From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Lmc6a-0006k9-VK for qemu-devel@nongnu.org; Wed, 25 Mar 2009 19:01:53 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1Lmc6U-0006hF-FJ for qemu-devel@nongnu.org; Wed, 25 Mar 2009 19:01:51 -0400 Received: from [199.232.76.173] (port=47159 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Lmc6U-0006h5-8b for qemu-devel@nongnu.org; Wed, 25 Mar 2009 19:01:46 -0400 Received: from imag.imag.fr ([129.88.30.1]:59176) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1Lmc6T-0006pV-JI for qemu-devel@nongnu.org; Wed, 25 Mar 2009 19:01:45 -0400 Date: Wed, 25 Mar 2009 23:58:06 +0100 From: Philippe Waille Subject: Re: [Qemu-devel] qemu-user/gdbstub : gdb remote pipe connexion addition ? Message-ID: <20090325225806.GA21100@otto.imag.fr> References: <20090320145101.GA20641@otto.imag.fr> <200903241252.57755.paul@codesourcery.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200903241252.57755.paul@codesourcery.com> Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org On Tue, Mar 24, 2009 at 12:52:57PM +0000, Paul Brook wrote: > For userspace emulation using stdio IMHO doesn't make a whole lot of sense. > The user application is almost certainly already using that for something > else. This is different to e.g. gdbserver and openocd where the debug stub is > a separate process from the user application. Ok if qemu in user mode only targets cross develop/debug/benchmark of complete applications in C/C++/JAVA/... for an embeded target system. But I consider other another usage. An efficient user mode simulator such as qemu is also very interesting for (any ISA != IA32) assembly langage teaching. I would use it to replace the gdb builtin ARM simulator (rdi targeti, removed from gdb since 6.4). Students learning assembly langage programming ususally write very small programs (n!, sum of array elements,...) and will only use a few basic stdio primitives (printf/scanf/putchar/getchar) already translated in gdb remote file I/O by qemu gbstub. Nothing else : they don't call pipe, dup or ioctl from assembler code ! Qemu-arm user mode with socket based gdb connexion is already a valuable tool, but gdb remote pipe connexion would allow cleaner and easier gdb starting/configuration/termination procedures (script files), especially on shared POSIX servers. Note : I would event be interested by ARM semihosting on gdb file I/O protocol through openocd and JTAG interfaces, ... but its too much work for the benefits. Best regards Ph. W. -- ----------------------------------------------------------------------------- Philippe WAILLE email : Philippe.Waille@imag.fr IMAG ID (Informatique et distribution) Tel : 04 76 61 20 13 ENSIMAG - antenne de Montbonnot Foreign : 33 4 76 61 20 13 INOVALLEE Fax : 04 76 61 20 99 51, avenue Jean Kuntzmann 38330 MONTBONNOT SAINT MARTIN