From patchwork Wed Jul 12 09:19:50 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhangjin Wu X-Patchwork-Id: 702105 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 642B7EB64D9 for ; Wed, 12 Jul 2023 09:20:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231716AbjGLJUG (ORCPT ); Wed, 12 Jul 2023 05:20:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36654 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231578AbjGLJUC (ORCPT ); Wed, 12 Jul 2023 05:20:02 -0400 Received: from bg4.exmail.qq.com (bg4.exmail.qq.com [43.154.54.12]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 70C89139; Wed, 12 Jul 2023 02:20:00 -0700 (PDT) X-QQ-mid: bizesmtp75t1689153591t4m7hhbh Received: from linux-lab-host.localdomain ( [116.30.126.249]) by bizesmtp.qq.com (ESMTP) with id ; Wed, 12 Jul 2023 17:19:50 +0800 (CST) X-QQ-SSF: 01200000000000D0W000000A0000000 X-QQ-FEAT: uGhnJwy6xZIttFNE7Y1G6BS+94JXqZJfIlXFCaabP2xXLECfQZ3BaGBSMm/IR NGCzIYlWnLkXTYKMoCzHgVtI1SBTHE9zAuWjLHH9wKFzqJuFZHLCr4fL45h4/YMd5ju4dIZ 5ABy2E/ms4YpCXYwtpJ+Ri6OwV0W0JZNuRO0p78K1tySDRnhvVYkIerPi5oJ+ZrTErnqtZD ldIr8vumsmcR2TGV09ciofi67DbgZjSLpaOSJqhqwD91vpoDD8AQcnJb91AK6VTO/8oOP4v a1cXAFizdBzZHVJJASYpRXPQslKbYvozXKwNbq20vudoZncGqCqkdlEVf0EkQmbUbyzYODd ECJDStT5M2CNQFnqbjA0OLuScaUJhgbCQPcjyTbZh0MH3OJ7iQFb0giFTpN3w== X-QQ-GoodBg: 0 X-BIZMAIL-ID: 5769694176344349855 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 04/11] tools/nolibc: aarch64: shrink _start with _start_c Date: Wed, 12 Jul 2023 17:19:50 +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-aarch64.h | 26 +++++--------------------- 1 file changed, 5 insertions(+), 21 deletions(-) diff --git a/tools/include/nolibc/arch-aarch64.h b/tools/include/nolibc/arch-aarch64.h index 1bf122cd5966..e52fa5a20d71 100644 --- a/tools/include/nolibc/arch-aarch64.h +++ b/tools/include/nolibc/arch-aarch64.h @@ -8,6 +8,7 @@ #define _NOLIBC_ARCH_AARCH64_H #include "compiler.h" +#include "crt.h" /* Syscalls for AARCH64 : * - registers are 64-bit @@ -143,33 +144,16 @@ _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 ( #ifdef _NOLIBC_STACKPROTECTOR - "bl __stack_chk_init\n" /* initialize stack protector */ + "bl __stack_chk_init\n" /* initialize stack protector */ #endif - "ldr x0, [sp]\n" /* argc (x0) was in the stack */ - "add x1, sp, 8\n" /* argv (x1) = sp */ - "lsl x2, x0, 3\n" /* envp (x2) = 8*argc ... */ - "add x2, x2, 8\n" /* + 8 (skip null) */ - "add x2, x2, x1\n" /* + argv */ - "adrp x3, environ\n" /* x3 = &environ (high bits) */ - "str x2, [x3, #:lo12:environ]\n" /* store envp into environ */ - "mov x4, x2\n" /* search for auxv (follows NULL after last env) */ - "0:\n" - "ldr x5, [x4], 8\n" /* x5 = *x4; x4 += 8 */ - "cbnz x5, 0b\n" /* and stop at NULL after last env */ - "adrp x3, _auxv\n" /* x3 = &_auxv (high bits) */ - "str x4, [x3, #:lo12:_auxv]\n" /* store x4 into _auxv */ - "and sp, x1, -16\n" /* sp must be 16-byte aligned in the callee */ - "bl main\n" /* main() returns the status code, we'll exit with it. */ - "mov x8, 93\n" /* NR_exit == 93 */ - "svc #0\n" + "mov x0, sp\n" /* save stack pointer to x0, as arg1 of _start_c */ + "and sp, x0, -16\n" /* sp must be 16-byte aligned in the callee */ + "bl _start_c\n" /* transfer to c runtime */ ); __builtin_unreachable(); }