From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/9699 Path: news.gmane.org!not-for-mail From: Rich Felker Newsgroups: gmane.comp.hardware.lowrisc.devel,gmane.linux.lib.musl.general Subject: Re: [musl] [GSoC2016] A proposal on porting musl to RISC-V Date: Sat, 19 Mar 2016 02:37:49 -0400 Message-ID: <20160319063749.GT21636@brightrain.aerifal.cx> References: NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1458369495 5854 80.91.229.3 (19 Mar 2016 06:38:15 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 19 Mar 2016 06:38:15 +0000 (UTC) Cc: lowrisc-dev@lists.lowrisc.org, musl@lists.openwall.com To: Masanori Ogino Original-X-From: lowrisc-dev-bounces@lists.lowrisc.org Sat Mar 19 07:38:07 2016 Return-path: Envelope-to: gchld-lowrisc-dev@m.gmane.org Original-Received: from bagpuss.pepperfish.net ([148.251.8.16]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1ahAWV-00082q-Bs for gchld-lowrisc-dev@m.gmane.org; Sat, 19 Mar 2016 07:38:07 +0100 Original-Received: from platypus.pepperfish.net (unknown [10.112.100.20]) by bagpuss.pepperfish.net (Postfix) with ESMTP id 2ECE996B; Sat, 19 Mar 2016 06:38:06 +0000 (GMT) Original-Received: from ip6-localhost ([::1] helo=platypus.pepperfish.net) by platypus.pepperfish.net with esmtp (Exim 4.80 #2 (Debian)) id 1ahAWU-0007J7-2h; Sat, 19 Mar 2016 06:38:06 +0000 Original-Received: from inmail0 ([10.112.100.10] helo=mx0.pepperfish.net) by platypus.pepperfish.net with esmtp (Exim 4.80 #2 (Debian)) id 1ahAWS-0007J1-38 for ; Sat, 19 Mar 2016 06:38:04 +0000 Original-Received: from 216-12-86-13.cv.mvl.ntelos.net ([216.12.86.13] helo=brightrain.aerifal.cx) by mx0.pepperfish.net with esmtp (Exim 4.80) (envelope-from ) id 1ahAWO-0005wd-R8 for lowrisc-dev@lists.lowrisc.org; Sat, 19 Mar 2016 06:38:03 +0000 Original-Received: from dalias by brightrain.aerifal.cx with local (Exim 3.15 #2) id 1ahAWD-0005sX-00; Sat, 19 Mar 2016 06:37:49 +0000 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-Spam-Score: -1.9 X-Spam-Score-int: -18 X-Spam-Bar: - X-Scanned-By: pepperfish.net, Sat, 19 Mar 2016 06:38:03 +0000 X-Spam-Report: Content analysis details: (-1.9 points) pts rule name description ---- ---------------------- -------------------------------------------------- -1.0 PPF_USER_AGENT_MUTT User-Agent: contains Mutt (Mutt isn't a spam tool) -0.5 PPF_USER_AGENT User-Agent: exists 0.5 TVD_RCVD_IP Message was received from an IP address -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] 1.0 RDNS_DYNAMIC Delivered to internal network by host with dynamic-looking rDNS X-ACL-Warn: message may be spam X-Scan-Signature: f002631632f2cb3301b65fcd1d45d147 X-BeenThere: lowrisc-dev@lists.lowrisc.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Hardware or software development discussion for lowRISC List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: lowrisc-dev-bounces@lists.lowrisc.org Errors-To: lowrisc-dev-bounces@lists.lowrisc.org Xref: news.gmane.org gmane.comp.hardware.lowrisc.devel:330 gmane.linux.lib.musl.general:9699 Archived-At: On Wed, Mar 16, 2016 at 10:22:31AM +0900, Masanori Ogino wrote: > Hello, > > I published an early draft of my Google Summer of Code 2016 proposal. > You can get the draft from: > https://github.com/omasanori/gsoc2016-proposal . > > Check https://github.com/omasanori/gsoc2016-proposal/releases/tag/rev1 > if you want a PDF file of this revision. > > Any comment would be appreciated. Feel free to send comments on MLs or GitHub. Looks very good! Some comments: In regards to your schedule, do you plan to do both rv32 and rv64 (and some 'subarch' ABI variants for both) in parallel from the beginning? I think it might make sense to get one (whatever is easiest) to the point where you can do some meaningful testing before working on them all, but I'd be happy to hear your thoughts on what approach works best for you. One thing to keep in mind (not sure if you're aware of it yet) is that there's an in-progress port, now linked from the lowrisc.org project ideas page, by another student who's interested in applying. Please don't be discouraged by that; the reason I'm mentioning it is just that I think anyone applying should either be planning to use the work that's already done (being careful to properly document authorship) or have a good explanation for why they're not going to. For your proposal, this probably means greatly reducing the number of weeks to be spent on getting the port basically up and running and dedicating more time to the extended deliverables. That's actually a good thing because I don't think you've allocated as much time for the extended deliverables as they might take. For example, for the vdso stuff, if you plan to do the actual kernel patches, that's going to require familiarizing yourself with kernel hacking if you're not already. And hooking it up to GCC for the compiler to use with -mno-atomic (rather than just having libc use it internally) requires some GCC hacking _and_ establishing some ABI for the GCC-generated code to get to the vdso (probably via libc). Hope these comments help, and sorry for not getting back to you sooner. I've had a busy week. Rich