From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CAD5BC4338F for ; Mon, 9 Aug 2021 14:11:52 +0000 (UTC) Received: from phobos.denx.de (phobos.denx.de [85.214.62.61]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8399760EC0 for ; Mon, 9 Aug 2021 14:11:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 8399760EC0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=denx.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.denx.de Received: from h2850616.stratoserver.net (localhost [IPv6:::1]) by phobos.denx.de (Postfix) with ESMTP id C029B80394; Mon, 9 Aug 2021 16:11:48 +0200 (CEST) Authentication-Results: phobos.denx.de; dmarc=none (p=none dis=none) header.from=denx.de Authentication-Results: phobos.denx.de; spf=pass smtp.mailfrom=u-boot-bounces@lists.denx.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1628518309; bh=BktDkMAzqy3KCN2irwK7Kr0QzVWZccIr0ib7m0GnY9M=; h=To:cc:From:Subject:In-reply-to:References:Date:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=IAWBj2q7P5jhgpE8TXpu5OZa+c/G+C+VtEPvqrU9vE1tfpmOMy0XA6HtjB14dhveu 9xLeK0bvcxr4qQUNhPKZMRa24aIUX5CmUcveq6Wd4NfmUC2mfzLO5IBVLoiSlsvz+z iV0JyGNqEpwaViXWrdjDyvMFpqNfAPW1zJ2UDNzgz9B307LJdgZdioMA/D/695ODRd /+8pw5tpNFRTL20JwFtu7CF38Sua9H4pvPalIpW1N+QBEBG3Q0Hw7b+7531zLDMklf P8Yuioa3mTQ3TPPue+VG2MD0/EpR2tvbgideHPlJSSmVXxxD9tmkr8lFzNA4JJVKk9 jPcSMDcDVK7mA== Received: from janitor.denx.de (unknown [62.91.23.180]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: noc@denx.de) by phobos.denx.de (Postfix) with ESMTPSA id 573EB81D6C for ; Mon, 9 Aug 2021 16:11:46 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1628518306; bh=BktDkMAzqy3KCN2irwK7Kr0QzVWZccIr0ib7m0GnY9M=; h=To:cc:From:Subject:In-reply-to:References:Date:From; b=z5CZ1AInJ1Bs8UEm50Tl+qqaNI6cH6ze4a8+EYoU3+TF0sFQAYZmmPtBcHAwt8ESw jEaaKcFoZtW7rtgLBLEJ/gAKdZltYykQzVaxNl3uggeNdsu+81GQpUQDwmH0y5at+e bHTGX2nEWokE9D//n626fPFdgQPjRrkxyIhXe8FdvvFwZYP3WO12gYIKJwPMkc07OB msYvJLzKutMh5AnQWszddFZ1irauW70hgiPpPrKYaiP+9fGrMgPkxy4rqtoonwZwf+ XHTy/UFf5X3y//x+FWI/dxjp8hcEJ0/JyVqBeBYaAy3OZyvwrS5XNFFnp/dM4h8gaV 04rwEz6AfN+QQ== Received: by janitor.denx.de (Postfix, from userid 108) id 09C5FA01DF; Mon, 9 Aug 2021 16:11:46 +0200 (CEST) Received: from gemini.denx.de (gemini.denx.de [10.4.0.2]) by janitor.denx.de (Postfix) with ESMTPS id EDE48A005A; Mon, 9 Aug 2021 16:11:36 +0200 (CEST) Received: from gemini.denx.de (localhost [IPv6:::1]) by gemini.denx.de (Postfix) with ESMTP id 8E3D61E2304; Mon, 9 Aug 2021 16:11:36 +0200 (CEST) To: Tom Rini cc: Ye Li , "marex@denx.de" , "swarren@nvidia.com" , "hai.pham.ud@renesas.com" , "u-boot@lists.denx.de" , "simon.k.r.goldschmidt@gmail.com" , "lokeshvutla@ti.com" , "jan.kiszka@siemens.com" From: Wolfgang Denk Subject: Re: [EXT] Re: [PATCH] Revert "arm: bootm: Disable LMB reservation for command line and board info on arm64" MIME-Version: 1.0 Content-type: text/plain; charset=UTF-8 Content-transfer-encoding: 8bit In-reply-to: <20210809131640.GN858@bill-the-cat> References: <20210802212759.GD9379@bill-the-cat> <20210803215144.GW9379@bill-the-cat> <015eed03-b945-8757-e994-17d17de45546@denx.de> <20210806164917.GB858@bill-the-cat> <4aff44db-6a83-bcce-a405-1662187983b2@denx.de> <20210808140010.GH858@bill-the-cat> <03720507-5ea4-0fb9-0549-37df3128be2b@denx.de> <20210808145457.GI858@bill-the-cat> <9dbf9adb-7f6b-4b3c-859a-9a0024c69917@denx.de> <1628494486.86799.17.camel@nxp.com> <20210809131640.GN858@bill-the-cat> Comments: In-reply-to Tom Rini message dated "Mon, 09 Aug 2021 09:16:40 -0400." Date: Mon, 09 Aug 2021 16:11:36 +0200 Message-ID: <433360.1628518296@gemini.denx.de> X-BeenThere: u-boot@lists.denx.de X-Mailman-Version: 2.1.34 Precedence: list List-Id: U-Boot discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: u-boot-bounces@lists.denx.de Sender: "U-Boot" X-Virus-Scanned: clamav-milter 0.103.2 at phobos.denx.de X-Virus-Status: Clean Dear Tom, In message <20210809131640.GN858@bill-the-cat> you wrote: > > Thanks for explaining. It sounds like > arch/arm/mach-imx/imx8m/soc.c::the=A0ft_system_setup() needs a comment > that it uses a lot of stack, due to how complex it is, and that I think this is the wrong approach. It sounds as if we were discouragin the use of the stack for dynamic buffers etc. We should not do that. Instead, we should make sure that the stack starts below any reserved memory locations, and is free to grow downward as long as there is still memory available. If U-Boot was an OS, we would probably think about implementing a more complex memory management utilizing the MMU, but in a boot loader this is clearly overkill. But please, just let the stack grow as it wants. There may be completely legal use cases with unpredictable stack requirements. Think about recursive shell scripts, for example... Best regards, Wolfgang Denk -- DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de "Remember, Information is not knowledge; Knowledge is not Wisdom; Wisdom is not truth; Truth is not beauty; Beauty is not love; Love is not music; Music is the best." - Frank Zappa