From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 8254 invoked by alias); 10 Dec 2018 17:33:31 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 8245 invoked by uid 89); 10 Dec 2018 17:33:31 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=4.8 required=5.0 tests=BAYES_50,BODY_8BITS,GARBLED_BODY,RCVD_IN_DNSWL_NONE,SPF_PASS,TIME_LIMIT_EXCEEDED autolearn=unavailable version=3.3.2 spammy=watched, february, February, Produce X-HELO: mail-pg1-f194.google.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dabbelt-com.20150623.gappssmtp.com; s=20150623; h=date:subject:in-reply-to:cc:from:to:message-id:mime-version :content-transfer-encoding; bh=iNwSVe5DTkBspyaH6+Pps94YZVN37voXXPq4PdhWSf8=; b=KbxzXigAxwC12shHftUowg2wr+pZD3VkFCflFAh5Ob6sL30voHZX/umL20+kAp5buB TbII0ziqHUL19zYMl/pC4qBBMHXeOAvuFeVVn476x9/UIorVwiWR4qyajsJXyo9c7A9r c6Xhocr6Pgh2lPuuq5g/AX4+cLhcNHviH4C3FzDg83F+49ggu3I9ykZr0XXUjxVUo8mC /O1ufaC9NKmTmHOTYuitMjoos9q6QcSlUP6AMN4EzJSGFEPHyF6zAsivbi10fNJDM7zW VsmGC6Q7AeOt4r9foZ8u76rFkJYK5PVF3E/YkhwCzv4e1tvEHKq1CODMcBj68zTeju4V Vlqw== Return-Path: Date: Mon, 10 Dec 2018 17:37:00 -0000 X-Google-Original-Date: Mon, 10 Dec 2018 09:32:50 PST (-0800) Subject: Re: [PATCH v4 00/10] RISC-V glibc port for the 32-bit In-Reply-To: CC: joseph@codesourcery.com, Arnd Bergmann , Alistair Francis , Darius Rad , Andrew Waterman , dj@redhat.com, libc-alpha@sourceware.org, zong@andestech.com From: Palmer Dabbelt To: zongbox@gmail.com Message-ID: Mime-Version: 1.0 (MHng) Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-SW-Source: 2018-12/txt/msg00323.txt.bz2 On Mon, 10 Dec 2018 01:38:59 PST (-0800), zongbox@gmail.com wrote: > Palmer Dabbelt 於 2018年12月9日 週日 上午4:09寫道： >> >> On Fri, 07 Dec 2018 01:51:46 PST (-0800), zongbox@gmail.com wrote: >> > Joseph Myers 於 2018年12月4日 週二 上午2:04寫道： >> >> >> >> Could you confirm the ABI entries that would be added to >> >> ? >> > >> > We would need to add the ABI entries as following: >> > 32-bit, soft-float, LE: /lib/ld-linux-riscv32-ilp32.so.1 >> > 32-bit, hard-float, LE: /lib/ld-linux-riscv32-ilp32d.so.1 >> > >> >> Could you confirm the minimum upstream kernel version that supports 32-bit >> >> RISC-V with the syscall ABI that will remain supported long-term? Is it >> >> 4.15, or a later version? (If a later version, arch_minimum_kernel needs >> >> to be set accordingly.) >> >> >> > I had checked with Palmer, and Palmer would confirm this here. >> >> Sorry for the confusion. A few of us sat down at the toolchain microconference >> at Plumbers and we decided it would be best to wait until the 32-bit Linux port >> is ready to support a 64-bit time_t ABI. This isn't ready yet and won't be >> ready in time for the glibc freeze. >> >> The options considered were to: >> >> * Submit this port, which matches the current Linux ABI. This has been stable >> since 4.15. >> * Try to push all the 64-bit time_t stuff into the next releases, so Linux >> 4.21 (which is not out yet). >> * Wait until after the next glibc release and then submit the port, ideally >> also against Linux 4.21. >> >> We all decided to wait, as if we submit this now we'll end up with a RV32I >> glibc port that's 32-bit time_t. We'd then have to go do another 64-bit time_t >> port along with everyone else, thus making this original port obsolete -- we'd >> have to support the 32-bit time_t port forever, which seems like a headache. >> >> The plan we came up with was to instead: >> >> * Review this port as if it was to be submitted, so we can sort out the issues. >> * Produce an out-of-tree 32-bit time_t port, based on the upcoming glibc >> release, that we can then use the bring up the port of at least one distro. > > Where and how could we put the port? I think it's OK to put it on github. > >> I know OpenEmbedded is coming up for RV32I, which would give me a lot more >> confidence we have an actual working port. >> * Submit the port after the upcoming release in February. >> * Fix both Linux (for 4.21) and our glibc port to use a 64-bit time_t ABI, >> which should be possible at least for all core kernel functionality. >> >> I know Zong was at Plumbers, maybe you missed the tool chain thing? > > Yes, I had watched the video of the topic. I totally agree your point > and suggestion. > I would fix the issues in this version, and then test rv32 port on > Linux 4.21 in the future. > Thanks to Joseph and DJ to pointed out the problems. > >> Is this OK with everyone? > > That is OK with me. OK, sounds good!