From patchwork Tue Jul 18 21:11:54 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhangjin Wu X-Patchwork-Id: 704210 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 3EBA6EB64DD for ; Tue, 18 Jul 2023 21:12:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231231AbjGRVMY (ORCPT ); Tue, 18 Jul 2023 17:12:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36100 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230419AbjGRVMT (ORCPT ); Tue, 18 Jul 2023 17:12:19 -0400 Received: from bg4.exmail.qq.com (bg4.exmail.qq.com [43.155.65.254]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0E7821FEE; Tue, 18 Jul 2023 14:12:05 -0700 (PDT) X-QQ-mid: bizesmtp67t1689714716ty3d409i Received: from linux-lab-host.localdomain ( [119.123.130.39]) by bizesmtp.qq.com (ESMTP) with id ; Wed, 19 Jul 2023 05:11:55 +0800 (CST) X-QQ-SSF: 01200000000000D0X000000A0000000 X-QQ-FEAT: znfcQSa1hKbIWy9/nudIS6dweUsnw6YVkjkrjXVuU+TODYlb+AgCL6pXkl2Fl tSsRaDf72WXJcU3KEzH9E4XSY2yEuk3T/diWm8Ne5HqGX0DrjpE477mcQpG4G5DFd9ODAOv uaikbHrw6qk530JkQ8AXJcHgiIds6d+3aJefPFODPpZsURPJhdgFwh0jQjZ/vmKkYggOmvg aszaovcQXFBHNKeguR9bBylNG6atlyI7bfvZaKxSTY+3RBNZwLkFtoz5htQh0d6mbj20RuF K+5rrb2HGie6OTmRGi4ibC/KnE/f91NZCFgxKvguB/uEmc1BehQ7DhvhA7zqSZvkzSXxWHD 9PT7i9S5yx9Zpsyo+xynEYrc3KrTZZkfVU5bd7OV511CmwkmBLBB7D8q7X6YQ== X-QQ-GoodBg: 0 X-BIZMAIL-ID: 11373982133652074623 From: Zhangjin Wu To: w@1wt.eu Cc: thomas@t-8ch.de, arnd@arndb.de, falcon@tinylab.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH v1 2/8] tools/nolibc: add support for powerpc64 Date: Wed, 19 Jul 2023 05:11:54 +0800 Message-Id: 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 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 100ec0f412dc..7b28ebcfcc23 100644 --- a/tools/include/nolibc/arch-powerpc.h +++ b/tools/include/nolibc/arch-powerpc.h @@ -143,6 +143,19 @@ /* 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 */ @@ -150,6 +163,7 @@ 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(); }