From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lj1-x231.google.com (mail-lj1-x231.google.com [IPv6:2a00:1450:4864:20::231]) by sourceware.org (Postfix) with ESMTPS id 85E513858C66 for ; Sat, 23 Sep 2023 15:57:45 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 85E513858C66 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=systemhalted.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=systemhalted.org Received: by mail-lj1-x231.google.com with SMTP id 38308e7fff4ca-2bb9a063f26so59794241fa.2 for ; Sat, 23 Sep 2023 08:57:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=systemhalted.org; s=google; t=1695484664; x=1696089464; darn=sourceware.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=Vb7WxFJDx3Q3JA3tGZRsuiJXx6Z9COrPNyc/YBhc0/Y=; b=CeKOJ7+uabYImE7aR4Sai5EoIqks6nFaCqbA4LaeZC4K58g3dH9Eoq64jTi7DVXYye iJ1DXDlXllOZsPfJnwk87Po7gposn8JXLB/texxiCBzCoPQkoLp7lkp6UbY256eXNDN3 s0in+VwgIXHo5IxO2UC5xlbtqkQgEo8b6ApKo= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1695484664; x=1696089464; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Vb7WxFJDx3Q3JA3tGZRsuiJXx6Z9COrPNyc/YBhc0/Y=; b=DJTQxebPco9485ZHyLPDmQa5sm11rjoAbUg7dkoxBuY8YjjBLT7I5Ow+3x9TQLvVF/ phYFN1gcBdoZc2lPnop2HN/A57t5DELiJdfUqbsNvq7olTu1vk2wCp4Dqew42+ge7ugE kUKuQ6x9ThTJ+7CkWLIbywYq7+Frx5vqytbW4p1m1JeLgWqeSgvfEQeZldm3cj9aO9v0 iaiNET0FacdhJNvu0+KAj+Vk7o2cSX9F/4sRGirt77ixHj8N1ZqTUbN52VjFaKj2kz+z MZGmnvwBMRuBv5y+9/9FAIoTf/RwxgEMwKqrfBBTbWKMaXWEBBWQhHLVkLJ98XV8ArP8 v1Yg== X-Gm-Message-State: AOJu0YwpVm5c6nt7ayesV13UGg2IqxStK4fP4b8X3vSxeP1hf37+FXJ+ pZYNZP5hEC3Ugi94QWhKTWMM9djI87hTmZfx19owLg== X-Google-Smtp-Source: AGHT+IEYcRgv0sfSnOmqcVz6zx85Wg6sYc7a43HA+QCFAZhtsHE7xnOGNy0CKIry3hQSWDG4uCRzcPk4RmeWiVBdt6M= X-Received: by 2002:a2e:7010:0:b0:2bb:985f:8479 with SMTP id l16-20020a2e7010000000b002bb985f8479mr1792719ljc.48.1695484663676; Sat, 23 Sep 2023 08:57:43 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: "Carlos O'Donell" Date: Sat, 23 Sep 2023 11:57:32 -0400 Message-ID: Subject: Re: Does glibc require a MMU? To: Chris Packham Cc: Chris Packham via Libc-help Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=1.2 required=5.0 tests=BAYES_00,DKIM_INVALID,DKIM_SIGNED,KAM_DMARC_STATUS,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=no autolearn_force=no version=3.4.6 X-Spam-Level: * X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On Fri, Sep 22, 2023 at 8:10=E2=80=AFPM Chris Packham via Libc-help wrote: > I'm looking at tidying some things up in crosstool-ng. Currently we > don't allow selecting GLIBC if the architecture doesn't support a MMU. > A user pointed out that that means that we can't build a > m68k-linux-gnu toolchain but per the GLIBC README that configuration > is supported. We have 3 valid and supported ~m68k ABIs: https://sourceware.org/glibc/wiki/ABIList#m68k The supported ColdFire targets have an MMU. > I think the specific case of m68k is a bit subtle because there are > MMU-less variants. So while the architecture clearly allows for a MMU > not all variants of the CPU will have one. I probably will set the > flag to say m68k supports a MMU but I'm wondering if more generally I > should just allow glibc to be selected regardless of MMU support. You need an MMU to support running glibc, the implementation of the dynamic loader, and certain functions and algorithms depend on having an MMU to do certain operations with memory mappings. How you choose to express this in cross-toolng is up to you, and whatever serves your users best :-) Cheers, Carlos.