From patchwork Wed Jul 12 09:26:21 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhangjin Wu X-Patchwork-Id: 13309908 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 1B050EB64D9 for ; Wed, 12 Jul 2023 09:26:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232375AbjGLJ0g (ORCPT ); Wed, 12 Jul 2023 05:26:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43098 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231472AbjGLJ0f (ORCPT ); Wed, 12 Jul 2023 05:26:35 -0400 Received: from bg4.exmail.qq.com (bg4.exmail.qq.com [43.154.54.12]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4C2CE139; Wed, 12 Jul 2023 02:26:33 -0700 (PDT) X-QQ-mid: bizesmtp65t1689153983tfw3ppgx Received: from linux-lab-host.localdomain ( [116.30.126.249]) by bizesmtp.qq.com (ESMTP) with id ; Wed, 12 Jul 2023 17:26:22 +0800 (CST) X-QQ-SSF: 01200000000000D0W000000A0000000 X-QQ-FEAT: J5JfekO1WsgRU4ygyCVjfG7z8UE8RA1iZUoq0kLH35rSYGgxoEMOUOGjZ5p1S EdO21pohjNWgfdEETq7vfqSMT1owM1Rdi71J+ZJmkdlGW/Zz7Jt3AGGIB+RqUQf4j5RjjKu eLb1toMwR1qyBM+Esohypdl02V/1Px26IX0V46DbxxPteDN9pkG7DD4HD1uMibcVipDMiZD KuVDwTCTzF5hoSD3L4JYMfAz2qMwXk3Gw/wA9yV4Dn3zLL/BtMg6s7QMqfS+Blz46X9Tzha G2XBXoqtkHyTf/2s5ehE+oBn/4VSqRAaangw7FZjoa7u+NswjcyWmHj12xiCIG5bfjlXokA ZJa70BSv2jwFF8eIFar5bHpaFvFdCRgsJjZWI24y7kwnZCpKwKCAPPobMppDeQoi+xoecy1 X-QQ-GoodBg: 0 X-BIZMAIL-ID: 17537015007484594219 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 Subject: [PATCH v3 10/11] tools/nolibc: s390: shrink _start with _start_c Date: Wed, 12 Jul 2023 17:26:21 +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 move most of the _start operations to _start_c(). Signed-off-by: Zhangjin Wu --- tools/include/nolibc/arch-s390.h | 36 +++++--------------------------- 1 file changed, 5 insertions(+), 31 deletions(-) diff --git a/tools/include/nolibc/arch-s390.h b/tools/include/nolibc/arch-s390.h index a40424ba043e..051f3f4ed19b 100644 --- a/tools/include/nolibc/arch-s390.h +++ b/tools/include/nolibc/arch-s390.h @@ -9,6 +9,7 @@ #include #include "compiler.h" +#include "crt.h" /* Syscalls for s390: * - registers are 64-bit @@ -137,41 +138,14 @@ _arg1; \ }) -char **environ __attribute__((weak)); -const unsigned long *_auxv __attribute__((weak)); - /* startup code */ void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) __no_stack_protector _start(void) { __asm__ volatile ( - "lg %r2,0(%r15)\n" /* argument count */ - "la %r3,8(%r15)\n" /* argument pointers */ - - "xgr %r0,%r0\n" /* r0 will be our NULL value */ - /* search for envp */ - "lgr %r4,%r3\n" /* start at argv */ - "0:\n" - "clg %r0,0(%r4)\n" /* entry zero? */ - "la %r4,8(%r4)\n" /* advance pointer */ - "jnz 0b\n" /* no -> test next pointer */ - /* yes -> r4 now contains start of envp */ - "larl %r1,environ\n" - "stg %r4,0(%r1)\n" - - /* search for auxv */ - "lgr %r5,%r4\n" /* start at envp */ - "1:\n" - "clg %r0,0(%r5)\n" /* entry zero? */ - "la %r5,8(%r5)\n" /* advance pointer */ - "jnz 1b\n" /* no -> test next pointer */ - "larl %r1,_auxv\n" /* yes -> store value in _auxv */ - "stg %r5,0(%r1)\n" - - "aghi %r15,-160\n" /* allocate new stackframe */ - "xc 0(8,%r15),0(%r15)\n" /* clear backchain */ - "brasl %r14,main\n" /* ret value of main is arg to exit */ - "lghi %r1,1\n" /* __NR_exit */ - "svc 0\n" + "lgr %r2, %r15\n" /* save stack pointer to %r2, as arg1 of _start_c */ + "aghi %r15, -160\n" /* allocate new stackframe */ + "xc 0(8,%r15), 0(%r15)\n" /* clear backchain */ + "brasl %r14, _start_c\n" /* transfer to c runtime */ ); __builtin_unreachable(); }