aaa gdb scratchpad

Hello

arm-python-config

#! /bin/sh

if [ -z "${PI2_ROOT}" ]; then
        echo "PI2_ROOT is not set!" >&2
        exit 1
fi

if [ $# -ne 2 ]
then
        echo "Bad # args.  Blech!" >&2
        exit 1
fi

# The first argument is the path to python-config.py, ignore it.

case "$2" in
--includes) echo "-I${PI2_ROOT}/usr/include/python3.4m" ;;
--ldflags) echo "-lpython3.4m -lpthread -ldl -lutil -lm -Xlinker -export-dynamic -Wl,-O1 -Wl,-Bsymbolic-functions" ;;
--exec-prefix) echo "/usr" ;;
*) echo "Bad arg $2.  Blech!" >&2 ; exit 1 ;;
esac

exit 0

cross-compile gdb for pi2

1. Mount the pi2's root fs on the host.  Set the PI2_ROOT env variable
   to where you want it mounted, so we can refer to it later.
   
   host$ export PI2_ROOT=/tmp/rpi-root
   host$ export PI2_HOST=142.133.111.232
   host$ mkdir -p ${PI2_ROOT} && sshfs -o transform_symlinks simark@${PI2_HOST}:/ ${PI2_ROOT}

2. Create a fake python-config file for gdb's configure to use (see
   https://sourceware.org/gdb/wiki/CrossCompilingWithPythonSupport).
   Set the ARM_PYTHON_CONFIG shell variable so we can refer to it later
   (it doesn't need to be exported).
   
   host$ ARM_PYTHON_CONFIG=/home/emaisin/src/arm-python-config
   
   You can use the attached arm-python-config file as a base.  The flags
   to use are found by running on the pi2:
   
   pi2$ /usr/lib/python3.4/config-3.4m-arm-linux-gnueabihf/python-config.py --includes
   pi2$ /usr/lib/python3.4/config-3.4m-arm-linux-gnueabihf/python-config.py --ldflags
   pi2$ /usr/lib/python3.4/config-3.4m-arm-linux-gnueabihf/python-config.py --exec-prefix

3. Configure and build binutils-gdb

   host$ ~/src/binutils-gdb/configure \
           --host=arm-linux-gnueabihf \
           CFLAGS="--sysroot ${PI2_ROOT} -g3 -O0" \
           LDFLAGS="--sysroot ${PI2_ROOT}" \
           --disable-ld --disable-gold --disable-gas --disable-binutils --disable-gprof --disable-sim \
           --with-python=${ARM_PYTHON_CONFIG} --with-expat --enable-tui

4. Mount host build directory on the pi2 and run gdb

  pi2$ mkdir -p /home/simark/build/binutils-gdb && sshfs -o cache=no emaisin@142.133.110.144:/home/emaisin/build/binutils-gdb-arm /home/simark/build/binutils-gdb
  pi2$ /home/simark/build/binutils-gdb/gdb/gdb --data-directory /home/simark/build/binutils-gdb/gdb/data-directory

gdb common configure lines

Normal:
~/src/binutils-gdb/configure \
  CC="ccache gcc" \
  CXX="ccache g++" \
  --enable-targets=all \
  CFLAGS="-g3 -O0" \
  CXXFLAGS="-g3 -O0" \
  --with-python=/usr/bin/python3 \
  --enable-tui \
  --with-expat \
  --disable-ld --disable-gold --disable-gas --disable-binutils --disable-gprof

C++:
~/src/binutils-gdb/configure \
  --enable-build-with-cxx \
  CC="ccache gcc" \
  CXX="ccache g++" \
  --enable-targets=all \
  CFLAGS="-g3 -O0" \
  CXXFLAGS="-g3 -O0" \
  --with-python=/usr/bin/python3 \
  --enable-tui \
  --with-expat \
  --disable-ld --disable-gold --disable-gas --disable-binutils --disable-gprof

ARM cross debugger:
~/src/binutils-gdb/configure --disable-ld --disable-gold --disable-binutils --disable-gprof --disable-sim \
    --with-expat --enable-tui --with-python=/usr/bin/python3 \
    --target=arm-linux-gnueabihf CFLAGS="-g3 -O0" CXXFLAGS="-g3 -O0"
~/src/binutils-gdb/gdb/gdbserver/configure

native-gdbserver.exp

# gdbserver running remotely over ssh

load_generic_config "gdbserver"

process_multilib_options ""

# The default compiler for this target.
#set_board_info compiler  "[find_gcc]"
# If gdbserver runs in a cross-target arch, the testsuite should use a cross-compiler
set_board_info compiler  "arm-linux-gnueabihf-gcc"
set_board_info c++compiler  "arm-linux-gnueabihf-g++"

set_board_info rsh_prog "/usr/bin/ssh"
set_board_info rcp_prog "/usr/bin/scp"
set_board_info protocol standard
set_board_info username simark
set_board_info hostname 142.133.111.135

# Path to the gdbserver executable on target board.
set_board_info gdb_server_prog /home/simark/gdbserver
# We will be using the standard GDB remote protocol
set_board_info gdb_protocol "remote"

# Name of the computer whose socket will be used, if required.
set_board_info sockethost "142.133.111.135:"

# Port ID to use for socket connection
#set_board_info gdb,socketport "4004"

# Use techniques appropriate to a stub
set_board_info use_gdb_stub 1

# This gdbserver can only run a process once per session.
set_board_info gdb,do_reload_on_run 1

# There's no support for argument-passing (yet).
set_board_info noargs 1

# Can't do input (or output) in the current gdbserver.
set_board_info gdb,noinferiorio 1

# Can't do hardware watchpoints, in general (it depends on gdbserver support for your target arch)
set_board_info gdb,no_hardware_watchpoints 1

simple test program

#include <stdio.h>

int loop(int n) {
	int i;
	int total = 0;

	for (i = 0; i < n; i++) {
		total += i;
	}

	return total;
}

int main() {
	int res;

	res = loop(20);

	printf("Result is %d\n", res);

	return 0;
}