From patchwork Wed Jul 26 14:50:46 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Zhangjin Wu X-Patchwork-Id: 707298 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 8A966C001DC for ; Wed, 26 Jul 2023 14:52:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233701AbjGZOwC (ORCPT ); Wed, 26 Jul 2023 10:52:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38226 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232277AbjGZOwA (ORCPT ); Wed, 26 Jul 2023 10:52:00 -0400 Received: from bg4.exmail.qq.com (bg4.exmail.qq.com [43.155.65.254]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BCD7D19A0; Wed, 26 Jul 2023 07:51:58 -0700 (PDT) X-QQ-mid: bizesmtp74t1690383109tpb94mlh Received: from localhost.localdomain ( [61.141.78.189]) by bizesmtp.qq.com (ESMTP) with id ; Wed, 26 Jul 2023 22:51:48 +0800 (CST) X-QQ-SSF: 01200000000000D0X000000A0000000 X-QQ-FEAT: OtIeQkg1QQHHCIiiAVCObq1XZpMiZZrep3CdnHIkv0Cbq1h4RDrOm7rMYOmUZ TPmC2nvXS5zvaOqkRcYFP7EfRTxQFyzdfssN9/Zr9xCoiY3tRyPj8srSEwFivyx8xeQaLQX b3Odf2maFdKYvMj0gCu2tmb4PLz2APzE+8iPcs1RsXJWOiOSXyUWSY4BvsyCLc/90ENTR0t vkfEksPIiQbt4oShglA/Z3TXba5fVnLCA5jXsgBn4u+TmtrrxNqAHTiAvJBk9QW/oXJw0GX yHdj+I2fEEDUD8nlIrzcPleDk+h/UglC9Cr8TQPiTBTknIe75gEv+IJOBa/s3LWCAetWPu1 JqzNl/k0pRQXeSgeoZ6pjTQJDInAolTF/IwBwWez3jMOCp2mJukfmi+T11QwA== X-QQ-GoodBg: 0 X-BIZMAIL-ID: 1055855130666732953 From: Zhangjin Wu To: w@1wt.eu Cc: falcon@tinylab.org, arnd@arndb.de, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, thomas@t-8ch.de, =?utf-8?q?Thomas_Wei?= =?utf-8?q?=C3=9Fschuh?= Subject: [PATCH v2 2/7] tools/nolibc: add support for powerpc64 Date: Wed, 26 Jul 2023 22:50:46 +0800 Message-Id: <7a406115cb891105e554d2bebb3532a5de70f5ca.1690373704.git.falcon@tinylab.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 X-QQ-SENDSIZE: 520 Feedback-ID: bizesmtp:tinylab.org:qybglogicsvrgz:qybglogicsvrgz5a-1 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org This follows the 64-bit PowerPC ABI [1], refers to the slides: "A new ABI for little-endian PowerPC64 Design & Implementation" [2] and the musl code in arch/powerpc64/crt_arch.h. Firstly, stdu and clrrdi are used instead of stwu and clrrwi for powerpc64. Second, the stack frame size is increased to 32 bytes for powerpc64, 32 bytes is the minimal stack frame size supported described in [2]. Besides, the TOC pointer (GOT pointer) must be saved to r2. This works on both little endian and big endian 64-bit PowerPC. [1]: https://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi.pdf [2]: https://www.llvm.org/devmtg/2014-04/PDFs/Talks/Euro-LLVM-2014-Weigand.pdf Reviewed-by: Thomas Weißschuh Signed-off-by: Zhangjin Wu --- tools/include/nolibc/arch-powerpc.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/tools/include/nolibc/arch-powerpc.h b/tools/include/nolibc/arch-powerpc.h index caa943e1521a..d783ed0b5dbd 100644 --- a/tools/include/nolibc/arch-powerpc.h +++ b/tools/include/nolibc/arch-powerpc.h @@ -175,6 +175,19 @@ /* startup code */ void __attribute__((weak, noreturn, optimize("Os", "omit-frame-pointer"))) __no_stack_protector _start(void) { +#ifdef __powerpc64__ + /* On 64-bit PowerPC, save TOC/GOT pointer to r2 */ + extern char TOC __asm__ (".TOC."); + register volatile long r2 __asm__ ("r2") = (void *)&TOC - (void *)_start; + + __asm__ volatile ( + "mr 3, 1\n" /* save stack pointer to r3, as arg1 of _start_c */ + "clrrdi 1, 1, 4\n" /* align the stack to 16 bytes */ + "li 0, 0\n" /* zero the frame pointer */ + "stdu 1, -32(1)\n" /* the initial stack frame */ + "bl _start_c\n" /* transfer to c runtime */ + ); +#else __asm__ volatile ( "mr 3, 1\n" /* save stack pointer to r3, as arg1 of _start_c */ "clrrwi 1, 1, 4\n" /* align the stack to 16 bytes */ @@ -182,6 +195,7 @@ void __attribute__((weak, noreturn, optimize("Os", "omit-frame-pointer"))) __no_ "stwu 1, -16(1)\n" /* the initial stack frame */ "bl _start_c\n" /* transfer to c runtime */ ); +#endif __builtin_unreachable(); }