e1c3a37375
On ARM, PikeOS does not support hardware single step, causing various
semi-random errors when trying to next/step over some user code. So
this patch changes this target to use software-single-step instead.
The challenge is that, up to now, the PikeOS target was in all respects
identical to a baremetal target as far as GDB was concerned, meaning
we were using the baremetal osabi for this target too. This is no longer
possible, and we need to introduce a new OSABI variant. Unfortunately,
there isn't anything in the object file that would allow us to
differentiate between the two platforms. So we have to rely on a
heuristic instead, where we look for some known symbols that are
required in a PikeOS application (these symbols are expected to be
defined by the default linker script, and correspond to routines used
to allocate the application stack).
For the long run, the hope is that the stub implementation provided
by PikeOS is enhanced so that it includes vContSupported+ to the
$qSupported query, and then that the reply to the "vCont?" query
only return support for "continue" operations (thus exclusing "step"
operations). We could then use that information to reliably determine
at connection time that the target does not support single-stepping
and therefore automatically turn software single-stepping automatically
based on it.
gdb/ChangeLog:
* defs.h (enum gdb_osabi): Add GDB_OSABI_PIKEOS.
* osabi.c (gdb_osabi_names): Add name for GDB_OSABI_PIKEOS.
* arm-pikeos-tdep.c: New file.
* configure.tgt: Add arm-pikeos-tdep.o to the case of ARM
embedded system.
* Makefile.in (ALL_TARGET_OBS): Add arm-pikeos-tdep.o.
Tested on arm-pikeos and arm-elf using AdaCore's testsuite.
We also evaluated it on armhf-linux as a cross platform.
README for GNU development tools This directory contains various GNU compilers, assemblers, linkers, debuggers, etc., plus their support routines, definitions, and documentation. If you are receiving this as part of a GDB release, see the file gdb/README. If with a binutils release, see binutils/README; if with a libg++ release, see libg++/README, etc. That'll give you info about this package -- supported targets, how to use it, how to report bugs, etc. It is now possible to automatically configure and build a variety of tools with one command. To build all of the tools contained herein, run the ``configure'' script here, e.g.: ./configure make To install them (by default in /usr/local/bin, /usr/local/lib, etc), then do: make install (If the configure script can't determine your type of computer, give it the name as an argument, for instance ``./configure sun4''. You can use the script ``config.sub'' to test whether a name is recognized; if it is, config.sub translates it to a triplet specifying CPU, vendor, and OS.) If you have more than one compiler on your system, it is often best to explicitly set CC in the environment before running configure, and to also set CC when running make. For example (assuming sh/bash/ksh): CC=gcc ./configure make A similar example using csh: setenv CC gcc ./configure make Much of the code and documentation enclosed is copyright by the Free Software Foundation, Inc. See the file COPYING or COPYING.LIB in the various directories, for a description of the GNU General Public License terms under which you can copy the files. REPORTING BUGS: Again, see gdb/README, binutils/README, etc., for info on where and how to report problems.