From owner-freebsd-arm@freebsd.org Thu Feb 16 21:09:30 2017 Return-Path: Delivered-To: freebsd-arm@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 63F7DCE20A3 for ; Thu, 16 Feb 2017 21:09:30 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Received: from mail-it0-x22f.google.com (mail-it0-x22f.google.com [IPv6:2607:f8b0:4001:c0b::22f]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 2D9751AF4 for ; Thu, 16 Feb 2017 21:09:30 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Received: by mail-it0-x22f.google.com with SMTP id x75so40239477itb.0 for ; Thu, 16 Feb 2017 13:09:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bsdimp-com.20150623.gappssmtp.com; s=20150623; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc; bh=j3LhGMQc1XsPRU8BYNQOOdspkFTmbJ0h6o0Z+rNYpgA=; b=E+ihDDtgMRt12SLB9b3vs8rHkBJ08PeASZREcb0zncpx0ee0fPL4wJWK7/s3F16ZWZ 8rc/f/KcB0T1SH2PHxgVqs1MS3In+uEJnbH79zLsnVdK7coovw15nECMavyc5LN8sqvC hopFoJxoL1xn9ob39UDZ/QdTaltmi8RNBVDoDbSg5Wz5r1xzCsK06l8F8Gwl4B2Js8p/ CBPxj5uTERVTo6bmwW4O18OA2sgTutAQX4qYU2JmjtKXyEi6nFkWkRv7hACfry7hDdGS QbKtNfQ9gI1NJX2fDf4aJQVlog+66pdGHwXENe/H1+vDLG9+fKZeg9R3fdM9foKBHH6t LlBQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to:cc; bh=j3LhGMQc1XsPRU8BYNQOOdspkFTmbJ0h6o0Z+rNYpgA=; b=eyG2vFw+2YRvVVPeGO1oIqcgadl1qPw3iOcrI48KTtLp30vlP+dh/08ZJYorQCaY6f X5/T/zRmwO7/Aydt4USUFjGqH+7zqIxkkazmDDmh4T2axwByax7bfAry1zR/SvLgt5m1 CbXWi7xBkdKNrUhJtyvRMYoWgK8HsmdmbuWWeBmKvcgdC8sqG1ljf3mSE276o7r+lVNG ero8m7PsXVDnWvQLNwwn0LDXM76ApWJl/MM8pw3IhZzFvshXVAgX4bRWisew5/4WBVWa yyDGsv6X3QvnoayQkohAul7vsxtsVymwdildjnXnno62wf6D9Iq54OJCSZuRVbpBKqiT 8yaA== X-Gm-Message-State: AMke39kEOe5wp0S3YjG4QZv6tjCe/XWq2H2veo+YfCWZ+uTFg4+W8QUapg6NuKS8N2rP7NkHtM5pxz1sdPsUDQ== X-Received: by 10.107.11.216 with SMTP id 85mr2974526iol.0.1487279369274; Thu, 16 Feb 2017 13:09:29 -0800 (PST) MIME-Version: 1.0 Sender: wlosh@bsdimp.com Received: by 10.79.145.217 with HTTP; Thu, 16 Feb 2017 13:09:28 -0800 (PST) X-Originating-IP: [50.253.99.174] In-Reply-To: <20170216174213.GA26791@fuz.su> References: <20170216174213.GA26791@fuz.su> From: Warner Losh Date: Thu, 16 Feb 2017 14:09:28 -0700 X-Google-Sender-Auth: 541KtIsLr2pqGkDmjTy-iu38zCw Message-ID: Subject: Re: lib32 support for ARM64 To: fuz@fuz.su Cc: "freebsd-arm@freebsd.org" Content-Type: text/plain; charset=UTF-8 X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Porting FreeBSD to ARM processors." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 16 Feb 2017 21:09:30 -0000 On Thu, Feb 16, 2017 at 10:42 AM, wrote: > Hello! > > I have recently started to use FreeBSD on my Raspberry Pi 3, when I > noticed that there is no lib32 support, i.e. you cannot run 32 bit ARM > binaries. As I am currently a student with a lot of time to kill during > the summer, I am thinking about implementing this. I would like to know: > > * what needs to be ported/adapted to get lib32 support working? > * has there been any existing work in this direction? > * is there interest in implementing this feature? > * if yes, would this feature be suitable for a gsoc project? > > I have no experience in working on the FreeBSD kernel except for a > one-line patch I wrote to get an LPT port card running. I have (for a > student) very good knowledge of programming in C. I know how to read and > write assembly code. I have a reasonable idea of how the FreeBSD kernel > is structured. There's two issues here: (1) building lib32 stuff. It isn't hard, but lots of grunt work given the differences between the tool chains for armv6 and arm64. (2) Running the 32-bit binaries (which we don't support). Past experience suggests it's on the order of a few days to a couple of weeks worth of work. But arm wasn't setup for 32/64 bit sharing so it is likely going to be on the longer end of that, if not a bit longer. Especially for a more junior person, so it would be a little small on the GSoC scale, but no worse than some other GSoCs that have been completed successfully. Warner