From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/10022 Path: news.gmane.org!not-for-mail From: Szabolcs Nagy Newsgroups: gmane.linux.lib.musl.general Subject: Re: porting musl to RISCV-64 Date: Wed, 11 May 2016 19:28:47 +0200 Message-ID: <20160511172847.GC22574@port70.net> References: <20160511112518.GB22574@port70.net> Reply-To: musl@lists.openwall.com NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1462987751 9061 80.91.229.3 (11 May 2016 17:29:11 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 11 May 2016 17:29:11 +0000 (UTC) To: musl@lists.openwall.com Original-X-From: musl-return-10035-gllmg-musl=m.gmane.org@lists.openwall.com Wed May 11 19:29:05 2016 Return-path: Envelope-to: gllmg-musl@m.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by plane.gmane.org with smtp (Exim 4.69) (envelope-from ) id 1b0XwU-0007iW-4A for gllmg-musl@m.gmane.org; Wed, 11 May 2016 19:29:02 +0200 Original-Received: (qmail 7330 invoked by uid 550); 11 May 2016 17:28:59 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Original-Received: (qmail 7312 invoked from network); 11 May 2016 17:28:59 -0000 Mail-Followup-To: musl@lists.openwall.com Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Xref: news.gmane.org gmane.linux.lib.musl.general:10022 Archived-At: * Gry Gunvor [2016-05-11 09:40:42 -0700]: > Here's another way to put my question: I've already written my own > ghetto riscv-64 libc for synchronous programming (no threads, signals) > by writing my own version of what you call syscall_arch.h. Therefore, > how hard would it be to factor musl so that syscall_arch.h was all I > was depending on that is arch dependent? It seems that should get me the previous riscv port attempt might be enough for you https://github.com/lluixhi/musl-riscv but i've never used any of the riscv stuff. > a lot of what libc provides. I would want that if I attempt to > compile a program that does more than that, say, attempts to use > threads/signals/something-weird that I just get a compile-time error. > Here's a naive plan: > > * grep for the inclusion of the other header files in arch other than > syscall_arch.h; > > * for .c files, comment them out in the makefile; > > * for .h files, insert an #error directive. > > What will go wrong? > there are lot of subtle issues that may or may not matter for you. > Gry > > > On Wed, May 11, 2016 at 9:32 AM, Gry Gunvor wrote: > > On Wed, May 11, 2016 at 4:25 AM, Szabolcs Nagy wrote: > > > >> newlib is for baremetal development, you don't > >> need to use threading with it > > > > It's attempt at reentrancy support is causing me problems. > > > >> musl now has 32bit mips, mips64 and mipsn32 support as well. > >> these are different abis so they have to be separate ports, > >> same is true for the riscv targets. > > > > Your documentation does not seem to mention the MIPS64 port, but now > > that I look in arch, I see the directory for it. > > > >> there is a google summer of code project to add riscv support > >> http://www.openwall.com/lists/musl/2016/04/27/3 > >> i think it is supposed to provide a working port within 1-2 > >> months (?) so if you can wait you don't need to do much work. > > > > Suppose I can't wait and I attempt this myself. Right now I'm just > > trying to get a generic libc working. I do not want to handle > > multi-threading or signals. What can I omit? Are the > > non-portabilities isolated in arch/ ? That is, is there much more to > > it than cloning the arch/mips64 directory and hacking on it? > > > > atomic_arch.h: I think I can make all of these functions empty as I am > > not going to be using multi-threading, right? > > > > crt_arch.h: program startup; what is this doing in a libc > > implementation? doesn't the compiler handle this? > > > > ksigaction.h: sorry, I'm not a hardware person; I suppose different > > hardware has a different default layout for a signal object? so this > > is not a thing determined by kernel software? I don't care to handle > > signals right now anyway. > > > > pthread_arch.h: again, I think I can make all of these functions empty > > as I am not going to be using multi-threading. > > > > reloc.h: I can't figure out what this is. > > > > syscall_arch.h: I've already written this for RISCV-64 (and so have > > the RISCV people). > > > > bits: to what extent is this MIPS64-specific? since there is *no* > > inline assembly, how come arch/generic/ doesn't do here? > > > > Gry