How To Cross Compile GDB and Run in Embedded System

How To Cross Compile GDB and Run in Embedded System

by cawan (cawan[at]ieee.org or chuiyewleong[at]hotmail.com)

on 21/11/2012

GDB is a useful tool to debug applications running in linux system. For the case of
embedded linux system, it is important have a version of GDB that can run in proper
in the embedded environment. As oppose to x86 environment which is mostly being used
in PC platform, embedded system adopts a large variety of RISC architecture to run
the system. There are ARM, MIPS, PPC... and each of them might run in little or big
endian mode. So, it is a little bit hard to have a generic version of GDB that can
run in all embedded platforms. Therefore, it is crucial to harness the power of cross
compilation in all the ways in order to make use of those useful tools such as GDB in
embedded environment. Regarding to the fundamental knowledge of cross compilation,
please refer my previous paper in this blog, "What is Cross Compilation ? Cross
Compilation Demystified For Embedded Linux System". So, let us start to cross compile
the GDB for our embedded platform right now. The embedded platform that we are going
to use is MIPS 24k, little-endian mode, 500MHz, with 256MB DDR2 RAM.

Host:# ./configure --help
`configure' configures this package to adapt to many kinds of systems.

Usage: ./configure [OPTION]... [VAR=VALUE]...

To assign environment variables (e.g., CC, CFLAGS...), specify them as
VAR=VALUE.  See below for descriptions of some of the useful variables.

Defaults for the options are specified in brackets.

Configuration:
  -h, --help              display this help and exit
      --help=short        display options specific to this package
      --help=recursive    display the short help of all the included packages
  -V, --version           display version information and exit
  -q, --quiet, --silent   do not print `checking...' messages
      --cache-file=FILE   cache test results in FILE [disabled]
  -C, --config-cache      alias for `--cache-file=config.cache'
  -n, --no-create         do not create output files
      --srcdir=DIR        find the sources in DIR [configure dir or `..']

Installation directories:
  --prefix=PREFIX         install architecture-independent files in PREFIX
                          [/usr/local]
  --exec-prefix=EPREFIX   install architecture-dependent files in EPREFIX
                          [PREFIX]

By default, `make install' will install all the files in
`/usr/local/bin', `/usr/local/lib' etc.  You can specify
an installation prefix other than `/usr/local' using `--prefix',
for instance `--prefix=$HOME'.

For better control, use the options below.

Fine tuning of the installation directories:
  --bindir=DIR            user executables [EPREFIX/bin]
  --sbindir=DIR           system admin executables [EPREFIX/sbin]
  --libexecdir=DIR        program executables [EPREFIX/libexec]
  --sysconfdir=DIR        read-only single-machine data [PREFIX/etc]
  --sharedstatedir=DIR    modifiable architecture-independent data [PREFIX/com]
  --localstatedir=DIR     modifiable single-machine data [PREFIX/var]
  --libdir=DIR            object code libraries [EPREFIX/lib]
  --includedir=DIR        C header files [PREFIX/include]
  --oldincludedir=DIR     C header files for non-gcc [/usr/include]
  --datarootdir=DIR       read-only arch.-independent data root [PREFIX/share]
  --datadir=DIR           read-only architecture-independent data [DATAROOTDIR]
  --infodir=DIR           info documentation [DATAROOTDIR/info]
  --localedir=DIR         locale-dependent data [DATAROOTDIR/locale]
  --mandir=DIR            man documentation [DATAROOTDIR/man]
  --docdir=DIR            documentation root [DATAROOTDIR/doc/PACKAGE]
  --htmldir=DIR           html documentation [DOCDIR]
  --dvidir=DIR            dvi documentation [DOCDIR]
  --pdfdir=DIR            pdf documentation [DOCDIR]
  --psdir=DIR             ps documentation [DOCDIR]

Program names:
  --program-prefix=PREFIX            prepend PREFIX to installed program names
  --program-suffix=SUFFIX            append SUFFIX to installed program names
  --program-transform-name=PROGRAM   run sed PROGRAM on installed program names

System types:
  --build=BUILD     configure for building on BUILD [guessed]
  --host=HOST       cross-compile to build programs to run on HOST [BUILD]
  --target=TARGET   configure for building compilers for TARGET [HOST]

Optional Features:
  --disable-option-checking  ignore unrecognized --enable/--with options
  --disable-FEATURE       do not include FEATURE (same as --enable-FEATURE=no)
  --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]
  --enable-gold           use gold instead of ld
  --enable-libada         build libada directory
  --enable-libssp         build libssp directory
  --enable-build-with-cxx build with C++ compiler instead of C compiler
  --disable-ppl-version-check    disable check for PPL version
  --disable-cloog-version-check  disable check for CLooG version
  --enable-lto            enable link time optimization support
  --enable-stage1-languages[=all]   choose additional languages to build during
                          stage1.  Mostly useful for compiler development.
  --enable-objc-gc        enable use of Boehm's garbage collector with the
                          GNU Objective-C runtime
  --enable-bootstrap      enable bootstrapping [yes if native build]
  --enable-serial-[{host,target,build}-]configure
                          force sequential configuration of
                          sub-packages for the host, target or build
                          machine, or all sub-packages
  --enable-maintainer-mode enable make rules and dependencies not useful
                          (and sometimes confusing) to the casual installer
  --enable-stage1-checking[=all]   choose additional checking for stage1
                          of the compiler
  --enable-werror         enable -Werror in bootstrap stage2 and later

Optional Packages:
  --with-PACKAGE[=ARG]    use PACKAGE [ARG=yes]
  --without-PACKAGE       do not use PACKAGE (same as --with-PACKAGE=no)
  --with-build-libsubdir=DIR  Directory where to find libraries for build system
  --with-mpc=PATH        specify prefix directory for installed MPC package.
                          Equivalent to --with-mpc-include=PATH/include
                          plus --with-mpc-lib=PATH/lib
  --with-mpc-include=PATH
                          specify directory for installed MPC include files
  --with-mpc-lib=PATH    specify directory for the installed MPC library
  --with-mpfr-dir=PATH    this option has been REMOVED
  --with-mpfr=PATH        specify prefix directory for installed MPFR package.
                          Equivalent to --with-mpfr-include=PATH/include
                          plus --with-mpfr-lib=PATH/lib
  --with-mpfr-include=PATH
                          specify directory for installed MPFR include files
  --with-mpfr-lib=PATH    specify directory for the installed MPFR library
  --with-gmp-dir=PATH     this option has been REMOVED
  --with-gmp=PATH         specify prefix directory for the installed GMP package.
                          Equivalent to --with-gmp-include=PATH/include
                          plus --with-gmp-lib=PATH/lib
  --with-gmp-include=PATH specify directory for installed GMP include files
  --with-gmp-lib=PATH     specify directory for the installed GMP library
  --with-host-libstdcxx=L Use linker arguments L to link with libstdc++
                          when linking with PPL
  --with-stage1-ldflags=FLAGS Linker flags for stage1
  -with-stage1-libs=LIBS      Libraries for stage1
  --with-boot-libs=LIBS     Libraries for stage2 and later
  --with-boot-ldflags=FLAGS Linker flags for stage2 and later
  --with-ppl=PATH         Specify prefix directory for the installed PPL package
                          Equivalent to --with-ppl-include=PATH/include
                          plus --with-ppl-lib=PATH/lib
  --with-ppl-include=PATH Specify directory for installed PPL include files
  --with-ppl-lib=PATH     Specify the directory for the installed PPL library
  --with-cloog=PATH       Specify prefix directory for the installed CLooG-PPL package
                          Equivalent to --with-cloog-include=PATH/include
                          plus --with-cloog-lib=PATH/lib
  --with-cloog-include=PATH Specify directory for installed CLooG include files
  --with-cloog-lib=PATH   Specify the directory for the installed CLooG library
  --with-libelf=PATH       Specify prefix directory for the installed libelf package
                          Equivalent to --with-libelf-include=PATH/include
                          plus --with-libelf-lib=PATH/lib
  --with-libelf-include=PATH Specify directory for installed libelf include files
  --with-libelf-lib=PATH   Specify the directory for the installed libelf library
  --with-build-sysroot=SYSROOT
                          use sysroot as the system root during the build
  --with-debug-prefix-map='A=B C=D ...'
                             map A to B, C to D ... in debug information
--with-build-config='NAME NAME2...'
                          Use config/NAME.mk build configuration
  --with-build-time-tools=PATH
                          use given path to find target tools during the build

Some influential environment variables:
  CC          C compiler command
  CFLAGS      C compiler flags
  LDFLAGS     linker flags, e.g. -L if you have libraries in a
              nonstandard directory
  LIBS        libraries to pass to the linker, e.g. -l
  CPPFLAGS    C/C++/Objective C preprocessor flags, e.g. -I if
              you have headers in a nonstandard directory
  CXX         C++ compiler command
  CXXFLAGS    C++ compiler flags
  CPP         C preprocessor
  AR          AR for the host
  AS          AS for the host
  DLLTOOL     DLLTOOL for the host
  LD          LD for the host
  LIPO        LIPO for the host
  NM          NM for the host
  RANLIB      RANLIB for the host
  STRIP       STRIP for the host
  WINDRES     WINDRES for the host
  WINDMC      WINDMC for the host
  OBJCOPY     OBJCOPY for the host
  OBJDUMP     OBJDUMP for the host
  CC_FOR_TARGET
              CC for the target
  CXX_FOR_TARGET
              CXX for the target
  GCC_FOR_TARGET
              GCC for the target
  GCJ_FOR_TARGET
              GCJ for the target
  GFORTRAN_FOR_TARGET
              GFORTRAN for the target
  AR_FOR_TARGET
              AR for the target
  AS_FOR_TARGET
              AS for the target
  DLLTOOL_FOR_TARGET
              DLLTOOL for the target
  LD_FOR_TARGET
              LD for the target
  LIPO_FOR_TARGET
              LIPO for the target
  NM_FOR_TARGET
              NM for the target
  OBJDUMP_FOR_TARGET
              OBJDUMP for the target
  RANLIB_FOR_TARGET
              RANLIB for the target
  STRIP_FOR_TARGET
              STRIP for the target
  WINDRES_FOR_TARGET
              WINDRES for the target
  WINDMC_FOR_TARGET
              WINDMC for the target

Use these variables to override the choices made by `configure' or to help
it to find libraries and programs with nonstandard names/locations.

Report bugs to the package provider.
Host:#

Well, let's define --host, --target, and CC for our first try of GDB cross
compilation.

Host:# ./configure --host=mips-linux-gnu --target=mips-linux-gnu CC="mips-linux-gnu-gcc -EL"

Host:# make

After a while, we get the following error.

configure: WARNING: no enhanced curses library found; disabling TUI
checking for library containing tgetent... no
configure: error: no termcap library found
make[1]: *** [configure-gdb] Error 1
make[1]: Leaving directory `/home/smp383/mips-4.3/bin/gdb-7.1'
make: *** [all] Error 2

No termcap library found... It seems GDB needs termcap library to complete the
cross compilation. So, we need to cross compile a termcap library first.

Host:# wget http://gnuwin32.sourceforge.net/downlinks/termcap-src-zip.php

Host:# ls *.zip
termcap-1.3.1-src.zip
Host:# mkdir libtermcap
Host:# cp termcap-1.3.1-src.zip ./libtermcap/
Host:# cd libtermcap/
Host:# ls
termcap-1.3.1-src.zip
Host:# unzip termcap-1.3.1-src.zip
Archive:  termcap-1.3.1-src.zip
TermCap 1.3.1: sources
TermCap: terminal-capability library
  inflating: src/COPYING            
  inflating: src/ChangeLog          
  inflating: src/INSTALL            
  inflating: src/Makefile           
  inflating: src/Makefile.in        
  inflating: src/NEWS               
  inflating: src/README             
  inflating: src/config.cache       
  inflating: src/config.log         
  inflating: src/config.status      
  inflating: src/configure          
  inflating: src/configure.in       
  inflating: src/configure_help.txt 
  inflating: src/install-sh         
  inflating: src/makefile.mingw     
  inflating: src/mkinstalldirs      
  inflating: src/termcap.c          
  inflating: src/termcap.h          
  inflating: src/termcap.info       
  inflating: src/termcap.info-1     
  inflating: src/termcap.info-2     
  inflating: src/termcap.info-3     
  inflating: src/termcap.info-4     
  inflating: src/termcap.src        
  inflating: src/termcap.texi       
  inflating: src/texinfo.te_        
  inflating: src/tparam.c           
  inflating: src/version.c          
  inflating: manifest/termcap-1.3.1-src.ver 
  inflating: manifest/termcap-1.3.1-src.mft 
Host:# ls
manifest  src  termcap-1.3.1-src.zip
Host:# cd src
Host:# ls
ChangeLog           configure.in  makefile.mingw  termcap.info    termcap.texi
config.cache        COPYING       mkinstalldirs   termcap.info-1  texinfo.te_
config.log          INSTALL       NEWS            termcap.info-2  tparam.c
config.status       install-sh    README          termcap.info-3  version.c
configure           Makefile      termcap.c       termcap.info-4
configure_help.txt  Makefile.in   termcap.h       termcap.src
Host:# ./configure --help
bash: ./configure: Permission denied
Host:# ls -l ./configure
-rw-r--r-- 1 root root 30285 1995-07-27 03:52 ./configure
Host:# chmod 755 ./configure
Host:# ls -l ./configure
-rwxr-xr-x 1 root root 30285 1995-07-27 03:52 ./configure
Host:# ./configure --help
Usage: configure [options] [host]
Options: [defaults in brackets after descriptions]
Configuration:
  --cache-file=FILE       cache test results in FILE
  --help                  print this message
  --no-create             do not create output files
  --quiet, --silent       do not print `checking...' messages
  --version               print the version of autoconf that created configure
Directory and file names:
  --prefix=PREFIX         install architecture-independent files in PREFIX
                          [/usr/local]
  --exec-prefix=PREFIX    install architecture-dependent files in PREFIX
                          [same as prefix]
  --srcdir=DIR            find the sources in DIR [configure dir or ..]
  --program-prefix=PREFIX prepend PREFIX to installed program names
  --program-suffix=SUFFIX append SUFFIX to installed program names
  --program-transform-name=PROGRAM run sed PROGRAM on installed program names
Host type:
  --build=BUILD           configure for building on BUILD [BUILD=HOST]
  --host=HOST             configure for HOST [guessed]
  --target=TARGET         configure for TARGET [TARGET=HOST]
Features and packages:
  --disable-FEATURE       do not include FEATURE (same as --enable-FEATURE=no)
  --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]
  --with-PACKAGE[=ARG]    use PACKAGE [ARG=yes]
  --without-PACKAGE       do not use PACKAGE (same as --with-PACKAGE=no)
  --x-includes=DIR        X include files are in DIR
  --x-libraries=DIR       X library files are in DIR
--enable and --with options recognized:
  --enable-install-termcap install the termcap data file
  --with-termcap=FILE     use data file FILE instead of /etc/termcap
Host:# ./configure --host=mips-linux-gnu --target=mips-linux-gnu CC="mips-linux-gnu-gcc -EL"
configure: warning: CC=mips-linux-gnu-gcc -EL: invalid host type
loading cache ./config.cache
checking for gcc... (cached) gcc
checking whether we are using GNU C... (cached) yes
checking for ranlib... (cached) ranlib
checking for a BSD compatible install... /usr/bin/install -c
checking how to run the C preprocessor... (cached) gcc -E
checking for string.h... (cached) no
checking for unistd.h... (cached) no
checking whether cross-compiling... (cached) no
checking for ANSI C header files... (cached) yes
updating cache ./config.cache
creating ./config.status
creating Makefile
Host:# make
gcc -c  -DTERMCAP_FILE=\"/etc/termcap\" -I. -I. -g termcap.c
termcap.c:44: warning: conflicting types for built-in function ‘malloc’
termcap.c:45: warning: conflicting types for built-in function ‘realloc’
termcap.c: In function ‘memory_out’:
termcap.c:96: warning: incompatible implicit declaration of built-in function ‘exit’
termcap.c: In function ‘tgetent’:
termcap.c:511: warning: incompatible implicit declaration of built-in function ‘strcpy’
termcap.c:541: warning: incompatible implicit declaration of built-in function ‘strlen’
termcap.c:549: warning: incompatible implicit declaration of built-in function ‘strcpy’
termcap.c:550: warning: incompatible implicit declaration of built-in function ‘strlen’
termcap.c:559: warning: incompatible implicit declaration of built-in function ‘free’
termcap.c:567: warning: incompatible implicit declaration of built-in function ‘free’
termcap.c:597: warning: incompatible implicit declaration of built-in function ‘free’
termcap.c: In function ‘gobble_line’:
termcap.c:747: warning: incompatible implicit declaration of built-in function ‘bcopy’
gcc -c  -DTERMCAP_FILE=\"/etc/termcap\" -I. -I. -g tparam.c
tparam.c:32: warning: conflicting types for built-in function ‘malloc’
tparam.c:33: warning: conflicting types for built-in function ‘realloc’
tparam.c: In function ‘memory_out’:
tparam.c:52: warning: incompatible implicit declaration of built-in function ‘exit’
tparam.c: In function ‘tparam1’:
tparam.c:161: warning: incompatible implicit declaration of built-in function ‘bcopy’
tparam.c:222: warning: incompatible implicit declaration of built-in function ‘strlen’
tparam.c:300: warning: incompatible implicit declaration of built-in function ‘abort’
tparam.c:310: warning: incompatible implicit declaration of built-in function ‘strcat’
gcc -c  -DTERMCAP_FILE=\"/etc/termcap\" -I. -I. -g version.c
ar rc libtermcap.a termcap.o tparam.o version.o
ranlib libtermcap.a

Well, the libtermcap.a is generated, but based on the output message, the binary
is suspicious to be MIPS compatible. Let's check.

Host:# ls *.o
termcap.o  tparam.o  version.o
Host:# file termcap.o
termcap.o: ELF 32-bit LSB relocatable, Intel 80386, version 1 (SYSV), not stripped

Yes, our suspicion is correct, the binary is in x86 format. Let us define the CC flag
in explicit way under the make process.

Host:# make distclean
rm -f *.a *.o core
rm -f Makefile config.status config.cache config.log
Host:# ./configure --host=mips-linux-gnu --target=mips-linux-gnu CC="mips-linux-gnu-gcc -EL"
configure: warning: CC=mips-linux-gnu-gcc -EL: invalid host type
creating cache ./config.cache
checking for gcc... gcc
checking whether we are using GNU C... yes
checking whether gcc accepts -g... yes
checking for ranlib... ranlib
checking for a BSD compatible install... /usr/bin/install -c
checking how to run the C preprocessor... gcc -E
checking for string.h... yes
checking for unistd.h... yes
checking whether cross-compiling... no
checking for ANSI C header files... yes
updating cache ./config.cache
creating ./config.status
creating Makefile
Host:# make CC="mips-linux-gnu-gcc -EL"
mips-linux-gnu-gcc -EL -c  -DHAVE_STRING_H=1 -DHAVE_UNISTD_H=1 -DSTDC_HEADERS=1 
-DTERMCAP_FILE=\"/etc/termcap\" -I. -I. -g termcap.c
mips-linux-gnu-gcc -EL -c  -DHAVE_STRING_H=1 -DHAVE_UNISTD_H=1 -DSTDC_HEADERS=1 
-DTERMCAP_FILE=\"/etc/termcap\" -I. -I. -g tparam.c
mips-linux-gnu-gcc -EL -c  -DHAVE_STRING_H=1 -DHAVE_UNISTD_H=1 -DSTDC_HEADERS=1 
-DTERMCAP_FILE=\"/etc/termcap\" -I. -I. -g version.c
ar rc libtermcap.a termcap.o tparam.o version.o
ranlib libtermcap.a
Host:# file termcap.o
termcap.o: ELF 32-bit LSB relocatable, MIPS, MIPS32 rel2 version 1 (SYSV), not stripped
Host:#

Well, we got our libtermcap.a now. Let us back to the cross compilation process of
GDB. In order to let the cross compiler can locate the exact location of our termcap
library, let us define it in explicit way.

Host:# make distclean

Host:# ./configure --host=mips-linux-gnu --target=mips-linux-gnu CC="mips-linux-gnu-gcc -EL"
--with-libtermcap="$PWD"

Host:# make

However, after a while, we still get the same error. It seems the explicit definition
of termcap library didn't work properly. Let's us get to the respective configuration
file and do the explicit definition of termcap library again.

Host:# find . -type f -name "configure" -exec grep -il "no termcap library found" {} \;
./gdb/configure
Host:# cd gdb
Host:# ./configure --host=mips-linux-gnu --target=mips-linux-gnu CC="mips-linux-gnu-gcc -EL"
--with-libtermcap="/home/smp383/mips-4.3/bin/gdb-7.1"

Unfortunately, the error still there... It seems the problem can't be solved in graceful
way. So, we should consider to modify the configuration file directly. Let's start now.

Host:# nano configure

Well, the string "no termcap library found" is at line 8714. After some reading on
that portion of codes, it seems the variable "ac_cv_search_tgetent" needs to be
defined. At line 8644, it is defined as "../libtermcap/libtermcap.a". But, it seems
line 8644 will not getting executed in the case statement. Hence, we should hard
define it at the outer section of the case statement. So, let us put a new line of
"ac_cv_search_tgetent="../libtermcap.a" at line 8638. Therefore, from line 8635 to
line 8645 of the configuration file should look something similar to this.

# Since GDB uses Readline, we need termcap functionality.  In many
# cases this will be provided by the curses library, but some systems
# have a seperate termcap library, or no curses library at all.
ac_cv_search_tgetent="../libtermcap.a"

case $host_os in
  cygwin*)
    if test -d $srcdir/libtermcap; then
      LIBS="../libtermcap/libtermcap.a $LIBS"
      ac_cv_search_tgetent="../libtermcap/libtermcap.a"
    fi ;;

Fine, let us start the make process again.

Host:# make
...
...
make[4]: Leaving directory `/home/smp383/mips-4.3/bin/gdb-7.1/gdb/gdbserver'
make[3]: Leaving directory `/home/smp383/mips-4.3/bin/gdb-7.1/gdb'
make[2]: Leaving directory `/home/smp383/mips-4.3/bin/gdb-7.1/gdb'
make[1]: Nothing to be done for `all-target'.
make[1]: Leaving directory `/home/smp383/mips-4.3/bin/gdb-7.1'
Host:#

Excellent, the cross compilation process has been completed. Let's check the generated
binary is MIPS compatible or not.

Host:# cd gdb
Host:# file gdb
gdb: ELF 32-bit LSB executable, MIPS, MIPS32 rel2 version 1, for GNU/Linux 2.6.12,
dynamically linked (uses shared libs), not stripped
Host:#

It seems everything so far is fine. Let us test it in MIPS environment.

tango3[gdb-7.1]# cd gdb
tango3[gdb]# ./gdb
GNU gdb (GDB) 7.1
Copyright (C) 2010 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later
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 "mips-linux-gnu".
For bug reporting instructions, please see:
.
Setting up the environment for debugging gdb.
No symbol table is loaded.  Use the "file" command.
Make breakpoint pending on future shared library load? (y or [n])
[answered N; input not from terminal]
No symbol table is loaded.  Use the "file" command.
Make breakpoint pending on future shared library load? (y or [n])
[answered N; input not from terminal]
/root/cawan/mips-4.3/bin/gdb-7.1/gdb/.gdbinit:8: Error in sourced command file:
No breakpoint number 0.
(gdb)

Excellent, the GDB version 7.1 is successfully running in our MIPS platform now.



pdf version:

http://www.scribd.com/doc/114002450/How-to-Cross-Compile-GDB-and-Run-in-Embedded-System