GDB
From ArmadeusWiki
On this page you will find all you need to debug your userspace applications running on your Armadeus board.
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Note: First of all, be sure to have installed the Toolchain on your Host. |
Contents
Compile your program with debug symbols
- Use -g option of gcc:
$ make shell_env $ . armadeus_env.sh $ export PATH=$PATH:$ARMADEUS_TOOLCHAIN_PATH $ arm-linux-gcc -g -o hello hello.c
- If you have a Makefile for your project, you probably have a CFLAGS variable, so add it -g. Ex:
CFLAGS=-W -Wall -g
Debugging a program running on your APF remotely from your Host (through Ethernet)
- On the target launch your program like that:
# gdbserver 192.168.0.2:2345 program [args]
192.168.0.2 is the IP address of your Host and 2345 the port number to use (examples).
- On your Host launch:
[]$ arm-linux-gdb program (gdb) set solib-absolute-prefix ./buildroot/output/build/staging_dir/ (gdb) target remote 192.168.0.10:2345
192.168.0.10 is the address of your target
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Note: Only continue / c can be used to start the program, because it is already running when you launch GDB on your host. |
(gdb) break main (gdb) continue ... (gdb) next ...
- If the program is already running, gdbserver can attach itself to the process, if you give him its PID
# ps ... get process PID # gdbserver 192.168.0.2:2345 --attach PID
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Note: Core dump analysis doesn't seem to work in this use case (ie on the Host with arm-linux-gdb) !! |
Debugging directly on your APF (may require more memory)
- You have to build gdb for the target:
$ make menuconfig
Toolchain --->
*** Gdb Options ***
[*] Build gdb debugger for the Target
$ make
Then you can either reflash your rootfs, or copy $ARMADEUS_ROOTFS_DIR/usr/bin/gdb to your board, to a SD or to a NFS export.
- After installation, launch gdb on your APF:
# gdb your_prog
If you need argument passing:
# gdb --args your_prog your_args
To debug a Core dump:
# gdb your_prog -c your_core_file
Troubleshots
pthread debugging
- If you see that kind of error message when using gdb:
dlopen failed on 'libthread_db.so.1' - File not found GDB will not be able to debug pthreads.
Don't worry ! ;-)
libthread_db.so (db == debug) is a library that is needed when you want to debug programs using pthread. You will have to reconfigure the uClibc to get it build:
$ make uclibc-menuconfig
General Library Settings --->
...
[*] POSIX Threading Support
[*] Build pthreads debugging support
...
- Save your uClibc config and make it standard for next build:
$ cp buildroot/output/toolchain/uClibc-0.9.30.3/.config buildroot/target/device/armadeus/apfXX/uClibc.config.arm
- Then rebuild all the toolchain (this will erase your local modifications !!)
$ rm -rf buildroot/output $ make
