host the following directories exist in the opt directory opt crosstool lt architecture gt linux gnu GNU cross compiler toolchain kernelver bsp kom The BSP bsp_ boardname 3rd party drivers Optional other parties software lm sensors Optional the Lm sensors source package linux Linux kernel source scripts useful scripts apps target applications inc target header files lib API library addl libs Additional libraries e g sysfsutils pciutils sources all sources are provided rootfs lt architecture gt _ subarch version the linux root file system docs command reference a binary image of the root file root_filesystem_ lt architecture gt _ subarch linux tar bz2 system b Tarball Installation The RPM installation is the preferred method Tarballs are provided for Linux distributions not supporting RPM Tarballs are extracted with tar commands etar xvjf lt filename gt for archives with the extension tar bz2 or etar xvzf lt filename gt for archives with the extension tar gz or tgz Refer to the Linux man pages for further information on how to extract tarballs Makefiles will only work if the tars are extracted to the same locations as described eo In principle tarballs may be extracted to any location But the provided scripts and above in paragraph RPM i
35. ferent kind of root file system e g a root fs which was provided by a commercial embedded Linux distribution it might happen that these libraries and headers are not compatible with this root file system In this situation the libraries and headers of this distribution shall be used instead eThe Im sensors package within this BSP also links against the libsysfs within this addl libs directory If you are using a different kind of root file system e g a root fs which was provided by a commercial embedded Linux distribution you might run into compatibility problems In this case the libraries and headers of this distribution should be used instead Information for Advanced Users i For more informations regarding the libraries contained in addl_libs and for their usage please refer to the project home pages of sysfsutils and pciutils or look into the Kontron GPL root fs source package where this packages are contained as full tarballs ID 29331 Rev 07 2007 Kontron Modular Computers Page 53 Embedded Linux 2 6 User Manual 21The LM Sensors package optional Some BSP s provide the LM Sensors package for system monitoring This package is integrated into the BSP in a way that it can be easily cross compiled for the particular supported Kontron HW see 10 4 Compile the BSP components And the kernel is already configured for LM Sensors support for all devices contained on this board However LM Sensors is a mighty packa
36. ge for HW monitoring The created directory structure is based on symbolic links to the original files within the installed BSP This has the advantage that creating such a project environment requires a very small amount of disk space and as a 2 effect that the BSP provided files can not be unintentionally modified Page 14 2007 Kontron Modular Computers ID 29331 Rev 07 10 2 Setting the development environment Besides the directory structure initproject sh will generate a script called environment sh which sets up all required environment variables for the build process This means that it configures the Kernel source location and the compiler environment The environment sh script must be sourced before compiling any component of the BSP Additionally this environment script can be used for setting up the environment within own application projects So use the following command as the next step usr x86host gt cd lt work dir gt usr x86host gt source scripts environment sh example usr x86host gt cd bspwork eb42x project usr x86host bspwork eb42x project gt source scripts environment sh Setting KOMKERNELDIR to home usr bspwork eb42x project linux Setting KOMINSTALLDIR to home usr bspwork eb42x project boot Kernel Version 2 6 13 rc6 usr x86host bspwork eb42x project gt After this the system is prepared for compilation 10 3 Linux Kernel build The Kontron embedded Linux contains a Linu
37. ge needs other packages that are not present Querying Packages To determine if a package is installed type rpm q package name To obtain information about an installed package type rpm qi package name To list the files belonging to a package type rpm ql package name To determine a package in which a file is located type rpm qf path to filename One can usually join various query commands together For instance rpm qil will give information and list all the files in the package To view the contents of an RPM that is not installed add p to the query line rpm qilp somepackage 1 1 4 i386 rpm This will list the information and the files contained in the file somepackage 1 1 4 1386 rpm ID 29331 Rev 07 2007 Kontron Modular Computers Page 55 Embedded Linux 2 6 User Manual Verification RPM can also be used to see what files on the system may have changed from their initial settings To check all installed packages type rpm Va This will summon a list of all files that have changed since the packages were installed This can be a large number of files To see only what packages have changed so that they can be verified individually type rpm Va awk print 2 xargs rpm qf sort u amp gt tmp filel Then look in the file tmp file1 for the list of packages that have changed More Advanced Usage More advanced usage procedures can be found in the documentation for RPM and in th
38. ge with a rich feature set To create own applications using the LM Sensors API please refer to the online documentation contained within the Im_sensors source tree within the project working directory or look into the LM Sensors homepage at http secure netroedge com Im78 index html Page 54 2007 Kontron Modular Computers ID 29331 Rev 07 22Appendix A Notes on RPM RPM stands for the Red Hat Package Manager This is an open packaging system available for anyone to use RPM packages can be easily installed and tracked and the source can be easily reconstructed It also maintains a database of all packages and their corresponding files that can be used for verifying packages and to obtain information about files and packages The following is a quick primer for Red Hat s packaging system RPM To the RPM it is necessary to be the root user In general normal usage of the rpm command can be summarized as follows Package Installation and Removal To install a package issue the command rpm ivh filename To upgrade a package type rpm Uvh filename To remove a package type rpm e package name In order to upgrade or install some packages additional flags may be required Use these commands only if it is understood what they mean and how they can affect the system Some examples are force which will overwrite files that are owned by other packages and nodeps which will perform the installation even if the packa
39. hain opt crosstool lt architecture gt linux gnu gcc lt gcc version gt glibc lt glibc version gt lt architecture gt linux gnu lib Now load the symbols for the file to debug gdb sym bin primes Reading symbols from bin primes done Set breakpoints on line 28 and line 33 of the program gdb break 28 Breakpoint 1 at 0x10000414 file primes c line 28 gdb break 33 Breakpoint 2 at 0x10000460 file primes c line 33 Now execute the program until it reaches the first breakpoint gdb c Continuing Breakpoint 1 main at primes c 28 28 printf tThis program lists all primes lt n n n gdb Continue the program gdb c Continuing Now the prompt does not appear immediately The reason for this is that the program prompts for input This is visible in the target command line usr target bin gdbserver aaa bbb ccc ddd 1234 primes Process primes created pid 151 Listening on port 1234 Page 42 2007 Kontron Modular Computers ID 29331 Rev 07 ID 29331 Rev 07 2007 Kontron Modular Computers Page 43 Embedded Linux 2 6 User Manual After entering a number the command proceeds until it reaches the breakpoint in line 33 On the development host the gdb command prompt will appear again Breakpoint 2 main at primes c 33 33 for possible prime 2 possible prime lt n gdb Now the basic startup procedure of a remote debugging session should be clear Mo
40. ing the PowerPC target will typically mount the root file system via NFS There are no specific requirements for the root file system in this case but generally speaking usually it is not necessary to focus on keeping it very small 18 1Cross Compilation For cross compilation of user space applications the same cross development tool chain should be used as for Linux kernel As a base for cross compilation the Makefile provided in the target directory of the BSP may be used In this case to recompile all user space applications and kernel modules enter the following usr x86host gt cd target usr x86host gt source scripts SETENV sh usr x86host gt make Each of the BSP applications can be compiled also by hand A good example would be the primes application usr x86host gt mkdir temp usr x86host gt cd temp usr x86host gt source scripts SETENV sh usr x86host gt SCROSS COMPILE gcc g src primes c ID 29331 Rev 07 2007 Kontron Modular Computers Page 39 Embedded Linux 2 6 User Manual In this case the a out binary should appear in temp directory Note that primes c is a very simple application that does not need specific header files or libraries For other applications included in the BSP compilation is a little more complicated The g option in the command line causes the gcc to produce the debugging information in the binary file a out Without this information debugg
41. ing is impossible The binary file can be transferred to the target file system In case of an NFS based file system it can just be copied into an exported directory usr x86host gt cp a out nfsroot lt boardtype gt primes Now it can be executed on target system Please press Enter to activate this console BusyBox v1 00 2005 02 23 14 30 0000 Built in shell ash Enter help for a list of built in commands Processing etc profile Done primes This program lists all primes lt n Input n 10 Primes lt 10 NS I 01 WD Page 40 2007 Kontron Modular Computers ID 29331 Rev 07 18 2Debugging Tools gdb and gdbserver The most commonly used tool for debugging under Linux is the gdb debugger In the cross development environment gdb is divided into two parts eodbserver runs on the PowerPC target and controls the execution of the program being debugged eodb runs on the host and provides a command interface and access to symbol information and source code Both gdb and gdbserver are free software covered by the GNU General Public License To make things easier the program binaries are included in the BSP package These binaries are configured and tested for x86 host to PowerPC target cross debugging eodbserver is located under bsp_ lt boardtype gt target bin gdbserver eodb is located under bsp_ lt boardtype gt host bin powerpc linux gdb Note that this version of the gdb is specifically configured for cr
42. ions Type show copying to see the conditions There is absolutely no warranty for GDB Type Show warranty for details This GDB was configured as host i686 pc linux gnu target powerpc linux gnu ID 29331 Rev 07 2007 Kontron Modular Computers Page 41 Embedded Linux 2 6 User Manual gdb target remote aaa bbb ccc ddd 1234 Remote debugging using aaa bbb ccc ddd 1234 Ox3000f1b0 in gdb where eaaa bbb ccc eee is the IP address of the PowerPC target 01234 is the same port number as chosen in the gdbserver command line argument When cross debugging the gdb on the development host should be able to find the absolute and non absolute shared library symbol files The proper search paths are represented by gdb internal variables esolib search path the search path for loading non absolute shared library symbol files esolib absolute prefix prefix for loading absolute shared library symbol files These paths are configured in following way gdb set solib search path dev null gdb set solib absolute prefix lt path to the target libraries gt gdb In case if the root filesystem is exported by NFS server the path to the target libraries may be set as lt path to the exported root filesystem gt lib However if the target root filesystem is not exported by NFS server ex The root filesystem is installed on the CF device this path may point to the target libraries included in the cross development toolc
43. ired to enable the appropriate drivers in the kernel configuration 16 3PMC260 or CP360 Required Kernel Configuration For the Kontron SCSI controller PMC260 or CP360 please configure the kernel as follows Be sure to enable SCSI support in the kernel configuration and select the appropriate SCSI low level driver In the case of a PMC260 SCSI module this would be SCST Suppor ea gt lt gt SCSI support LH SCSI disk support NEW SCSI low level drivers gt lt gt SYM53C8XX SCSI support NEW After generating and downloading the kernel the SCSI hard drive should be detected by the Linux kernel During the boot process an output similar to this should be displayed SCSI subsystem driver Revision 1 00 sym53c8xx at PCI bus 0 device 20 function O sym53c8xx setting PCI COMMAND PARITY fix up sym53c8xx 53c895 detected sym53c895 0 rev 0x1 on pci bus O device 20 function O irq 3 sym53c895 0 NCR clock is 40037KHz sym53c895 0 ID 7 Fast 40 Parity Checking sym53c895 0 on chip RAM at 0x80204000 sym53c895 0 restart scsi reset sym53c895 0 Downloading SCSI SCRIPTS sym53c895 0 SCSI bus mode change from 80 to 80 sym53c895 0 restart scsi mode change sym53c895 0 Downloading SCSI SCRIPTS scsi0 sym53c8xx version 1 6b Vendor QUANTUM Model VIKING II 4 5WLS Rev 5520 Type Direct Access ANSI SCSI revision 02 Page 36 2007 Kontron Modular Computers ID 29331 Rev 07 16 4The Chicken Egg Problem Imagine an embe
44. kernel Linux will come up with the command line prompt RAMDISK Compressed image found at block 0 VFS Mounted root ext2 filesystem readonly Mounted devfs on dev Freeing unused kernel memory 104k init Please press Enter to activate this console eth2 Full Duplex eth2 Speed 100BT eth2 Link is up BusyBox v1 00 2005 02 23 16 12 0000 Built in shell ash Enter help for a list of built in commands Processing etc profile Done uname a Linux eb8540 initrd 2 6 10 rc3 3 Wed Mar 9 09 59 34 CET 2005 ppc unknown unknown GNU Linux Page 34 2007 Kontron Modular Computers ID 29331 Rev 07 15INITRAMFS RAMES is a very simple filesystem that exports Linux disk caching mechanisms as a dynamically resizable ram based filesystem It is very similar mechanism to INITRD but much simpler in use because it does not require the root privileges to build kernel image with root filesystem included More information is available in the kernel documentation in file Documentation filesystems ramfs rootfs initrams txt 15 1 1Kernel Configuration The initramfs is configured in kernel menu configuration in General setup section The menu entry Initramfs source files must contain a valid path to the root filesystem A ADD UD m ot Initramfs 15 1 2Kernel Command Line In the kernel command line the root device must not be configured 15 1 3Building a Kernel image with root filesystem in RAMFS To create a
45. kernel image including root filesystem in RAMFS just call ae Ps Oe a This will generate a file vmlinux gz or vmlinux bin in the subdirectory arch lt architecture gt boot 15 2Downloading and Booting Download the newly created kernel image as described in chapter 11 2 Network Download and in chapter 11 3 Booting ID 29331 Rev 07 2007 Kontron Modular Computers Page 35 Embedded Linux 2 6 User Manual 16Root File System on a Mass Storage Device IDE SCSI CompactFlash Some Kontron targets can be equipped with an IDE HDD Some have the IDE controller and connector on the carier E Brain others provide open interfaces for IDE extensions e g the PMC slot on CompactPCI boards which can be equipped with the Kontron PMC HDD1 extension IDE HDD provides a cost effective way to add substantial mass storage capacity Kontron boards with a PMC slot can be optionally be equipped with a SCSI adapter e g Kontron PMC260 Many Kontron targets are equipped with a CompactFlash socket onboard 16 1Required Kernel Configuration for CompactFlash For all Kontron boards with a CompactFlash socket onboard this controller is already activated in the kernel default configuration of the BSP 16 2Required Kernel Configuration for IDE For all Kontron boards with IDE controller onboard this controller is already activated in the kernel default configuration of the BSP For third party controllers it may be requ
46. lowing files can be found eREADME txt short description where to download the packages and how to compile the software econfig example configuration for build environment eautoconf h configuration for Intel Hardware Access Library In the scripts subdirectory of the BSP the script make3rd_party sh can be found This script performs all steps listed above The only required activity from the user is to download the required software packages and put them into the 3rd_party_drivers directory of the BSP Note that the downloaded packages may be copied to the project directory if it has been created as described in chapter 10 My First Linux Project this is the preferred way After the packages are put in the 3rd_party_drivers directory the make3rd_party sh script may be invoked from the project directory with the project directory path as a parameter e g usr x86host bsp project gt sh scripts make3rdparty sh home usr bsp project i The build process requires the configured kernel sources 24 1 3 Using the created modules After invoking the script make3rd_party sh three files have been created eixp400 ko the Intel Hardware Access Library kernel module eixp400_eth ko the Intel Ethernet ports kernel module eIxNpeMicrocode dat the microcode for NPE functional blocks These files must be downloaded to the target filesystem root directory Using these modules requires additional activities on the
47. n limitations or specific handling instructions for particular distributions are documented within the doc directory on the Kontron Linux CD ROM 7 2Target 7 2 1Hardware Kontron embedded Linux BSPs are available for a wide variety of boards e g PowerPC eF Brain EB8245 EB8540 EB8541 EB860 EB8347 eCompactPCI CP320 CP321 CP322 CP620 eVME VMPI VMP2 VMP3 Arm Xscale eE Brain EB425 EB420 7 2 2Software The Kontron embedded Linux BSP contains all software components required for the target ID 29331 Rev 07 2007 Kontron Modular Computers Page 7 Embedded Linux 2 6 User Manual 8Preparing the Host Development Environment 8 1Embedded Linux BSP Installation 8 1 1Contents of the Kontron Linux CD ROM The Kontron Linux CD ROM which is provided together with system components is always structured following the various hardware architectures supported e g enoarch packages which are not architecture dependent eppc_40x packages which are specific for PowerPC 40x architectures e g Kontron EB405 eppc_6xx packages which are specific for PowerPC 6xx architectures e g Kontron EB8245 VMP1 2 CP320 1 eppc_e500 packages which are specific for PowerPC e500 architectures e g Kontron EB8540 EB8541 VMP3 eppc_e300 packages which are specific for PowerPC e300 architectures e g Kontron EB8347 1386 i686 packages which are specific for Intel architectures Each directory contains sub directories in the follo
48. nstallation Page 10 2007 Kontron Modular Computers ID 29331 Rev 07 9Preparing the Development Target Refer to the hardware manual for the Kontron CPU board for guidance on how to set it up for booting In particular the chapter about the NetBootLoader provides important information regarding the downloading and starting of the Linux kernel Kontron boards are typically equipped with the NetBootLoader a boot loader which has integrated TCP IP support for downloading files and remote login via telnet On some boards especially custom specific designs there may be a different boot loader e g U Boot This manual is only applicable for NetBootLoader equipped CPUs For the initial communication with the target a serial interface must be established between the development host and the serial term connection of the Kontron PowerPC board using a null modem cable The next step is to set up a serial terminal program on the development host The minicom program is used throughout this manual To set up minicom refer to Appendix B Configuring Minicom or refer to the manual for minicom This serial communication will represent the target s system console for the NetBootLoader and the Linux kernel NetBootLoader and Linux kernel are also capable of handling consoles logged in via telnet but for the initial steps this serial connection is mandatory To verify that the serial console works enter the boot loader command mode No
49. o TCM scsssecccssseeccsssececssssecesssscccsssssccssssscesssssccsssssccsssssccsssssccsssssccsssssccssssscesssssseesess 39 19 3 Lin x System SN LE LD Fil S en sbdadd nenidmeadasand nah Sbabenatbakdaahl ats 51 19 4 Device files Sica ia nen a khan E 51 242 ARM XScal Linux Kernel 2h un die ideiatan iniaa 61 24 LR np EL en nn des eos nl 61 24 2 2 Kernel Command Line 61 24 2 3 INITRD with ARM Linux Kernel eee eeennsssss ses srsnnnnssssssssnnn 62 24 3 NES mounted Root file SYSTEM esnesssssesssseenensssssssssssssses 62 ID 29331 Rev 07 2007 Kontron Modular Computers Page 5 Embedded Linux 2 6 User Manual 4introduction This manual does not describe the Linux operating system Its usage requires some Linux experience with ebasics of the Linux operating system eGNU C compiler einstalling software on a Linux system esystem administration eLinux kernel configuration and compilation 5Components of the Kontron Embedded Linux The Kontron Linux CD ROM contains the following components for each particular supported hardware ea customized Linux kernel ea GNU cross compiler tool chain ea Linux root file system with the most important Linux tools edrivers function libraries tools demo programs for the Kontron specific onboard components such as E7PROMs LEDs Watchdog etc The purpose of this package is to provide all the basic functionality to write Linux applications for Kontron boards It is n
50. o copy the whole tree under the directory lt boot gt or only particular files to the target root fs manually How this can be done is described in later chapters ID 29331 Rev 07 2007 Kontron Modular Computers Page 17 Embedded Linux 2 6 User Manual 10 6 How to build own applications using the BSP Building the demo programs provided with the BSP will give a first look amp feel of the available functionality However the main aim of the BSP is to provide facilities for writing own applications by using the BSP API This is achieved with the following files escripts environment sh this script sets up the build environment Kernel source dir and compiler configuration and shall be sourced in every build environment lib bin lib lt boardname gt a this library contains the API as described in on line manual and should be always linked against user applications einc contains all header files which come with the BSP Additionally the Makefile in the apps directory and the demo program sources shall be considered as templates for building own applications 10 7 How to modify files provided in the BSP After initialisation the lt work_dir gt contains only symbolic links to the original BSP files Because the original files are owned by root it is not possible to modify any of them in the project directory However there is a script make_private sh provided It replaces the symbolic link to a BSP source file with local copy
51. of the reset button an LED on the front panel CompactPCI or VME or on the carrier E Brain will flash for about 5 seconds After this time the kernel will be booted unless the abort button is pressed or the abort command is entered on the command line On the minicom screen an output similar to the following will appear NetBtLd run loaded at 00000100 00122298 relocated to 00800000 00922198 board data at 0092002C 00920098 relocated to O08052F0O 0080535C zimage at OO805AE9 0091F4AA avail ram 00923000 10000000 Linux PPC load root dev nfs rw console ttySO 9600 nfsroot 192 168 3 13 home exp ip 192 168 3 139 192 168 3 13 192 168 3 2 255 255 255 0 ebrain8540 eth2 off Uncompressing Linux done Now booting the kernel Memory CAM mapping CAMO 256Mb CAM1 OMb CAM2 0Mb residual OMb Linux version 2 6 10 rc3 claugi acerclaugi gcc version 3 4 3 2 Wed Mar 9 09 00 14 CET 2005 and so on At this point Linux kernel is now running on the target However without a file system it is not possible to execute any kind of a Linux application on this system The next step is to install a root file system ID 29331 Rev 07 2007 Kontron Modular Computers Page 25 Embedded Linux 2 6 User Manual 12Root File System Strategies The Kontron embedded Linux supports various alternatives for mounting a root file system It is up to the user to decide which root file system strategy is best suited to the application requirements whe
52. ogether with the kernel into the target s onboard flash The kernel loader code detects the packed INITRD image if present and mounts it as the root file system INITRD is principally designed to allow system start up to occur in two phases first the kernel comes up with a minimum set of built in drivers and second additional modules are loaded from INITRD Depending on the size of the application the INITRD may be sufficient to hold the root file system and the application program This is an important feature especially for embedded systems In this case a Linux application may be downloaded and run without any additional external storage components For additional information about the INITRD refer to the file Documentation initrd txt in the kernel source tree 14 2How to Create or Modify an INITRD This chapter describes how to create an INITRD in the ramdisk image gz format which can be added to the kernel and programmed to the onboard flash then Prerequisites a The kernel of the development host must support the loopback device This means that the mount o loop option must be supported b Logged in as super user In this special case it is necessary to work as the root user because all the system files of the root file system need to be owned by the root 14 2 1Creating a New INITRD Image RAM disk image space is restricted The available space inside such a RAM disk image is defined when it is created To define
53. option can not be set root dev nfs ip 193 102 136 40 193 102 136 43 193 102 136 1 255 255 255 0 atc82 70 eth0 nfsroot nfsroot claugi atc8270 This is a configuration for root fs via NFS The whole IP configuration is done in the command line All of the above examples are described more in detail in the chapter 12 Root File System Strategies 11 1 3Compiling Kernel Generate a pure Linux kernel image for Kontron CPU gt make If lt architecture gt is defined as powerpc make can also generate a kernel image including the root filesystem in RAMES filesystem Enabling and usage of the RAMES is described later in this manual After a successful build process the generated file s can be found in arch powerpc boot arch powerpc boot vmlinux bin arch powerpc boot vmlinux gz Page 22 2007 Kontron Modular Computers ID 29331 Rev 07 For all other architectures to generate a Linux kernel image including an initial RAM disk invoke gt make zImage initrd For now only pure kernel images without the initial RAM disk should be created Creating and using the INITRD is described later in this manual The generated file has the following properties eit contains the Linux kernel in a compressed form eit contains code for unpacking and relocating the compressed kernel eit contains code detecting whether an INITRD image is present In this case the INITRD image is unpacked and mounted as root file system memory a
54. oss debugging To avoid confusion with the native x86 gdb this version s file name is powerpc linux gnu gdb gdbserver should be copied to the file system on the target machine and powerpc linux gnu gdb should be stored on the x86 host machine 18 3A Sample Debugging Session Before trying to start the debugging session the binary of an application suitable for debugging should be copied to the target file system To compile applications with debugging information included option g should be passed on to gcc compiler Applications built by Makefile provided in the BSP already have debugging information included For example the primes application is to be debugged At the terminal of target machine call usr x86host gt lt gdbserver path gt gdbserver aaa bbb ccc ddd 1234 lt primes app path gt primes Process lt primes app path gt primes created pid 148 where eaaa bbb ccc ddd is the IP address of the development host 01234 is the network port number on which the server will wait for a connection from the client this can be any available port number on the target On the development host gdb must be started and connected to the above gdbserver usr x86host gt powerpc linux gnu gdb GNU gdb 6 3 Copyright 2004 Free Software Foundation Inc GDB is free software covered by the GNU General Public License and you are welcome to change it and or distribute copies of it under certain condit
55. ot required to purchase an embedded Linux distribution for this target architecture in order to write applications 6Legend Throughout this manual the following typographical conventions and abbreviations for special elements are used Abbreviations Term Abbreviation The user name usr user prompt at the development host in directory dir usr x86host dir gt The root prompt root x86host dir The user prompt in the target system usr target The root prompt in the target system root target Special Fonts Term Example User entries or program outputs visible on a command root x86host home usr YaST shell Name of a file or directory lin bsp xxx Placeholder for a variable value lt version gt Placeholder for the system architecture will be ppc lt architecture gt arm x86 in the real world Page 6 2007 Kontron Modular Computers ID 29331 Rev 07 7System Requirements 7 1Development Host 7 1 1Hardware The following documentation assumes a development host which matches the following specifications eIntel Pentium III processor 800 MHz or higher eminimum RAM 128MB e500 MB available disk space enetwork connection via Ethernet 7 1 2Software A desktop Linux must be installed on the development host The installation should contain Linux development Network server components ftp telnet nfs and a serial terminal program e g minicom We recommend SuSE 9 0 or newer Know
56. packets 0 errors 0 dropped 0 overruns 0 frame 0 TX packets 0 errors 0 dropped 0 overruns 0 carrier 0 collisions 0 txqueuelen 0 RX bytes 0 0 0 b TX bytes 0 0 0 b jo Now the interface eth0 is configured and connection to the network should work This can be verified using e g ping tool ping 192 168 3 13 PING 192 168 3 13 192 168 3 13 56 data bytes 64 bytes from 192 168 3 13 icmp seq 0 ttl 64 time 5 2 ms 64 bytes from 192 168 3 13 icmp seq 1 ttl 64 time 0 3 ms 64 bytes from 192 168 3 13 icmp seq 2 ttl 64 time 0 4 ms 64 bytes from 192 168 3 13 icmp seq 3 ttl 64 time 0 3 ms 24 2ARM XScale Linux Kernel Linux kernel supports various processor architectures These architectures differ in the set of options presented to the user Therefore some of the kernel configuration menus may differ between kernel configured ex for PPC and ARM processors Also the details regarding kernel compilation process may differ in both cases 24 2 1Kernel compiling 1 The result of ARM XScale Linux kernel compilation is put in the lt arch gt arm boot directory 2 The kernel is always compiled to the z mage file 3 The ARM Linux kernel compiling is always performed by make without target parameters call in Kernel source directory The created z mage type only kernel kernel with initial ramdisk depends on the sources configuration 24 2 2Kernel Command Line The kernel command line for ARM architecture is configured in the menu
57. r Computers Page 57 Embedded Linux 2 6 User Manual 24Appendix C XScale IXP42x based eBrain specific considerations 24 1Using built in processor Ethernet Interfaces The E Brain family of Kontron embedded computers includes a few boards built on the Intel IXP42x processors XScale These are E Brain 425 and E Brain 420 The XScale embedded processors base on the ARM 5 processor core and they include a lot of additional functional blocks All network processors in the Intel IXP4XX product line have a unique distributed processing architecture that speeds development for a range of applications Each processor combines a high performance Intel XScale core with additional Network Processor Engines NPE to achieve wire speed packet processing performance The NPEs functional blocks require special software modules to operate This software is available on Intel Internet site to download Unfortunately the building of required software modules is not trivial It requires some additional activities to compile it against the 2 6 x Linux kernel versions 24 1 1 Downloading the software The required Intel software is available at http www intel com design network products npfamily ixp400_archives htm These are the required packages eIntel Hardware Access Software ver 2 0 IPL_ixp400AccessLibrary 2_0 zip eNPE microcode ver 2 0 IPL_ixp400NpeLibrary 2 0 5 zip Unfortunately the packages above are not suitable for Linux kernel 2 6 x bu
58. r the mount point and then mount this image to this mount point root x86host home usr bsp work ramdisk work mkdir mnttmp root x86host home usr bsp work ramdisk work mount o loop ramdisk image mnttmp Entering the mount directory and inspecting the contents will provide the following results root x86host home usr bsp work ramdisk work cd mnttmp root x86host home usr bsp work ramdisk work mnttmp ls o lost found root x86host home usr bsp work ramdisk work mnttmp And the diskfree command df will show the amount of available space in the ramdisk root x86host home usr bsp work ramdisk work mnttmp df h home usr bsp work ramdisk work ramdisk image 16M 13K 15M 1 home usr bsp work ramdisk work mnttmp Now the contents of the Linux GPL root file system can be unpacked to this directory root x86host home usr bsp work ramdisk work mnttmp tar preserve permissions xvjf opt linux26 bsp kom rootfs lt architecture gt lt subarchitecture gt lt version gt root filesystem lt architecture gt lt subarchitecture gt linux tar bz2 e g root x86host home usr bsp work ramdisk work mnttmp tar xvjf opt linux26 bsp kom rootfs ppc e300 0100 root filesystem ppc e300 linux tar bz2 Now this ramdisk image has to be unmounted and then compressed with gzip This is the format which is required to add it as an INITRD to the Kernel root x86host home usr bsp work ramdisk work mnttmp cd root x86host home
59. re detailed information can be found in the gdb documentation 18 4The gdbinit File At this point a gdbinit file should be created When gdb is started it automatically executes commands from its init files These files are named gdbinit on Linux systems During startup gdb does the following ereads the init file if any in the home directory eprocesses command line options and operands ereads the init file if any in the current working directory ereads command files specified by the x option In this case specific properties for the remote cross debugging needs to be configured It is recommended to create a gdbinit file in the directory from which gdb is called For example echo PowerPC remote debugging configured directory src set endian big endian target remote aaa bbb ccc eee 1234 set solib search path dev null set solib absolute prefix lt path to the target shared libraries gt lib With a gdbinit file in this format the connection to the remote target is automatically performed when gdb is called Now the start of the debug session as described in the previous chapter is performed as follows on the target command line usr target bin gdbserver aaa bbb ccc ddd 1234 bin primes Process lt primes application path gt primes created pid 148 Command on the development host command line usr x86host gt powerpc linux gnu gdb GNU gdb 6 3 Copyright 2004 Free Software Found
60. reby the following must be considered eavailable capacities esolid state or mechanical drive eremovable or fixed eform factor eaccess speed price eread only or read write Possible root file system strategeies are described in the following chapters 12 10nboard FLASH INITRD RAMFS The Kontron target CPUs have a minimum of 4 MB onboard flash which can be shared between the Linux kernel and a root file system in a ramdisk image gz format Kernel and INITRD RAMES are downloaded to the onboard flash in one step Advantages eno external storage media necessary eeasy download enon volatile Restrictions eread only espace restrictions kernel and file system must fit in the onboard flash eno remote debugging facilities For detailed information refer to 14 The Initial Ramdisk INITRD or 15 RAMES 12 2CompactFlash IBM Microdrive Many Kontron CPUs e g the Kontron CP620 PowerPC and all E Brain carriers have a CompactFlash IBM Microdrive compatible slot CompactFlash or IBM Microdrives are available in capacities between 32 MB and 1 GB Advantages ebroad range of memory capacities eadapters for the development host available easy download and software installation eremovable Restrictions erestricted lifetime Flash memories have a restricted lifetime if they are used for frequent write operations If the CompactFlash has an internal wear leveling algorithm the lifetime of this device will be
61. root x86host cd nfsroot root x86host nfsroot mkdir lt boardtype gt root x86host nfsroot cd lt boardtype gt root x86host nfsroot lt boardtype gt tar preserve permissions xvjf opt linux26 bsp kom rootfs lt architecture gt lt subarchitecture gt lt version gt root filesystem lt architecture gt lt subarchitecture gt linux tar bz2 13 4Booting from NFS Root File System After performing the above steps the target should be rebooted It will now be able to mount the root file system via NFS It should start into a Linux prompt with messages similar to the following IP Config Complete device eth2 addr 193 102 136 44 mask 255 255 255 0 gw 193 102 136 1 host ebrain8540 domain nis domain none bootserver 193 102 136 40 rootserver 193 102 136 40 rootpath Looking up port of RPC 100003 2 on 193 102 136 40 eth2 Full Duplex eth2 Speed 100BT eth2 Link is up Looking up port of RPC 100005 1 on 193 102 136 40 VFS Mounted root nfs filesystem Mounted devfs on dev Freeing unused kernel memory 96k init Please press Enter to activate this console BusyBox v1 00 2005 02 23 16 12 0000 Built in shell ash Enter help for a list of built in commands Processing etc profile Done ID 29331 Rev 07 2007 Kontron Modular Computers Page 29 Embedded Linux 2 6 User Manual 14The Initial Ramdisk INTRD 14 1Introduction INITRD provides the capability to load a small root file system t
62. t there is a solution to allow their proper compilation the SnapGear Embedded Linux patch The SnapGear patch for the Intel Access Library may be downloaded from http www snapgear org snapgear downloads html by using the link on this site named SnapGear IXP400 Access Library patch shar i This patch is valid only for Intel software version 2 0 The downloaded file should be esnapgear modules 20051115 sh Page 58 2007 Kontron Modular Computers ID 29331 Rev 07 24 1 2 Compiling the software modules In fact the SnapGear patch is intended to be used with SnapGear Embedded Linux But it is also possible to compile the software outside of the SnapGear distribution By doing this two additional files are required eautoconf h header file containing the configuration of Intel Hardware Access Library config containing configuration for build environment The compilation requires several steps 1 create the SnapGear build environment 2 uncompress Intel software 3 patch the Intel software with SnapGear patches 4 include the provided autoconf h and config files into build environment 5 configure the kernel sources for ARM XScale architecture 6 compile These steps look simple but a lot of mistakes may happen when performing them Therefore the Kontron BSP for E Brain 42x contains a proper structure and a script to build the software modules successfully In the installed BSP under directory 3rd_party_drivers the fol
63. t udev rules are stored in etc udev rules d udev rules This file should not be modified It contains default rules for all Linux systems The rules files are parsed in lexical order udev will stop processing rules as soon as it finds a matching rule in a rules file for the new item of hardware that has been detected Therefore it is important that own rules get processed before the udev defaults otherwise they will not take effect Details concerning udev configuration and operating may be found on udev project Internet site http www kernel org pub linux utils kernel hotplug udev htm The Linux GPL Root Filesystem starting from version 0103 uses the udev solution for device files handling It contains the common Linux udev rules as well as the rules specific for the Kontron E Brain boards The specific rules are put in the file etc udev rules d kontron rules Page 52 2007 Kontron Modular Computers ID 29331 Rev 07 20Additional Libraries in directory addl_libs The chapter 10 My First Linux Project mentioned that the script initproject sh creates a directory name addl_libs This additional library directory contains libraries which are derived from other open source projects e g pciutils and sysfsutils These libraries can be used within own applications if the following precautions are met eThe library versions match with the versions which are provided together with the Kontron GPL root file system If you are using a dif
64. the target boot the system as described in 12 6 ys required for booting ecreate a file system on the disk with a mkfs xxx program emount the drive eunpack the root file system which is provided in the BSP to the CompactFlash root target mount lt disk device gt mnt root target cd mnt root target tar preserve permissions xvjf path to rootfs package root filesystem lt arch gt lt subarch gt linux tar bz2 econfigure the kernel command line with reot dev lt disk device gt download this new kernel and reboot ID 29331 Rev 07 2007 Kontron Modular Computers Page 37 Embedded Linux 2 6 User Manual 17Root File System on an M Systems Disk On Chip 17 1General The Kontron PowerPC boards CP320 CP321 VMP1 and VMP2 are equipped with an onboard socket for the M Systems Disk On Chip This device is supported by the Memory Technology Device MTD support which is integrated within the Linux kernel The Linux MTD drivers are still subject to frequent modifications The official MTD site is http www linux mtd infradead org This chapter includes some excerpts from the excellent how to written by Vipin Malik vipin embeddedLinuxWorks com The original document can be found under ftp ftp uk linux org pub people dwmw2 mtd cvs mtd mtd jffs HOWTO txt For detailed information and useful links refer to the above document The Linux kernel source provided by Kontron already contains a version of the MT
65. tion For cross development the tool chain contains the Freescale provided libfsl_e500 a library This library replaces some of glibc math library calls providing code that executes much faster on with the e500 core especially double precision The library is included in the cross compilation tool chain for the e500 in a path that fits to the default library search path Page 48 2007 Kontron Modular Computers ID 29331 Rev 07 The following information is provided by Freescale regarding this library kkkxkxkkkxkkxkkkkxkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkxkxk Library Math e500 version 1 0 ESS3 Build 06 readme txt Copyright Motorola Inc 2004 Motorola Confidential Proprietary kkxkxkxkxkxkkkxkxkkkxkkkkkkkxkkkkkkkkkkkkkkxkkkkkkkkkkkkkkxkkkkkkkkkkxkxk 1 1 Contents libfsl_e500 a static ELF library for arithmetic and mathematical functions 1 2 Usage Example When using GNU tools add lfsl e500 to the command line before linking with the GNU libgcc or math libraries gcc CFLAGS L LDIR o myapp myapp c lfsl e500 lm 1 3 Functions supported 1 3 1 The following arithmetic functions are supported add __adddf3 sub __subdf3 multiply muldf3 divide _ divdf3 negate _ negdf2 less than l1tdf2 equal to eqdf2 greater than gtdf2 less or equal ledf2 not equal to nedf2 greater or equal gedf2 low level general comparison cmpdf2 low level unordered comparison __unor
66. type ex Block character pipe major number minor number Over the time there were different strategies to handle them Initially the device files were created statically during the system installation However there were some problems regarding this approach With the time the dev file had more and more files and only a small number of them were really used in the system However if the device used in the system wasn t popular or was some special device the proper device file had to be created specially Also the hot plugged devices caused lot of problems with static dev contents At some point the pseudo filesystem devfs has been developed and included in the Linux kernel The devfs controlled the device files creating during kernel boot up and drivers loading So the dev directory contained only the files of the initialized devices However this approach or solution was difficult to maintain in the kernel Therefore this mechanism has been removed from it The latest solution is udev This mechanism allows Linux users to have a dynamic dev directory and it provides the ability to have persistent device names It uses sysfs and sbin hotplug and runs entirely in userspace When populating dev udev decides which nodes to include and how to name them by reading a series of rule files included in etc udev rules d directory ID 29331 Rev 07 2007 Kontron Modular Computers Page 51 Embedded Linux 2 6 User Manual Defaul
67. v 07 Pinging the target from the development host is a way to check the correctness of the IP connection and parameters In addition a telnet connection from the development host to the target should now be possible The procedure how to download a kernel via FTP is described in detail later in this manual A user must be created on the development host that is allowed to login via ftp from the Kontron target For the following chapters it assumed that a user with the name targetuser and the password targetpasswd have been created The home directory of this user will be home targetuser To be able to store kernel images for the target all users should have write access to home targetuser usr x86host gt cd home usr x86host gt su Password root x86host chmod 777 targetuser root x86host ID 29331 Rev 07 2007 Kontron Modular Computers Page 13 Embedded Linux 2 6 User Manual 10 My First Linux Project 10 1 Project Initialisation If the BSP was installed using the RPM package recommended it is now installed somewhere under the opt directory chapter 8 1 2 BSP Package Installation All installed files are owned by root But for the daily development work it is highly recommended to work under a standard user account For this reason a local project directory has to be created inside the user s home area This is done by invoking the script initproject sh provided within the BSP installation
68. w start the program minicom if not already running gt minicom 9 1NetBootLoader Press the RESET button on the front panel The following prompt will appear NetBootLoader Kontron BootstrapLoader with Network support Press the Abort button type abort or login over telnet to cancel a running Boot Wait Time LED blinks Type help or to get online help This Product uses the Real Time Operating System ECOS from RedHat http www redhat com NetBtLd gt After a certain time typically 5 seconds the NetBootLoader will boot the installed operating system kernel if a valid start key of a kernel image is found in the onboard flash ID 29331 Rev 07 2007 Kontron Modular Computers Page 11 Embedded Linux 2 6 User Manual To cause the system to remain at the NetBootLoader command prompt enter NetBtLd gt abort Alternatively press the abort button on the front panel FDT Flattened Device Tree BSPs based on the powerpc architecture specification of the Linux kernel require a boot loader capable of passing a flattened device tree to the Linux kernel This is the case for all Kontron PowerPC BSPs designed for Kernel 2 6 17 or newer If a Linux kernel is designed for FDT is obvious by looking into the ARCH specification All Kernels which have ARCH powerpc are using FDT On the Kontron NetBootLoader use the command fdt 1 to switch on FDT support NetBtLd gt fdt 1 Enabling creation of flattened device
69. wing format ebsp lt boardtype gt kernelver lt index gt board support package containing tools libraries and sample applications efilesystem lt index gt Linux root file system etoolchain lt index gt gcc cross toolchain e kernelver lin drv lt boardtype gt lt index gt driver packages for peripharal boards contains own documentation which is not described in this manual Legend e kernelver optional version of the Linux kernel contained or supported e g 2 6 13 contains Kernel 2 6 13 elin26 supports Kernel 2 6 xx elin independent of a particular kernel version e lt index gt Kontron internal release number e g 0101 Page 8 2007 Kontron Modular Computers ID 29331 Rev 07 e lt boardtype gt board name e g eb8540 cp620 vmpl In addition to the Driver and BSP related directories there are the following directories on the CDROM edoc This directory contains additional documentation e g notes on particular distributions eGPLSOURCES This directory contains sources of packages which are contained in the BSP s or drivers in binary format The contents of GPLSOURCES are not required for Linux development as described in this manual These sources are provided under the GPL without any warranty or support 8 1 2BSP Package Installation Three packages from the Kontron CD ROM must be installed on the development host ethe BSP component bsp lt boardtype gt lt kernelver gt lt index gt ethe
70. x kernel 2 6 x adapted to work with the particular target hardware The Linux kernel is free software covered by the GNU General Public License The kernel provided by the Kontron embedded Linux has some extensions to the standard kernel to support the specific hardware features of the Kontron boards However all these modifications to the vanilla kernel are done in a way which conforms to the open source conventions of the Linux kernel and all of these modifications will be made available to the open source community a Set environment for cross development Please dont forget to source the environment sh script as mentioned above bspwork sample project gt source scripts environment sh Setting KOMKERNELDIR to home lt username gt bspwork sample project linux Setting KOMINSTALLDIR to home lt username gt bspwork sample project boot Kernel Version lt kernel version gt b Load default configuration for the board The Linux kernel provides a default configuration for each Kontron board supported All default configurations can be found under the directory arch lt architecture gt configs The filename is typically lt boardtype gt _defconfig To load a default configuration enter usr x86host bspwork sample project linux gt make lt boardtype gt defconfig example usr x86host bspwork linux gt make eb8540 defconfig ID 29331 Rev 07 2007 Kontron Modular Computers Page 15 Embedded Linux 2 6 User Manual
71. xt2 minix For this reason also file system support for the chosen type must be enabled in the kernel statically 14 3 2Kernel Command Line In the kernel command line the root device must be configured as root dev ramO 14 3 3Building a Kernel image including INITRD To create a kernel image including this image as an INITRD just call usr x86host bsp work linux gt make zImage initrd This will generate a file z mage initrd kom in the subdirectory arch lt architecture gt boot images For XScale based boards please refer to Appendix C XScale IXP42x based eBrain specific considerations 14 4Downloading Download the newly created kernel image as described in chapter 11 2 Network Download ID 29331 Rev 07 2007 Kontron Modular Computers Page 33 Embedded Linux 2 6 User Manual 14 5Booting Connect the minicom terminal and boot the system by pressing the reset button The early kernel startup messages now contain a line initrd at which was not present when the kernel was booted without an initrd e g run loaded at 00000100 00261298 relocated to 00800000 00A61198 board data at OOAS5FO2C OOASFO98 relocated to 008052D8 00805344 zimage at OO805AD1 00920EFE initrd at 00921000 OOA5E81C avail ram 00A62000 10000000 Linux PPC load root dev ram0O console ttyS0O 9600 ip 193 102 136 44 193 102 136 43 193 102 136 1 255 255 255 0 eb8540 initrd et h2 off Uncompressing Linux done Now booting the

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