From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hYxF3-0002Tn-Q6 for barebox@lists.infradead.org; Thu, 06 Jun 2019 18:36:03 +0000 Date: Thu, 6 Jun 2019 20:35:57 +0200 From: Roland Hieber Message-ID: <20190606183557.enmjhh34jzialmwq@pengutronix.de> References: <20190604143851.11928-1-r.czerwinski@pengutronix.de> <20190604143851.11928-3-r.czerwinski@pengutronix.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190604143851.11928-3-r.czerwinski@pengutronix.de> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [PATCH 3/3] add gdb helper scripts to load barebox symbols To: Rouven Czerwinski Cc: barebox@lists.infradead.org On Tue, Jun 04, 2019 at 04:38:53PM +0200, Rouven Czerwinski wrote: > Add a gdb script with two helper functions which use the new > pbl_barebox_break symbol to calculate the current barebox load address > on the device and loads a barebox ELF file to this address. > > Signed-off-by: Rouven Czerwinski > --- > Documentation/user/debugging.rst | 21 +++++++++++ > Documentation/user/user-manual.rst | 1 + > common/Kconfig | 9 +++++ > scripts/gdb/helper.py | 60 ++++++++++++++++++++++++++++++ > 4 files changed, 91 insertions(+) > create mode 100644 Documentation/user/debugging.rst > create mode 100644 scripts/gdb/helper.py > > diff --git a/Documentation/user/debugging.rst b/Documentation/user/debugging.rst > new file mode 100644 > index 0000000000..15cb439043 > --- /dev/null > +++ b/Documentation/user/debugging.rst > @@ -0,0 +1,21 @@ > +Debugging with OpenOCD > +====================== > + > +Barebox can be configured to break on prebootloader and main barebox entry. This > +breakpoint can not be resumed and will stop the board to allow the user to > +attach a JTAG debugger with OpenOCD. Additionally, barebox provides helper > +scripts to load the symbols from the ELF binaries. > +The python scripts require `pyelftools`. > +To load the scripts into your gdb session, run the following command in the > +barebox directory: > + > +.. code-block:: none > + > + (gdb) source scripts/gdb/helper.py > + > +This makes two new commands available in gdb, `bb-load-symbols` and > +`bb-skip-break`. `bb-load-symbols` can load either the main `barebox` file or > +one of the .pbl files in the image directories. The board needs to be stopped in > +either the prebootloader or main barebox breakpoint, and gdb needs to be > +connected to OpenOCD. To continue booting the board, `bb-skip-break` jumps over > +the breakpoint and continues the barebox execution. > diff --git a/Documentation/user/user-manual.rst b/Documentation/user/user-manual.rst > index 516b760b1b..f04981c3f0 100644 > --- a/Documentation/user/user-manual.rst > +++ b/Documentation/user/user-manual.rst > @@ -33,6 +33,7 @@ Contents: > system-reset > state > random > + debugging > > * :ref:`search` > * :ref:`genindex` > diff --git a/common/Kconfig b/common/Kconfig > index 4124857a0a..c766e1ef64 100644 > --- a/common/Kconfig > +++ b/common/Kconfig > @@ -1252,6 +1252,15 @@ config PBL_BREAK > If this enabled, barebox will be compiled with BKPT instruction > on early pbl init. This option be used only with JTAG debugger! > > +config GDB_SCRIPTS > + bool "Provide GDB scripts for barebox debugging" > + help > + This creates the required links to GDB helper scripts in the > + build directory. If you load barebox into gdb, the helper > + scripts will be automatically imported by gdb as well, and > + additional functions are available to analyze a Linux kernel > + instance. > + > endmenu This symbol is not used in any way, as far as I can see. - Roland > > config HAS_DEBUG_LL > diff --git a/scripts/gdb/helper.py b/scripts/gdb/helper.py > new file mode 100644 > index 0000000000..4041789890 > --- /dev/null > +++ b/scripts/gdb/helper.py > @@ -0,0 +1,60 @@ > +#!/usr/bin/env python > + > +import gdb > + > +try: > + from elftools.elf.elffile import ELFFile > + from elftools.common.exceptions import ELFError > +except ImportError: > + gdb.write("The barebox helper requires pyelftools\n", gdb.STDERR) > + exit(1) > + > + > +class BBSymbols(gdb.Command): > + > + def __init__(self): > + super(BBSymbols, self).__init__("bb-load-symbols", gdb.COMMAND_FILES, > + gdb.COMPLETE_FILENAME) > + > + def invoke(self, argument, from_tty): > + path = argument > + f = open(path, 'rb') > + > + try: > + elf = ELFFile(f) > + except ELFError: > + gdb.write("Selected file is not an ELF file\n", gdb.STDERR) > + return > + > + section = elf.get_section_by_name(".symtab") > + if section is None: > + gdb.write("Section .symtab not found\n", gdb.STDERR) > + return > + symbol = section.get_symbol_by_name("pbl_barebox_break") > + if not symbol: > + gdb.write("Symbol pbl_barebox_break in section {} in file {} not found\n" > + .format(section.name, self.path), gdb.STDERR) > + return > + symbol = symbol[0] > + pc = gdb.parse_and_eval("$pc") > + symbol_address = int(symbol.entry.st_value) > + address = int(pc) - symbol_address + 1 > + gdb.execute("symbol-file") > + gdb.execute("add-symbol-file {} {}".format(path, address)) > + > + > +BBSymbols() > + > + > +class BBSkip(gdb.Command): > + > + def __init__(self): > + super(BBSkip, self).__init__("bb-skip-break", gdb.COMMAND_BREAKPOINTS) > + > + def invoke(self, arg, from_tty): > + pc = gdb.parse_and_eval("$pc") > + nop_address = int(pc) + 2 > + gdb.execute("jump *{}".format(nop_address)) > + > + > +BBSkip() > -- > 2.21.0 > > > _______________________________________________ > barebox mailing list > barebox@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/barebox > -- Roland Hieber | r.hieber@pengutronix.de | Pengutronix e.K. | https://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim | Phone: +49-5121-206917-5086 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox