kgdb quick start

Contents Hardware setup Software setup Compiling the kernel on the development machine Starting the debug session Using KGDB over ethernet interface Useful links and miscellaneous information Hardware setup Use a Null modem serial cable to connect across the Target and Development machines . [ Development machine ]----------------------------------[ Target machine ] 1-Hardware pinout for the null modem serial cable  OR    2-Hardware pinout for the null modem serial cable Testing  the working of the Null-modem serial cable.  On the Development machine :  stty ispeed 115200 ospeed 115200 -F /dev/ttyS0 cat testfile.txt > /dev/ttyS0 On the Target machine : stty ispeed 115200 ospeed 115200 -F /dev/ttyS0 cat /dev/ttyS0 The following settings are used for the Remote debugging session, automatically. <root #> stty -F /dev/ttyS0 speed 115200 baud; line = 0; min = 1; time = 0; -brkint -icrnl -imaxbel -opost -onlcr -isig -icanon -iexten -echo -echoe -echok -echoctl -echoke Top  Software setup Download Linux kernel source : linux-2.6.15.5.tar.bz2 Download the Kgdb patch : linux-2.6.15.5-kgdb-2.4.tar.bz2 Unzip the kernel sources     cd ${BASE_DIR}     tar -jxvf linux-2.6.15.5.tar.bz2 Unzip the kgdb patch     tar -jxvf linux-2.6.15.5-kgdb-2.4.tar.bz2 Change the directory as follows:     cd ${BASE_DIR}/linux-2.6.15.5 Apply KGDB patches     patch -p1 < ${BASE_DIR}/linux-2.6.15.5-kgdb-2.4/core-lite.patch     ........     patch -p1 < ${BASE_DIR}/linux-2.6.15.5-kgdb-2.4/i386.patch Follow the order mentioned in "series" file while applying the patches Top  Compiling the kernel on the development machine In the ${BASE_DIR}/linux-2.6.15.5/Makefile, set the EXTRAVERSION = -kgdb make xconfig/oldconfig/menuconfig     Select the options appropriate for the target machine Hardware.     Select the options pertaining to kgdb under "Kernel hacking" as shown here make bzImage Transfer the built kernel to the Target machine from the Development machine. Copy the Kernel image from ${BASE_DIR}/linux-2.6.15.5/arch/i386/boot/bzImage to the target machine as /boot/vmlinuz-2.6.15.5-kgdb Copy the Map file from ${BASE_DIR}/linux-2.6.15.5/System.map to the target machine as /boot/System.map-2.6.15.5-kgdb Also create links as follows:     ln -s /boot/vmlinuz-2.6.15.5-kgdb /boot/vmlinuz     ln -s /boot/System.map-2.6.15.5-kgdb /boot/System.map Edit the /boot/grub/grub.conf file in the target machine to have the kgdb enabled kernel entry.     title Linux-2.6.15.5-kgdb     root (hd0,0)     kernel /boot/vmlinuz-2.6.15.5-kgdb ro root=/dev/hda1 kgdbwait kgdb8250=0,115200 Top  Starting the debug session After booting, the target machine will wait for the host development machine to connect, by displaying the message :-     Waiting for connection from remote gdb... cd ${BASE_DIR}/linux-2.6.15.5 For starting a debug session with baud rate of 115200 on /dev/ttyS0 , run the following as "root" user:-     <root#> gdb ./vmlinux     GNU gdb (GDB) 7.1-ubuntu     Copyright (C) 2010 Free Software Foundation, Inc.     License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>     This is free software: you are free to change and redistribute it.     There is NO WARRANTY, to the extent permitted by law. Type "show copying"     and "show warranty" for details.     This GDB was configured as "i486-linux-gnu".     For bug reporting instructions, please see:     <http://www.gnu.org/software/gdb/bugs/>...     (gdb) set remotebaud 115200     (gdb) target remote /dev/ttyS0     Remote debugging using /dev/ttyS0     breakpoint () at kernel/kgdb.c:1212     1212 atomic_set(&kgdb_setting_breakpoint, 0);     (gdb) For further commands refer http://kgdb.geeksofpune.in/tockdebug.htm Top  Using KGDB over ethernet interface Add the following kernel parameter to the grub entry:     kgdboe=@10.0.0.6/,@10.0.0.3/ (that's kgdboe=@LOCAL-IP/,@REMOTE-IP/) # Sample grub.cfg which will by default boot the kgdb enabled kernel     title Linux-2.6.15.5-kgdb(eth)     root (hd0,0)     kernel /boot/vmlinuz-2.6.15.5-kgdb ro root=/dev/hda1 kgdboe=@10.0.0.6/,@10.0.0.3/ console=ttyS0,115200 For starting a debug session, type the following:     (gdb) ./vmlinux     (gdb) target remote udp:HOSTNAME:6443 For further commands refer http://kgdb.geeksofpune.in/tockdebug.htm Top  Useful links and Miscellaneous information Useful Links :  http://kgdb.sourceforge.net/ http://kgdb.geeksofpune.in/ http://kgdb.geeksofpune.in/downloads/ Active Developers :       Amit Kale (amitkale@geeksofpune.in),       Swapnil Pimpale (swapnil@geeksofpune.in) Bug Report: kgdb-bugreport@lists.sourceforge.net

Contents Hardware setup Software setup Compiling the kernel on the development machine Starting the debug session Using KGDB over ethernet interface Useful links and miscellaneous information Hardware setup Use a Null modem serial cable to connect across the Target and Development machines . [ Development machine ]----------------------------------[ Target machine ] 1-Hardware pinout for the null modem serial cable  OR    2-Hardware pinout for the null modem serial cable Testing  the working of the Null-modem serial cable.  On the Development machine :  stty ispeed 115200 ospeed 115200 -F /dev/ttyS0 cat testfile.txt > /dev/ttyS0 On the Target machine : stty ispeed 115200 ospeed 115200 -F /dev/ttyS0 cat /dev/ttyS0 The following settings are used for the Remote debugging session, automatically. <root #> stty -F /dev/ttyS0 speed 115200 baud; line = 0; min = 1; time = 0; -brkint -icrnl -imaxbel -opost -onlcr -isig -icanon -iexten -echo -echoe -echok -echoctl -echoke Top  Software setup Download Linux kernel source : linux-2.6.15.5.tar.bz2 Download the Kgdb patch : linux-2.6.15.5-kgdb-2.4.tar.bz2 Unzip the kernel sources     cd ${BASE_DIR}     tar -jxvf linux-2.6.15.5.tar.bz2 Unzip the kgdb patch     tar -jxvf linux-2.6.15.5-kgdb-2.4.tar.bz2 Change the directory as follows:     cd ${BASE_DIR}/linux-2.6.15.5 Apply KGDB patches     patch -p1 < ${BASE_DIR}/linux-2.6.15.5-kgdb-2.4/core-lite.patch     ........     patch -p1 < ${BASE_DIR}/linux-2.6.15.5-kgdb-2.4/i386.patch Follow the order mentioned in "series" file while applying the patches Top  Compiling the kernel on the development machine In the ${BASE_DIR}/linux-2.6.15.5/Makefile, set the EXTRAVERSION = -kgdb make xconfig/oldconfig/menuconfig     Select the options appropriate for the target machine Hardware.     Select the options pertaining to kgdb under "Kernel hacking" as shown here make bzImage Transfer the built kernel to the Target machine from the Development machine. Copy the Kernel image from ${BASE_DIR}/linux-2.6.15.5/arch/i386/boot/bzImage to the target machine as /boot/vmlinuz-2.6.15.5-kgdb Copy the Map file from ${BASE_DIR}/linux-2.6.15.5/System.map to the target machine as /boot/System.map-2.6.15.5-kgdb Also create links as follows:     ln -s /boot/vmlinuz-2.6.15.5-kgdb /boot/vmlinuz     ln -s /boot/System.map-2.6.15.5-kgdb /boot/System.map Edit the /boot/grub/grub.conf file in the target machine to have the kgdb enabled kernel entry.     title Linux-2.6.15.5-kgdb     root (hd0,0)     kernel /boot/vmlinuz-2.6.15.5-kgdb ro root=/dev/hda1 kgdbwait kgdb8250=0,115200 Top  Starting the debug session After booting, the target machine will wait for the host development machine to connect, by displaying the message :-     Waiting for connection from remote gdb... cd ${BASE_DIR}/linux-2.6.15.5 For starting a debug session with baud rate of 115200 on /dev/ttyS0 , run the following as "root" user:-     <root#> gdb ./vmlinux     GNU gdb (GDB) 7.1-ubuntu     Copyright (C) 2010 Free Software Foundation, Inc.     License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>     This is free software: you are free to change and redistribute it.     There is NO WARRANTY, to the extent permitted by law. Type "show copying"     and "show warranty" for details.     This GDB was configured as "i486-linux-gnu".     For bug reporting instructions, please see:     <http://www.gnu.org/software/gdb/bugs/>...     (gdb) set remotebaud 115200     (gdb) target remote /dev/ttyS0     Remote debugging using /dev/ttyS0     breakpoint () at kernel/kgdb.c:1212     1212 atomic_set(&kgdb_setting_breakpoint, 0);     (gdb) For further commands refer http://kgdb.geeksofpune.in/tockdebug.htm Top  Using KGDB over ethernet interface Add the following kernel parameter to the grub entry:     kgdboe=@10.0.0.6/,@10.0.0.3/ (that's kgdboe=@LOCAL-IP/,@REMOTE-IP/) # Sample grub.cfg which will by default boot the kgdb enabled kernel     title Linux-2.6.15.5-kgdb(eth)     root (hd0,0)     kernel /boot/vmlinuz-2.6.15.5-kgdb ro root=/dev/hda1 kgdboe=@10.0.0.6/,@10.0.0.3/ console=ttyS0,115200 For starting a debug session, type the following:     (gdb) ./vmlinux     (gdb) target remote udp:HOSTNAME:6443 For further commands refer http://kgdb.geeksofpune.in/tockdebug.htm Top  Useful links and Miscellaneous information Useful Links :  http://kgdb.sourceforge.net/ http://kgdb.geeksofpune.in/ http://kgdb.geeksofpune.in/downloads/ Active Developers :       Amit Kale (amitkale@geeksofpune.in),       Swapnil Pimpale (swapnil@geeksofpune.in) Bug Report: kgdb-bugreport@lists.sourceforge.net Using kgdb, kdb and the kernel debugger internals  by  <jason.wessel@windriver.com> : https://www.kernel.org/doc/htmldocs/kgdb/index.html