From owner-freebsd-arm@freebsd.org Tue Mar 13 07:49:17 2018 Return-Path: Delivered-To: freebsd-arm@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id ADD616438; Tue, 13 Mar 2018 07:49:17 +0000 (UTC) (envelope-from vishalgupta7972@gmail.com) Received: from mail-wr0-x234.google.com (mail-wr0-x234.google.com [IPv6:2a00:1450:400c:c0c::234]) (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 244666E583; Tue, 13 Mar 2018 07:49:17 +0000 (UTC) (envelope-from vishalgupta7972@gmail.com) Received: by mail-wr0-x234.google.com with SMTP id d10so7212593wrf.3; Tue, 13 Mar 2018 00:49:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=SEdTM3GCwQWEH7Z82VzE/bRA1qH55n86QttlXG92F3k=; b=tWqBYzo2V9LpBEQ/CQOZUQwxBJrTj73UpvSx2SN91SMCD93/UG+U5V5FWzTOKSZRFd Dd5HGomhQYPfyhuMmeaB1GDCZMeiquz2cVwl7YC9ENkyR+87j3iafqE23J+acZbE753L jdDP5GpWl1+1topmWMk49HBL/qphulTNfgoMK6AEyy6h1AORH0irMPaHWNvarkewdTgR +g0BcPsZ0F3pvs5Cw5re8OIE/v7SpJv75UQefd3ptu/NZTmbjU54xisnY8UOUtAii/4+ UW1yF+k4iQHjIcybmDUHce5D97GPRHMcUS4yg6wtjNePjgjB0zHgAEMJyQM8x71v3dkV i2EA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=SEdTM3GCwQWEH7Z82VzE/bRA1qH55n86QttlXG92F3k=; b=GVLcxR/I5nwHUuE4t8dxjn+0xtSJHJfL0BewqApqZd6u3HvbYSh2aQPoH8ej2DSzke xmTZqz1jT4zeeZFeJdpeGkjqK+VIIj64XURjiF38vWKL/h6K1JLxSx1HE0LjTe4h2j+f wE0aBC9miJBxgUYMyVzsob4C+YJS1WbdR9BT77QBQCm0pB0/7jYf0HqgfQOfQ8NUGQm/ d0iIdbwZX8U0ufLwiRnT2hQiJiMRiv1+BErR3Ke/53rCDKEwquWi7FD7lDP9rC2Qf/ap 4phlQwk+J229MxEMkAV64A9cUjigerVSVh2i+j452hUIFnbwARJcbAzeqLjHzEydG9dk SflA== X-Gm-Message-State: AElRT7HGnQBd1qE1nlzzdG1Xc3MbLtkUnlY3MaZJCUT9i2Q7cLH5QknE yspqyrEbU9667xnaF8X+GnryfBwJZhXR0cq9cyDNQ1p1 X-Google-Smtp-Source: AG47ELsA9aNgQiCA0cUicbIE9pqYwVYqSlB2oTAFypKtA2eqaOxcXr/GifuYkL4gjAelB3WX+besAwhx3QqGnfd+K6U= X-Received: by 10.223.179.84 with SMTP id k20mr8548681wrd.253.1520927355941; Tue, 13 Mar 2018 00:49:15 -0700 (PDT) MIME-Version: 1.0 Received: by 10.223.177.10 with HTTP; Tue, 13 Mar 2018 00:49:15 -0700 (PDT) In-Reply-To: References: From: Vishal Gupta Date: Tue, 13 Mar 2018 13:19:15 +0530 Message-ID: Subject: Re: GSOC 2018 ARM Cortex Processor To: Warner Losh Cc: Michael Zhilin , "freebsd-arm@freebsd.org" , "freebsd-embedded@freebsd.org" Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.25 X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: "Porting FreeBSD to ARM processors." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 13 Mar 2018 07:49:17 -0000 Thank you for the reply. Which new processor would you suggest between PowerPC, ARM, and MIPS which i can port during the summer period and will also be useful for the community. Vishal Gupta On Tue, Mar 13, 2018 at 11:52 AM, Warner Losh wrote: > There's not currently any other FreeBSD port that works on a system > without a MMU. The buffer cache assumes that we can fault in pages as > needed based on virtual address access. The TEXT sharing between programs > assumes we can map the same page into multiple processes. The shared > libraries we have assume something similar, and in some cases copy on write > on top of that (though that's no different from a HW perspective than these > first few cases). > > So, if you're willing to live without these features, or find some other > way to accomplish the same sorts of things, a cortex M/R port would be > tricky. Also, FreeBSD's kernel size may present some obstacles. We're > optimized for a rich memory environment, so we trade extra copies of code > to speed up execution of code, which matches the x86 market, as well as the > high-end of embedded quite well. > > If you are looking for a BSD to port to these processors, you might > consider looking at what www.retrobsd.org has done with their 2.11BSD > port to the MIPS processor in the PIC32 core with the MIPS M4K > architecture. It runs in as little as 128k of RAM, while FreeBSD these days > needs at least 128MB of RAM without careful tuning... > > Warner > > On Tue, Mar 13, 2018 at 12:07 AM, Michael Zhilin wrote: > >> Hi, >> >> Disclaimer: I'm neither ARM expect nor GSoC person. >> >> I may be wrong, but FreeBSD (or Linux, doesn't matter) requires MMU which >> is my tossing in Cortex M/R family of ARM processors. So it's technically >> difficult/impossible to port it on non-MMU processor. >> >> Added freebsd-arm@ for wide audience. >> >> Thank you! >> >> >> >> On Tue, Mar 13, 2018 at 1:12 PM, Vishal Gupta >> wrote: >> >> > Hi, >> > I am interested in working on the project to port FreeBSD to ARM Cortex >> M >> > or R series microprocessor. Some queries related to the project are :- >> > 1) What are the expected deliverable for the project. >> > 2) Where to put my draft proposal for review so that it can be improved. >> > >> > An early reply is awaited. >> > >> > Thanks and regards, >> > Vishal Gupta >> > _______________________________________________ >> > freebsd-embedded@freebsd.org mailing list >> > https://lists.freebsd.org/mailman/listinfo/freebsd-embedded >> > To unsubscribe, send any mail to "freebsd-embedded-unsubscribe@ >> freebsd.org >> > " >> > >> _______________________________________________ >> freebsd-embedded@freebsd.org mailing list >> https://lists.freebsd.org/mailman/listinfo/freebsd-embedded >> To unsubscribe, send any mail to "freebsd-embedded-unsubscribe@ >> freebsd.org" >> > >