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 smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (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 787B1C43334 for ; Sat, 23 Jul 2022 13:25:13 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id 0E63484645; Sat, 23 Jul 2022 13:25:13 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp1.osuosl.org 0E63484645 X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id hhvQE4h7el78; Sat, 23 Jul 2022 13:25:12 +0000 (UTC) Received: from ash.osuosl.org (ash.osuosl.org [140.211.166.34]) by smtp1.osuosl.org (Postfix) with ESMTP id 0CF4B84123; Sat, 23 Jul 2022 13:25:11 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp1.osuosl.org 0CF4B84123 Received: from smtp4.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by ash.osuosl.org (Postfix) with ESMTP id 039181BF31A for ; Sat, 23 Jul 2022 13:25:09 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id DC5F141716 for ; Sat, 23 Jul 2022 13:25:08 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp4.osuosl.org DC5F141716 X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id OMx1v3azeuRY for ; Sat, 23 Jul 2022 13:25:07 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 DKIM-Filter: OpenDKIM Filter v2.11.0 smtp4.osuosl.org ED2234170A Received: from relay3-d.mail.gandi.net (relay3-d.mail.gandi.net [217.70.183.195]) by smtp4.osuosl.org (Postfix) with ESMTPS id ED2234170A for ; Sat, 23 Jul 2022 13:25:06 +0000 (UTC) Received: (Authenticated sender: thomas.petazzoni@bootlin.com) by mail.gandi.net (Postfix) with ESMTPSA id 420E660004; Sat, 23 Jul 2022 13:25:04 +0000 (UTC) Date: Sat, 23 Jul 2022 15:25:03 +0200 To: Romain Naour Message-ID: <20220723152503.5e2417cb@windsurf> In-Reply-To: <5fd9249b-0815-0b8a-9cb5-a301d04ec5d3@smile.fr> References: <20220529131811.481017-1-romain.naour@gmail.com> <20220723143921.1e89b49f@windsurf> <5fd9249b-0815-0b8a-9cb5-a301d04ec5d3@smile.fr> Organization: Bootlin X-Mailer: Claws Mail 4.1.0 (GTK 3.24.34; x86_64-redhat-linux-gnu) MIME-Version: 1.0 X-Mailman-Original-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1658582705; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+CHKRvDukY1QYmNzqJCSUr4hAsV67nOzUAuvN491sZE=; b=O/XEyrCr/zG/8E+luZXF8wm5nvhw1r8ORyee1KXgz6PljanG7XIBhG9ybWn99P2Zaw1b9y O8ey53LIbmUFnPXg4kNy8lUsI2zTWHRds6tYxHk0r4Ybx6//oLmMxabFk9210QzonulzjD AmAfMp4meOKzfdp7wYzXocSCpoXioy7BVT1Ue3MmXFp3gOUAkoicyMm1/6ewgvoG8BC2mo fm0ZDOFWaEcMLP8jQVFZ3TvtlGrfisnO3Ru+ldwpeh0p5+QMew8cPDmILrNjzjFVTKgCwd pcSQUDS+DmazA95BRttdgnuSZsEXGirNWuaArmQJKrTZ9z0Zu4+/rwFKjtxxJw== X-Mailman-Original-Authentication-Results: smtp4.osuosl.org; dkim=pass (2048-bit key, unprotected) header.d=bootlin.com header.i=@bootlin.com header.a=rsa-sha256 header.s=gm1 header.b=O/XEyrCr Subject: Re: [Buildroot] [PATCH for-next 01/11] arch/Config.in.riscv: add Zicsr and Zifencei standalone extensions X-BeenThere: buildroot@buildroot.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussion and development of buildroot List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Thomas Petazzoni via buildroot Reply-To: Thomas Petazzoni Cc: Romain Naour , Mark Corbin , buildroot@buildroot.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: buildroot-bounces@buildroot.org Sender: "buildroot" Hello, On Sat, 23 Jul 2022 15:00:40 +0200 Romain Naour wrote: > I'm not familiar with the riscv instruction set, so I was not sure if we should > support the possibility to disable Zicsr and Zifencei standalone extensions with > gcc 12. AFIU, they are unconditionally enabled in previous gcc releases. Correct, which is why I think they will always be present in Linux-capable RISC-V cores. The reason I believe they were split from the I part of the ISA is because I is the base part of the ISA, and some people wanted to make RISC-V designs without those instructions, but not RISC-V designs targeting Linux. So for now, I think we should simply make the assumption that all RISC-V cores will have those instructions. If that turns out to be wrong in the future, we can always revisit that. > Additionally we have received two patches to add "vector operations extension" > > http://patchwork.ozlabs.org/project/buildroot/patch/20220704085552.3499243-2-abel@x-silicon.com/ > > http://patchwork.ozlabs.org/project/buildroot/patch/20220627135359.2232222-1-fhunleth@troodon-software.com/ > > But this requires gcc-12 > > http://patchwork.ozlabs.org/project/buildroot/patch/20220627135359.2232222-1-fhunleth@troodon-software.com/#2933736 > > Do you think "Vector Instructions (V)" deserve an option ? (I would say yes). Yes, V definitely needs an option, as there will clearly be Linux-capable RISC-V cores that do not implement the V extension. The option for the V extension will have to select BR2_ARCH_NEEDS_GCC_AT_LEAST_12. Best regards, Thomas -- Thomas Petazzoni, co-owner and CEO, Bootlin Embedded Linux and Kernel engineering and training https://bootlin.com _______________________________________________ buildroot mailing list buildroot@buildroot.org https://lists.buildroot.org/mailman/listinfo/buildroot