54 lines
1.9 KiB
Plaintext
54 lines
1.9 KiB
Plaintext
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// -*- mode:doc; -*-
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// vim: set syntax=asciidoc:
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=== Using +gdb+ in Buildroot
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Buildroot allows to do cross-debugging, where the debugger runs on the
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build machine and communicates with +gdbserver+ on the target to
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control the execution of the program.
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To achieve this:
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* If you are using an _internal toolchain_ (built by Buildroot), you
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must enable +BR2_PACKAGE_HOST_GDB+, +BR2_PACKAGE_GDB+ and
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+BR2_PACKAGE_GDB_SERVER+. This ensures that both the cross gdb and
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gdbserver get built, and that gdbserver gets installed to your target.
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* If you are using an _external toolchain_, you should enable
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+BR2_TOOLCHAIN_EXTERNAL_GDB_SERVER_COPY+, which will copy the
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gdbserver included with the external toolchain to the target. If your
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external toolchain does not have a cross gdb or gdbserver, it is also
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possible to let Buildroot build them, by enabling the same options as
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for the _internal toolchain backend_.
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Now, to start debugging a program called +foo+, you should run on the
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target:
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----------------------------
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gdbserver :2345 foo
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----------------------------
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This will cause +gdbserver+ to listen on TCP port 2345 for a connection
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from the cross gdb.
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Then, on the host, you should start the cross gdb using the following
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command line:
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----------------------------
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<buildroot>/output/host/usr/bin/<tuple>-gdb -x <buildroot>/output/staging/usr/share/buildroot/gdbinit foo
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----------------------------
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Of course, +foo+ must be available in the current directory, built
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with debugging symbols. Typically you start this command from the
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directory where +foo+ is built (and not from +output/target/+ as the
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binaries in that directory are stripped).
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The +<buildroot>/output/staging/usr/share/buildroot/gdbinit+ file will tell the
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cross gdb where to find the libraries of the target.
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Finally, to connect to the target from the cross gdb:
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----------------------------
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(gdb) target remote <target ip address>:2345
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----------------------------
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