From 1614bf6be7766271f69bea245b37972802e13395 Mon Sep 17 00:00:00 2001 From: Thomas Petazzoni Date: Mon, 5 May 2014 11:25:51 +0200 Subject: [PATCH] docs/manual: document how to use the cross debugger Signed-off-by: Thomas Petazzoni [ThomasDS: some rewording, add path prefix in example] Signed-off-by: Thomas De Schampheleire Signed-off-by: Peter Korsgaard --- docs/manual/advanced.txt | 2 + docs/manual/using-buildroot-debugger.txt | 53 ++++++++++++++++++++++++ 2 files changed, 55 insertions(+) create mode 100644 docs/manual/using-buildroot-debugger.txt diff --git a/docs/manual/advanced.txt b/docs/manual/advanced.txt index 0ad79f7b1b..05c5242453 100644 --- a/docs/manual/advanced.txt +++ b/docs/manual/advanced.txt @@ -5,6 +5,8 @@ include::using-buildroot-toolchain.txt[] +include::using-buildroot-debugger.txt[] + include::ccache-support.txt[] include::download-location.txt[] diff --git a/docs/manual/using-buildroot-debugger.txt b/docs/manual/using-buildroot-debugger.txt new file mode 100644 index 0000000000..962ecf7a63 --- /dev/null +++ b/docs/manual/using-buildroot-debugger.txt @@ -0,0 +1,53 @@ +// -*- mode:doc; -*- +// vim: set syntax=asciidoc: + +=== Using +gdb+ in Buildroot + +Buildroot allows to do cross-debugging, where the debugger runs on the +build machine and communicates with +gdbserver+ on the target to +control the execution of the program. + +To achieve this: + +* If you are using an _internal toolchain_ (built by Buildroot), you + must enable +BR2_PACKAGE_HOST_GDB+, +BR2_PACKAGE_GDB+ and + +BR2_PACKAGE_GDB_SERVER+. This ensures that both the cross gdb and + gdbserver get built, and that gdbserver gets installed to your target. + +* If you are using an _external toolchain_, you should enable + +BR2_TOOLCHAIN_EXTERNAL_GDB_SERVER_COPY+, which will copy the + gdbserver included with the external toolchain to the target. If your + external toolchain does not have a cross gdb or gdbserver, it is also + possible to let Buildroot build them, by enabling the same options as + for the _internal toolchain backend_. + +Now, to start debugging a program called +foo+, you should run on the +target: + +---------------------------- +gdbserver :2345 foo +---------------------------- + +This will cause +gdbserver+ to listen on TCP port 2345 for a connection +from the cross gdb. + +Then, on the host, you should start the cross gdb using the following +command line: + +---------------------------- +/output/host/usr/bin/-gdb -x /output/staging/usr/share/buildroot/gdbinit foo +---------------------------- + +Of course, +foo+ must be available in the current directory, built +with debugging symbols. Typically you start this command from the +directory where +foo+ is built (and not from +output/target/+ as the +binaries in that directory are stripped). + +The +/output/staging/usr/share/buildroot/gdbinit+ file will tell the +cross gdb where to find the libraries of the target. + +Finally, to connect to the target from the cross gdb: + +---------------------------- +(gdb) target remote :2345 +---------------------------- -- 2.30.2