From patchwork Sat Jul 8 15:31:03 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhangjin Wu X-Patchwork-Id: 13305683 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 1E5EAEB64DA for ; Sat, 8 Jul 2023 15:31:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229726AbjGHPbR (ORCPT ); Sat, 8 Jul 2023 11:31:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60578 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229552AbjGHPbQ (ORCPT ); Sat, 8 Jul 2023 11:31:16 -0400 Received: from bg4.exmail.qq.com (bg4.exmail.qq.com [43.154.54.12]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 361E890; Sat, 8 Jul 2023 08:31:15 -0700 (PDT) X-QQ-mid: bizesmtp86t1688830265t9d8l2g9 Received: from linux-lab-host.localdomain ( [116.30.131.119]) by bizesmtp.qq.com (ESMTP) with id ; Sat, 08 Jul 2023 23:31:03 +0800 (CST) X-QQ-SSF: 01200000000000D0W000000A0000000 X-QQ-FEAT: eEaWPhs2DhvhZjsqAkJMMlzDeo2Sh5soRzY51O43vfpZnHRFckDc/KC+Whroj xugcXLSy7ICVFoiqSeTqCxTxDobCGlqVytmjm0QCDA4tguduQfJzEfDRcxmIlotOOEJXxoc Szs+owZ8ZdluFmUsrVqHiJdJRNXczXWNaeeYPWWWTKlBKPSwP4H3fmn6kDuV7Jgf7IhvcyF Y8jIw9/qDAPT3SPiuBrsnURgvLq+VWA9y/xT93260LoCPfi+IHVypNKboYor7z24/ElvVLv p5L1kmZJ/ainACsUtabnDfg1JQfM14itwmu6i6doAuz2mSNSJfH/hiigypC77vcvFbn4tFc DiYkkoHr/ovqEbIBaEx5pATYUoVOXFT9LNZQ7ULn54b9FrgnXEpUdehQ8s64qqtJLxkPGgf X-QQ-GoodBg: 0 X-BIZMAIL-ID: 5492700503261273189 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 v2 05/12] tools/nolibc: arm/crt.h: shrink _start with _start_c Date: Sat, 8 Jul 2023 23:31:03 +0800 Message-Id: <3b38249bfc9d36db3f33e44b42d34740b9de100a.1688828139.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 move most of the _start operations to _start_c(). Signed-off-by: Zhangjin Wu --- tools/include/nolibc/arm/crt.h | 38 +++++----------------------------- 1 file changed, 5 insertions(+), 33 deletions(-) diff --git a/tools/include/nolibc/arm/crt.h b/tools/include/nolibc/arm/crt.h index 7b3b9e21e5c4..75c097027a80 100644 --- a/tools/include/nolibc/arm/crt.h +++ b/tools/include/nolibc/arm/crt.h @@ -12,40 +12,12 @@ void __attribute__((weak, noreturn, optimize("omit-frame-pointer"))) __no_stack_ { __asm__ volatile ( #ifdef _NOLIBC_STACKPROTECTOR - "bl __stack_chk_init\n" /* initialize stack protector */ + "bl __stack_chk_init\n" /* initialize stack protector */ #endif - "pop {%r0}\n" /* argc was in the stack */ - "mov %r1, %sp\n" /* argv = sp */ - - "add %r2, %r0, $1\n" /* envp = (argc + 1) ... */ - "lsl %r2, %r2, $2\n" /* * 4 ... */ - "add %r2, %r2, %r1\n" /* + argv */ - "ldr %r3, 1f\n" /* r3 = &environ (see below) */ - "str %r2, [r3]\n" /* store envp into environ */ - - "mov r4, r2\n" /* search for auxv (follows NULL after last env) */ - "0:\n" - "mov r5, r4\n" /* r5 = r4 */ - "add r4, r4, #4\n" /* r4 += 4 */ - "ldr r5,[r5]\n" /* r5 = *r5 = *(r4-4) */ - "cmp r5, #0\n" /* and stop at NULL after last env */ - "bne 0b\n" - "ldr %r3, 2f\n" /* r3 = &_auxv (low bits) */ - "str r4, [r3]\n" /* store r4 into _auxv */ - - "mov %r3, $8\n" /* AAPCS : sp must be 8-byte aligned in the */ - "neg %r3, %r3\n" /* callee, and bl doesn't push (lr=pc) */ - "and %r3, %r3, %r1\n" /* so we do sp = r1(=sp) & r3(=-8); */ - "mov %sp, %r3\n" - - "bl main\n" /* main() returns the status code, we'll exit with it. */ - "movs r7, $1\n" /* NR_exit == 1 */ - "svc $0x00\n" - ".align 2\n" /* below are the pointers to a few variables */ - "1:\n" - ".word environ\n" - "2:\n" - ".word _auxv\n" + "mov %r0, sp\n" /* save stack pointer to %r0, as arg1 of _start_c */ + "and ip, %r0, #-8\n" /* sp must be 8-byte aligned in the callee */ + "mov sp, ip\n" + "bl _start_c\n" /* transfer to c runtime */ ); __builtin_unreachable(); }