From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.polymtl.ca (smtp.polymtl.ca [132.207.4.11]) by sourceware.org (Postfix) with ESMTPS id C541B3851C0B for ; Wed, 13 May 2020 14:45:28 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org C541B3851C0B Received: from simark.ca (simark.ca [158.69.221.121]) (authenticated bits=0) by smtp.polymtl.ca (8.14.7/8.14.7) with ESMTP id 04DEjJ8P027625 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 13 May 2020 10:45:24 -0400 DKIM-Filter: OpenDKIM Filter v2.11.0 smtp.polymtl.ca 04DEjJ8P027625 Received: from [10.0.0.193] (unknown [192.222.164.54]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by simark.ca (Postfix) with ESMTPSA id D880C1E5F9; Wed, 13 May 2020 10:45:18 -0400 (EDT) Subject: Re: GDBserver ports cleanup To: Pedro Alves , Christian Biesinger Cc: "gdb-patches@sourceware.org" References: <0d22aed0-9a24-7369-795d-587ec6b99d11@polymtl.ca> <6046157a-80fc-95d1-ff06-0892343c6f34@redhat.com> From: Simon Marchi Message-ID: Date: Wed, 13 May 2020 10:45:18 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <6046157a-80fc-95d1-ff06-0892343c6f34@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: tl Content-Transfer-Encoding: 7bit X-Poly-FromMTA: (simark.ca [158.69.221.121]) at Wed, 13 May 2020 14:45:19 +0000 X-Spam-Status: No, score=-8.0 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_PASS, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 13 May 2020 14:45:30 -0000 On 2020-05-13 8:01 a.m., Pedro Alves wrote: > On 5/12/20 9:26 PM, Christian Biesinger via Gdb-patches wrote: >> On Tue, May 12, 2020 at 11:48 AM Simon Marchi via Gdb-patches > >>> About Windows support for ARM, I don't really know about it. I think that our port >>> was targeting Windows CE [2], which can probably be considered obsolete. However, >>> Windows 10 supposedly runs on ARM [3], so it might be relevant to keep it? I don't really >>> know if the current GDBserver code would help for that or not. In doubt, I won't propose >>> to remove it. >> >> If indeed the win32-arm support handles Windows 10, I think it would >> be good to keep it, but I am not sure it does -- win32-arm-low.cc does >> have these lines: >> /* Correct in either endianness. We do not support Thumb yet. */ >> static const unsigned long arm_wince_breakpoint = 0xe6000010; >> #define arm_wince_breakpoint_len 4 >> >> Note mention of WinCE. Also, I am not so familiar with Thumb but I >> believe that's widely used on ARM these days? >> >> So my vote would be to remove this for now and if someone wants to >> revive it there's the git history. > win32-arm support in gdbserver is only for Windows CE. I was the one > who wrote it, it was the reason I got into GDB hacking in the first > place. :-) There was no Windows for ARM back then. > > I don't object removing it. I haven't built a compiler or gdbserver > for WinCE in years, and I doubt anyone else has^W^W^W^W^W^W^W^W^W^W^W^W > Wow, I just found out that someone forked my old cegcc project, and > updated it based on a much more modern GCC: > https://max.kellermann.name/projects/cegcc/ > I had no idea. Look like he has some local GDB in his github, though > dated from 2016/2018. > > If you do remove it, then you'll want to remove all the code guarded under > _WIN32_WCE in win32-low.cc, and also wincecompat.c. There's also > ARM WinCE support on the GDB side, in arm-wince-tdep.c. > > I'm not sure there's that much salvageable for an eventual Windows for ARM > port. For example, Windows for ARM is strictly Thumb-2, while I don't recall > ever considering Thumb-2 back then. WinCE was FPA, I believe, while Windows > for ARM is VFP. The ABIs are just different, and WinCE is weird beyond belief. > (no "errno", no concept for "current directory", etc.). > > Other than nostalgia for being what got me into GDB, I really won't miss it > myself. Thanks for the storytelling, I enjoyed it :). If removing support for WinCE ends up simplifying win32-low.cc, it is a net gain, since that file is used today. Simon