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 EC68AC433F5 for ; Mon, 25 Apr 2022 15:53:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243050AbiDYP4t (ORCPT ); Mon, 25 Apr 2022 11:56:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58904 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231857AbiDYP4q (ORCPT ); Mon, 25 Apr 2022 11:56:46 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9DD4F3A5D1 for ; Mon, 25 Apr 2022 08:53:41 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 3A69761142 for ; Mon, 25 Apr 2022 15:53:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1AC13C385A4; Mon, 25 Apr 2022 15:53:40 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="CDuL4RLG" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1650902018; 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: in-reply-to:in-reply-to:references:references; bh=TYv02nqT8LcvMlXJxnWlkxCIRFVS6R35nISm2N1D/HY=; b=CDuL4RLGyZ7VLwzmCoz+E+9yeneOLARHep/mZG8bYZZbYgLm4jYFeO1Upbf+ZL1mrm8WHD +65bni3Fgc9uise2MPPTDbelMDc+9qBBvgzEYIE+FpaBQIESoGHzw6eqErisxDORGuAxAz oXi6xk1XjYM9QSMxlgN9sxs86gOvNB8= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 01f09244 (TLSv1.3:AEAD-AES256-GCM-SHA384:256:NO); Mon, 25 Apr 2022 15:53:37 +0000 (UTC) Date: Mon, 25 Apr 2022 17:53:34 +0200 From: "Jason A. Donenfeld" To: Arnd Bergmann Cc: Linux Kernel Mailing List , Nick Desaulniers Subject: Re: odd endianness toolchains for crosstool Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Arnd, On Mon, Apr 25, 2022 at 05:39:34PM +0200, Arnd Bergmann wrote: > I can probably do that before migrating to the new machine, but I can't > promise how quickly I find time to start. Oh awesome. Will keep my eye out for it. > > (And also, build ppc32 with --enable-secureplt --with-long-double-64.) > > Can you explain what those are about? Is this related to the ELFv1 > vs ELFv2 difference or something else? Is this needed in both the > ppc32 and ppc64 compilers that each come with both targets? For 32-bit, it is required. From : powerpc (needs gcc built with --enable-secureplt --with-long-double-64, and -Wl,--secure-plt to link dynamic binaries.) And from the INSTALL file it says: * PowerPC * Compiler toolchain must provide 64-bit long double, not IBM double-double or IEEE quad * For dynamic linking, compiler toolchain must be configured for "secure PLT" variant For 64-bit, I'm not sure, but I know that at least -mabi=elfv2 is required, and I think --with-long-double-64 too, according to documentation: * PowerPC64 * Both little and big endian variants are supported * Compiler toolchain must provide 64-bit long double, not IBM double-double or IEEE quad * Compiler toolchain must use the new (ELFv2) ABI regardless of whether it is for little or big endian Taken from . Jason