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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3ADB2C64EC4 for ; Thu, 9 Mar 2023 21:52:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:References :In-Reply-To:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Ls0b0tQ4P4tBQIC9rPM485BWwooOu7BN4cm9lvNJ/QU=; b=wb1RuOv7Fq0hzl Jud7zHRbb7agM/inoPBrX/Zifxoi51nb1AK/F/7VHW+qD7etj1YBGrxL8EUnbhFpLUiwYrdPtXrgt bRKogVcDvQaexteYhKiN5BAsaNfzrWZWy/vH9pNtEqwigPy5BOCv07v8+op0kSMmzsdOeJADcYxv8 Z0rRV4KyC2KXCD2DoCJ+p9azThs9zXVF/KCP+y38U7v9QBS3h5Sn3eCrjfHzXus8fiXG9TWCduTa3 E15NIqynjMxVpIvf6uTG30cbKyEjshzwwXQNLF1i4KID3cj/XDLjvocN/721FN2LdpMVVLG6hxphv ykVf1qbzmNNJPBggP0Lg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1paOBr-00C533-CY; Thu, 09 Mar 2023 21:52:47 +0000 Received: from mail-pg1-x533.google.com ([2607:f8b0:4864:20::533]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1paOBo-00C528-F4 for linux-amlogic@lists.infradead.org; Thu, 09 Mar 2023 21:52:46 +0000 Received: by mail-pg1-x533.google.com with SMTP id bn17so1936597pgb.10 for ; Thu, 09 Mar 2023 13:52:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre-com.20210112.gappssmtp.com; s=20210112; t=1678398763; h=mime-version:message-id:date:references:in-reply-to:subject:cc:to :from:from:to:cc:subject:date:message-id:reply-to; bh=7nNOXbc+WHd5NABSbnw3+9ZkEtpuzcZoSp/LFLBByFA=; b=kfiM9MxY8vR15n0P+Q9WMzoNqzsyX/K61E9+p64hTU3fdlTpBiuHXT+QL4MCiMCwsZ /E0QrLsMb4Nut3KwGFTkPx82xRKD0Q6tg521BAsaxSjjgi0jp10LyKT4VcO3Ym5Nfp8j K99lBPkT863bgMXn81mWM52Y3HAXsnbgQXC/cQhkIUADsx8eC8BCkaezk1jyf3KnMbxe 5cey5kg6qiEDTnH7o5tkCNFGPtIcoIWnQj/s/71D62MPVHbi+/Yi6G5hwJTKjNnOycuD 8thUDBETxoMKd3r5r6WznnZXgw5w/5YPtXbhqUPh2vkm0LV7k6n6vMb+6MRMEVomuEWI oINw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678398763; h=mime-version:message-id:date:references:in-reply-to:subject:cc:to :from:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=7nNOXbc+WHd5NABSbnw3+9ZkEtpuzcZoSp/LFLBByFA=; b=JZlvZx0wYkSjjwl7Z1lNy2slewLtx/S4rcY2yB0xlzwgIRTFcw4vFZgCT68jPvd9QT yF7tfc8iOgFzftAwZ3+rR0YCammMReNZoRbmOwfrBkyy6hUfeseoAOAMyTJYS7lt3X/A rD2FNrrQOc6e5oGuky1SS57Y0dj0QivKabwHNHHZ4wt8U0NjRrriWSqgWhxlug1Qyi0m wBAMs0kuHq1yUBv1S/RvphePFNe3q6VzDSne+CTSikw5bEphQsmqVPPWgBLUQxwMKUUE CWGKSQCLPLum75cOwcgQ/Ujygaoedkv35+Cnp49rhveZQp4AT6iabNkCNy4mLOYH7J3n 3Egg== X-Gm-Message-State: AO0yUKX+2l7pXeqv+kuqQUdabcXn7FELywatIFIetMsoSriqfbjRN+NY CicxJcfMohjlrP7S5lJbpj3Zaw== X-Google-Smtp-Source: AK7set8Rgzrxi+ZGmbJxKNg4wUXFIFO8nTaU1MxHwhO6m2S5MjEM74yH44rUOwLH5ZFNysgyUIXqOg== X-Received: by 2002:aa7:980c:0:b0:5dc:2064:f7c4 with SMTP id e12-20020aa7980c000000b005dc2064f7c4mr22346879pfl.10.1678398762740; Thu, 09 Mar 2023 13:52:42 -0800 (PST) Received: from localhost (63-228-113-140.tukw.qwest.net. [63.228.113.140]) by smtp.gmail.com with ESMTPSA id 2-20020aa79142000000b00592543d7363sm69953pfi.1.2023.03.09.13.52.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Mar 2023 13:52:42 -0800 (PST) From: Kevin Hilman To: Dmitry Rokosov , Arnd Bergmann Cc: Neil Armstrong , Alexey Romanov , Rob Herring , krzysztof.kozlowski+dt@linaro.org, jbrunet@baylibre.com, martin.blumenstingl@googlemail.com, Linus Walleij , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org, kernel@sberdevices.ru Subject: Re: [PATCH v1 0/3] Meson A1 32-bit support In-Reply-To: <20230228084952.mgx3d3nw65yo5ebu@CAB-WSD-L081021> References: <20230222115020.55867-1-avromanov@sberdevices.ru> <8e5f9bfa-d612-cd43-d722-d04c40938c62@linaro.org> <20230227142809.kujmrraf3pcdhqyn@CAB-WSD-L081021> <20230227155100.hhl4yvkyfqfyoa6h@CAB-WSD-L081021> <33b58877-5167-c453-e686-1d10cdca66c0@linaro.org> <20230227165049.4y7jx5nnnlibe6kg@CAB-WSD-L081021> <7d29f3fd-b8c8-4687-b6a0-b8956dd39f0b@app.fastmail.com> <20230228084952.mgx3d3nw65yo5ebu@CAB-WSD-L081021> Date: Thu, 09 Mar 2023 13:52:41 -0800 Message-ID: <7hedpxwq1i.fsf@baylibre.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230309_135244_528581_F5169042 X-CRM114-Status: GOOD ( 23.52 ) X-BeenThere: linux-amlogic@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-amlogic" Errors-To: linux-amlogic-bounces+linux-amlogic=archiver.kernel.org@lists.infradead.org Dmitry Rokosov writes: > On Mon, Feb 27, 2023 at 07:19:38PM +0100, Arnd Bergmann wrote: >> On Mon, Feb 27, 2023, at 17:50, Dmitry Rokosov wrote: >> > On Mon, Feb 27, 2023 at 05:38:49PM +0100, Neil Armstrong wrote: >> >> On 27/02/2023 17:15, Arnd Bergmann wrote: >> >> > On Mon, Feb 27, 2023, at 16:51, Dmitry Rokosov wrote: >> >> > >> >> > Most of these don't apply in userspace, so the incentive to >> >> > run smaller 32-bit userland on systems with less than 1GB of >> >> > RAM usually outweighs the benefits of 64-bit userspace. >> >> >> >> Thanks for the details! >> > >> > Looks like Thomas has already prepared a basic patch series for buildroot, >> > but maintainers declined it. >> > >> > https://lore.kernel.org/all/20220730194331.GA2515056@scaer/ >> >> I see. I know very little about buildroot, but it sounds like >> there are other ways of doing the same thing here. In general, >> this is pretty much an Arm specific problem. While you clearly >> want compat mode for small userland on any architecture but don't >> want 32-bit kernels, arm is the only one that has a different >> kernel "ARCH=" value and needs a separate gcc toolchain. >> >> If the problem is only the toolchain, an easy way out may >> be to use clang instead of gcc as your compiler, as a single >> clang binary can target both 32-bit userland and 64-bit kernel >> on all supported architectures. > > Agreed with you. We will try different local approaches to support > compat build configurations. For now, prebuilt toolchain (buildroot make > sdk goal) is best way from my point of view. Anyway, we will try to > solve this problem in the our sandbox and stay on the 64-bit kernel. > Thank you for all the helpful details you shared, appreciate it! Just to clarify one thing... More specifically, this is a buildroot *build system* problem. If you build the kernel separately from the rootfs, it works fine. I use 32-bit buildroot (and debian) rootfs images all the time on Amlogic SoCs with 64-bit kernels and it works fine. Kevin _______________________________________________ linux-amlogic mailing list linux-amlogic@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-amlogic 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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8E509C64EC4 for ; Thu, 9 Mar 2023 21:53:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:References :In-Reply-To:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Bvudu4Rc4SYv/xp25jm+NeoUhlPh/gK0a9mmtx6J+zU=; b=qptF0j6w61GY/j vt+R+ykIr4e9NoeAHlbOyoxOywCajFcG5CfXf0nbFz1Ee0AwmDr+JjvnAk6ef5+qA6VHOc9lySe+b wQjhjJz0+aNMSfgSMGPQ8y1hC0sZtGPXR2KpkRziu0R+00cc7183lWHV/pzbArIZ8MJWc79JxlFui XoIRDoYhXPe+adWt/7ktxKqAk01khY+Dc0vM+oIa7gpTgqmvzOfdO0bIsB+a28BXf4wyPpK2V3F2A T6bspvNp67/e02QZJsWXhPfyXTwM1cCdR+OGCtIEWDPXNKWL/PY5IsuX1In45kcP9aGbym6qkk+q1 ZkXx5kDhAQm621bK16Ww==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1paOBr-00C539-Vs; Thu, 09 Mar 2023 21:52:48 +0000 Received: from mail-pg1-x532.google.com ([2607:f8b0:4864:20::532]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1paOBo-00C527-Jn for linux-arm-kernel@lists.infradead.org; Thu, 09 Mar 2023 21:52:46 +0000 Received: by mail-pg1-x532.google.com with SMTP id d6so1958910pgu.2 for ; Thu, 09 Mar 2023 13:52:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre-com.20210112.gappssmtp.com; s=20210112; t=1678398763; h=mime-version:message-id:date:references:in-reply-to:subject:cc:to :from:from:to:cc:subject:date:message-id:reply-to; bh=7nNOXbc+WHd5NABSbnw3+9ZkEtpuzcZoSp/LFLBByFA=; b=kfiM9MxY8vR15n0P+Q9WMzoNqzsyX/K61E9+p64hTU3fdlTpBiuHXT+QL4MCiMCwsZ /E0QrLsMb4Nut3KwGFTkPx82xRKD0Q6tg521BAsaxSjjgi0jp10LyKT4VcO3Ym5Nfp8j K99lBPkT863bgMXn81mWM52Y3HAXsnbgQXC/cQhkIUADsx8eC8BCkaezk1jyf3KnMbxe 5cey5kg6qiEDTnH7o5tkCNFGPtIcoIWnQj/s/71D62MPVHbi+/Yi6G5hwJTKjNnOycuD 8thUDBETxoMKd3r5r6WznnZXgw5w/5YPtXbhqUPh2vkm0LV7k6n6vMb+6MRMEVomuEWI oINw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678398763; h=mime-version:message-id:date:references:in-reply-to:subject:cc:to :from:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=7nNOXbc+WHd5NABSbnw3+9ZkEtpuzcZoSp/LFLBByFA=; b=oVBuwDekiAe71E3JWS9laRujavAJn8/FAo+0yAUCtHv0KM1NPmkODl9Tc2nsDhrli7 hCy3aglDqTWT9oWW/pwyg7Jz3Gs7O22QwuS+vicOsdXdDueKt1RdhZVam9/hioBXFgRk XsCBjLFe7Btmv/7gh7+UT6bYIJbepn6Al/GVoswzXGALUppfXyKZ7gb+jG2fi4bkJYgu kYClAwSM+K3ZawkzvO3Qod+jPfRsudXHsTPICd3ecEbwnp5HtMBGV3UpZdgdgmQFL2yo UGtQ22Z03GuhmMfDbAqK89VIZq/62zcmG8nZux8a3M9EvRh2Ri8NZibsSf7C77IB4NyR bG3A== X-Gm-Message-State: AO0yUKUspRRdoPeX8EhVRBsAi5Mn6kahZ2V9VFvE2CE9YelZtS+5ifXA h0/kb2pxhA91WJZE2e9zh/vDmQ== X-Google-Smtp-Source: AK7set8Rgzrxi+ZGmbJxKNg4wUXFIFO8nTaU1MxHwhO6m2S5MjEM74yH44rUOwLH5ZFNysgyUIXqOg== X-Received: by 2002:aa7:980c:0:b0:5dc:2064:f7c4 with SMTP id e12-20020aa7980c000000b005dc2064f7c4mr22346879pfl.10.1678398762740; Thu, 09 Mar 2023 13:52:42 -0800 (PST) Received: from localhost (63-228-113-140.tukw.qwest.net. [63.228.113.140]) by smtp.gmail.com with ESMTPSA id 2-20020aa79142000000b00592543d7363sm69953pfi.1.2023.03.09.13.52.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Mar 2023 13:52:42 -0800 (PST) From: Kevin Hilman To: Dmitry Rokosov , Arnd Bergmann Cc: Neil Armstrong , Alexey Romanov , Rob Herring , krzysztof.kozlowski+dt@linaro.org, jbrunet@baylibre.com, martin.blumenstingl@googlemail.com, Linus Walleij , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org, kernel@sberdevices.ru Subject: Re: [PATCH v1 0/3] Meson A1 32-bit support In-Reply-To: <20230228084952.mgx3d3nw65yo5ebu@CAB-WSD-L081021> References: <20230222115020.55867-1-avromanov@sberdevices.ru> <8e5f9bfa-d612-cd43-d722-d04c40938c62@linaro.org> <20230227142809.kujmrraf3pcdhqyn@CAB-WSD-L081021> <20230227155100.hhl4yvkyfqfyoa6h@CAB-WSD-L081021> <33b58877-5167-c453-e686-1d10cdca66c0@linaro.org> <20230227165049.4y7jx5nnnlibe6kg@CAB-WSD-L081021> <7d29f3fd-b8c8-4687-b6a0-b8956dd39f0b@app.fastmail.com> <20230228084952.mgx3d3nw65yo5ebu@CAB-WSD-L081021> Date: Thu, 09 Mar 2023 13:52:41 -0800 Message-ID: <7hedpxwq1i.fsf@baylibre.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230309_135244_659244_E2520A1F X-CRM114-Status: GOOD ( 24.99 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Dmitry Rokosov writes: > On Mon, Feb 27, 2023 at 07:19:38PM +0100, Arnd Bergmann wrote: >> On Mon, Feb 27, 2023, at 17:50, Dmitry Rokosov wrote: >> > On Mon, Feb 27, 2023 at 05:38:49PM +0100, Neil Armstrong wrote: >> >> On 27/02/2023 17:15, Arnd Bergmann wrote: >> >> > On Mon, Feb 27, 2023, at 16:51, Dmitry Rokosov wrote: >> >> > >> >> > Most of these don't apply in userspace, so the incentive to >> >> > run smaller 32-bit userland on systems with less than 1GB of >> >> > RAM usually outweighs the benefits of 64-bit userspace. >> >> >> >> Thanks for the details! >> > >> > Looks like Thomas has already prepared a basic patch series for buildroot, >> > but maintainers declined it. >> > >> > https://lore.kernel.org/all/20220730194331.GA2515056@scaer/ >> >> I see. I know very little about buildroot, but it sounds like >> there are other ways of doing the same thing here. In general, >> this is pretty much an Arm specific problem. While you clearly >> want compat mode for small userland on any architecture but don't >> want 32-bit kernels, arm is the only one that has a different >> kernel "ARCH=" value and needs a separate gcc toolchain. >> >> If the problem is only the toolchain, an easy way out may >> be to use clang instead of gcc as your compiler, as a single >> clang binary can target both 32-bit userland and 64-bit kernel >> on all supported architectures. > > Agreed with you. We will try different local approaches to support > compat build configurations. For now, prebuilt toolchain (buildroot make > sdk goal) is best way from my point of view. Anyway, we will try to > solve this problem in the our sandbox and stay on the 64-bit kernel. > Thank you for all the helpful details you shared, appreciate it! Just to clarify one thing... More specifically, this is a buildroot *build system* problem. If you build the kernel separately from the rootfs, it works fine. I use 32-bit buildroot (and debian) rootfs images all the time on Amlogic SoCs with 64-bit kernels and it works fine. Kevin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel 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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AA404C64EC4 for ; Thu, 9 Mar 2023 21:52:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230171AbjCIVwt (ORCPT ); Thu, 9 Mar 2023 16:52:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44506 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230028AbjCIVws (ORCPT ); Thu, 9 Mar 2023 16:52:48 -0500 Received: from mail-pg1-x52c.google.com (mail-pg1-x52c.google.com [IPv6:2607:f8b0:4864:20::52c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6082B10287A for ; Thu, 9 Mar 2023 13:52:43 -0800 (PST) Received: by mail-pg1-x52c.google.com with SMTP id 16so1927273pge.11 for ; Thu, 09 Mar 2023 13:52:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre-com.20210112.gappssmtp.com; s=20210112; t=1678398763; h=mime-version:message-id:date:references:in-reply-to:subject:cc:to :from:from:to:cc:subject:date:message-id:reply-to; bh=7nNOXbc+WHd5NABSbnw3+9ZkEtpuzcZoSp/LFLBByFA=; b=kfiM9MxY8vR15n0P+Q9WMzoNqzsyX/K61E9+p64hTU3fdlTpBiuHXT+QL4MCiMCwsZ /E0QrLsMb4Nut3KwGFTkPx82xRKD0Q6tg521BAsaxSjjgi0jp10LyKT4VcO3Ym5Nfp8j K99lBPkT863bgMXn81mWM52Y3HAXsnbgQXC/cQhkIUADsx8eC8BCkaezk1jyf3KnMbxe 5cey5kg6qiEDTnH7o5tkCNFGPtIcoIWnQj/s/71D62MPVHbi+/Yi6G5hwJTKjNnOycuD 8thUDBETxoMKd3r5r6WznnZXgw5w/5YPtXbhqUPh2vkm0LV7k6n6vMb+6MRMEVomuEWI oINw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678398763; h=mime-version:message-id:date:references:in-reply-to:subject:cc:to :from:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=7nNOXbc+WHd5NABSbnw3+9ZkEtpuzcZoSp/LFLBByFA=; b=fkJtZ0YHiRDW8LsNml1Ce/ErHhWxx5Gr3t0Rxdt0iwwOSH+EKtxkslpcxapCXRW6WU mahqL7YYcEO9vImp/WpOSGBAivuiDZk5ZOoPUOhlbSWn6O6IiVP9kYaATjJjQG4JKIaa TWYEViVc9KOWMVf0Qrc6mmHIPUA50Ps5Uh/jmFrXBfOjWOvlOAGGTYL8aquRRE0/FxMD LCgEResLKfa9DglhF1z+woaLfaOX/1swgkj27pR2Vtkz6/hE8s0Y+LKAdsS5z2yu4X5m T+zfprg566SmBn2dgGjjtM4hslAdQTGi/i7V4IKrD5ZDbzJhO+L503L3il2EG3oyGkIH bBYA== X-Gm-Message-State: AO0yUKUd4QCBuDkzRYXqEAIHPz+cpfOWOCARk52FYMd0afL9OzmR00Bo +78kdmbgCJV2qa6kdICaN4InBA== X-Google-Smtp-Source: AK7set8Rgzrxi+ZGmbJxKNg4wUXFIFO8nTaU1MxHwhO6m2S5MjEM74yH44rUOwLH5ZFNysgyUIXqOg== X-Received: by 2002:aa7:980c:0:b0:5dc:2064:f7c4 with SMTP id e12-20020aa7980c000000b005dc2064f7c4mr22346879pfl.10.1678398762740; Thu, 09 Mar 2023 13:52:42 -0800 (PST) Received: from localhost (63-228-113-140.tukw.qwest.net. [63.228.113.140]) by smtp.gmail.com with ESMTPSA id 2-20020aa79142000000b00592543d7363sm69953pfi.1.2023.03.09.13.52.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Mar 2023 13:52:42 -0800 (PST) From: Kevin Hilman To: Dmitry Rokosov , Arnd Bergmann Cc: Neil Armstrong , Alexey Romanov , Rob Herring , krzysztof.kozlowski+dt@linaro.org, jbrunet@baylibre.com, martin.blumenstingl@googlemail.com, Linus Walleij , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org, kernel@sberdevices.ru Subject: Re: [PATCH v1 0/3] Meson A1 32-bit support In-Reply-To: <20230228084952.mgx3d3nw65yo5ebu@CAB-WSD-L081021> References: <20230222115020.55867-1-avromanov@sberdevices.ru> <8e5f9bfa-d612-cd43-d722-d04c40938c62@linaro.org> <20230227142809.kujmrraf3pcdhqyn@CAB-WSD-L081021> <20230227155100.hhl4yvkyfqfyoa6h@CAB-WSD-L081021> <33b58877-5167-c453-e686-1d10cdca66c0@linaro.org> <20230227165049.4y7jx5nnnlibe6kg@CAB-WSD-L081021> <7d29f3fd-b8c8-4687-b6a0-b8956dd39f0b@app.fastmail.com> <20230228084952.mgx3d3nw65yo5ebu@CAB-WSD-L081021> Date: Thu, 09 Mar 2023 13:52:41 -0800 Message-ID: <7hedpxwq1i.fsf@baylibre.com> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Dmitry Rokosov writes: > On Mon, Feb 27, 2023 at 07:19:38PM +0100, Arnd Bergmann wrote: >> On Mon, Feb 27, 2023, at 17:50, Dmitry Rokosov wrote: >> > On Mon, Feb 27, 2023 at 05:38:49PM +0100, Neil Armstrong wrote: >> >> On 27/02/2023 17:15, Arnd Bergmann wrote: >> >> > On Mon, Feb 27, 2023, at 16:51, Dmitry Rokosov wrote: >> >> > >> >> > Most of these don't apply in userspace, so the incentive to >> >> > run smaller 32-bit userland on systems with less than 1GB of >> >> > RAM usually outweighs the benefits of 64-bit userspace. >> >> >> >> Thanks for the details! >> > >> > Looks like Thomas has already prepared a basic patch series for buildroot, >> > but maintainers declined it. >> > >> > https://lore.kernel.org/all/20220730194331.GA2515056@scaer/ >> >> I see. I know very little about buildroot, but it sounds like >> there are other ways of doing the same thing here. In general, >> this is pretty much an Arm specific problem. While you clearly >> want compat mode for small userland on any architecture but don't >> want 32-bit kernels, arm is the only one that has a different >> kernel "ARCH=" value and needs a separate gcc toolchain. >> >> If the problem is only the toolchain, an easy way out may >> be to use clang instead of gcc as your compiler, as a single >> clang binary can target both 32-bit userland and 64-bit kernel >> on all supported architectures. > > Agreed with you. We will try different local approaches to support > compat build configurations. For now, prebuilt toolchain (buildroot make > sdk goal) is best way from my point of view. Anyway, we will try to > solve this problem in the our sandbox and stay on the 64-bit kernel. > Thank you for all the helpful details you shared, appreciate it! Just to clarify one thing... More specifically, this is a buildroot *build system* problem. If you build the kernel separately from the rootfs, it works fine. I use 32-bit buildroot (and debian) rootfs images all the time on Amlogic SoCs with 64-bit kernels and it works fine. Kevin