From patchwork Tue Aug 1 19:38:12 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Zhangjin Wu X-Patchwork-Id: 13337189 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 0D054C0015E for ; Tue, 1 Aug 2023 19:38:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229828AbjHATi0 (ORCPT ); Tue, 1 Aug 2023 15:38:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59506 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230335AbjHATiZ (ORCPT ); Tue, 1 Aug 2023 15:38:25 -0400 Received: from bg4.exmail.qq.com (bg4.exmail.qq.com [43.154.54.12]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ADD8419A8; Tue, 1 Aug 2023 12:38:23 -0700 (PDT) X-QQ-mid: bizesmtp81t1690918693tg2dq5ek Received: from linux-lab-host.localdomain ( [116.30.131.233]) by bizesmtp.qq.com (ESMTP) with id ; Wed, 02 Aug 2023 03:38:12 +0800 (CST) X-QQ-SSF: 01200000002000E0X000B00A0000000 X-QQ-FEAT: ILHsT53NKPj8ls9nBXhaMQdmUugA36bMela6yczSsq9f5iOfohgag2rYI/DM4 cX+y+nB9lugbsEcSFSzlkAkKr8S4Vlw1poG1xM3NW9j4VF3N5NYg25Gz/xPQK/Zjdu9rt+c W7IOsY1t2GanKBqRP49C9lmwsfGAT77Nbf/ceMWQPNDA1rOKRVq0LS5hlF5WLDobuoVGrZ7 0YiXICnjCO8JlfPm3jQn3/KfV/jXUFva6CjhP03G9wjAUtdXHBmK2/FzBkQ821QM/Dg98T3 9cqIyxUhQmIxEV/oLie5dGuVdim+euBiQ9ITptmtmzJ97A2YK4+zDyJwAVBVW3rO2r4wJCT YkuXu7MGXSmhPvG5NtshP49ua4TbfD72M5xpeZG7BzgyEHUhRpAWqEOyItFjg== X-QQ-GoodBg: 0 X-BIZMAIL-ID: 12236267546790964810 From: Zhangjin Wu To: thomas@t-8ch.de Cc: falcon@tinylab.org, arnd@arndb.de, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, w@1wt.eu, =?utf-8?q?Thomas_Wei=C3=9Fschuh?= Subject: [PATCH v4 02/12] tools/nolibc: add support for powerpc64 Date: Wed, 2 Aug 2023 03:38:12 +0800 Message-Id: <6f9c496695b5d44a3a694abc571e183b80d9081d.1690916314.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(); }