From owner-freebsd-embedded@freebsd.org Tue Mar 8 21:32:34 2016 Return-Path: Delivered-To: freebsd-embedded@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 67336A13208 for ; Tue, 8 Mar 2016 21:32:34 +0000 (UTC) (envelope-from brad2000@gmail.com) Received: from mail-vk0-x22c.google.com (mail-vk0-x22c.google.com [IPv6:2607:f8b0:400c:c05::22c]) (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 20FC6686 for ; Tue, 8 Mar 2016 21:32:34 +0000 (UTC) (envelope-from brad2000@gmail.com) Received: by mail-vk0-x22c.google.com with SMTP id k1so33568578vkb.0 for ; Tue, 08 Mar 2016 13:32:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc; bh=fxKUIQ3kBlK/EdW32AauteYdbjws9J6qTwrR8Up3Ays=; b=Bc9XS2RnEG21OQAXIBBsF/I8VgsOTLD9QreiXb5oleRY3hGTVxclZV956MXunW26be LNsTTMoZ5WV4QvHsGijIKIzmDRKSvMfA25piJ5y+EKKR74PJxHoQlJh2KOcG0gxOb6wS QM7rQPC0YRUTiOnZ2or+OM7l6VYwzrUVJ9DTxrI0DyJy0lX08kF1GSpdKWabbU41d02s Du0i/wzC938BWUvXuxeqlNkYy8WGNuL9diQZvKAetdoCuQiQipkzEYqeOpMJxWgpgdBa wV/Gby+0Yw3WV5pFqMSM0hbQkw9h5/jWmfGQzdbJYOePZHxCZLH/YM7JtCOfeTtNMBBt GGmQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:sender:in-reply-to:references:date :message-id:subject:from:to:cc; bh=fxKUIQ3kBlK/EdW32AauteYdbjws9J6qTwrR8Up3Ays=; b=dUCelqZLuy6PLBq3MxpYE86bcmqbFmMwNM2i9BSPNWWNP6owciwOI2A3QAsMn0WxeE 0lG4ZKosg8Lo9bSjPLPySTTKrGIkBIuWN3ZWcORUv77zNLvynJtpqTtvrb/VER32ttPA 8q9+m4BhCyWDSR0R8SjJQxsQNnncA1YmEFg/VBT8mhbnQwLtMcOKSadR/KoJoo92RFe6 fy7vZNRWR08WwSOaL82vZUxAD0naardtVLk3UqNeX06IHRsUoICf1kjGh9QED7LWTBrU n9y180Fbba2B3OvK7taeKL4iJSKImeMJj0fhgxeZwTBThtpXb1XzfgDidjIyIsgHOlZB Jk7w== X-Gm-Message-State: AD7BkJIqchTPa+/zjVXLR27x3qUTb+NSJ8SsX0WmLA1b7/4GOdbjzxOx5ac6oACraCvT19kVkSb1w/HA9mebgw== MIME-Version: 1.0 X-Received: by 10.31.128.15 with SMTP id b15mr28110168vkd.128.1457472753165; Tue, 08 Mar 2016 13:32:33 -0800 (PST) Sender: brad2000@gmail.com Received: by 10.31.163.18 with HTTP; Tue, 8 Mar 2016 13:32:33 -0800 (PST) In-Reply-To: References: Date: Tue, 8 Mar 2016 14:32:33 -0700 X-Google-Sender-Auth: yg2Vqafdd8_g-THkea3LMkelDFI Message-ID: Subject: Re: ? about kernel size.. From: Brad Walker To: Warner Losh Cc: "freebsd-embedded@freebsd.org" Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.21 X-BeenThere: freebsd-embedded@freebsd.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: Dedicated and Embedded Systems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 08 Mar 2016 21:32:34 -0000 On Tue, Mar 8, 2016 at 11:42 AM, Warner Losh wrote: > > > On Tue, Mar 8, 2016 at 10:42 AM, Brad Walker wrote: > >> I'm looking at working on a new project that will use the FreeBSD kernel. >> I >> would attempt to embed the kernel on a very small NXP Kinetis chip. I've >> previously done this using a Linux kernel but also had DDR memory attached >> to the chip. This project would not have a DDR chip attached. >> >> So a couple of questions. 1 - What is the smallest size I could configure >> the FreeBSD kernel out of the box? Could I get the size to be less than >> 10MB, 5MB, 2MB, or etc.? >> > > I've managed to get this down to about 2MB or a bit smaller. Compressed > this can be a little smaller. It takes a fair amount of work, but it can be > done. > > That's great.. Was this out of the box tuning? > > I did a little bit of research on the PicoBSD and NanoBSD but that still >> seem to be targeted to a little bit bigger chip than I have available. >> > > How big a chip do you have? NanoBSD currently needs at least > 64MB (and ideally 128MB) of storage. PicoBSD can be a bit smaller. > I have 2MB on-chip flash and 512KB of SRAM. There is an external flash that will be attached. What I'm currently thinking is that I would like to boot into BusyBox verses multi-user.. One question that I'm curious about. All the work that I do on this, or you've done in the past, how does it get integrated into the mainline build. -brad w.