From patchwork Thu Jul 27 15:00:55 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Zhangjin Wu X-Patchwork-Id: 13330233 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 01182C41513 for ; Thu, 27 Jul 2023 15:01:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234125AbjG0PBb (ORCPT ); Thu, 27 Jul 2023 11:01:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46788 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234165AbjG0PBR (ORCPT ); Thu, 27 Jul 2023 11:01:17 -0400 Received: from bg4.exmail.qq.com (bg4.exmail.qq.com [43.154.54.12]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 369AC30E1; Thu, 27 Jul 2023 08:01:08 -0700 (PDT) X-QQ-mid: bizesmtp84t1690470057tpm9d056 Received: from linux-lab-host.localdomain ( [61.141.78.189]) by bizesmtp.qq.com (ESMTP) with id ; Thu, 27 Jul 2023 23:00:56 +0800 (CST) X-QQ-SSF: 01200000002000D0X000B00A0000000 X-QQ-FEAT: 5q30pvLz2ifSFQC7zAtcmth9BQ99F3QX7jMGoQfR1aNIOgCwn9uvi1jOuq6K5 0PuPYGvo/MV8ecWP78qlbHD5Awh9SpdMM/dij1uNd4CvRexxNDfexvqQSBSh2Gx0+JEeZ+Y NZGOLfnN2Q72xcYqj7hFOxdWUeT7TfAzG3gm13y+ZkO7eI4AWQ8ktTS8Yq0bd+AM4wt1wgv dZOpd8MvbaVt5IZYU79INQkqbWvU5PbeCA4X45OFVtOeLI4E8zkdfFq9efIB25HUOPCOeDX qw1kZdwDIGJqcSTg6i4GkDspbEI/UYdpVFmre2OMqG6HKLadRhxsQU4aqpwp/+x5JKCvLLZ tfZ5dugbMcB5eAaLWf5qbZVzlcrRoxqiz0n+a+kLIX8Va6VSg7Azn9v5YxnmS8nkDPegwS3 X-QQ-GoodBg: 0 X-BIZMAIL-ID: 14503850201614126736 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 v3 2/7] tools/nolibc: add support for powerpc64 Date: Thu, 27 Jul 2023 23:00:55 +0800 Message-Id: <6f9c496695b5d44a3a694abc571e183b80d9081d.1690468707.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. First, 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(); }