From patchwork Sat Jul 8 15:29:58 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhangjin Wu X-Patchwork-Id: 117455 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:9f45:0:b0:3ea:f831:8777 with SMTP id v5csp4015651vqx; Sat, 8 Jul 2023 09:24:13 -0700 (PDT) X-Google-Smtp-Source: APBJJlGkjkGqzh6jgMPtGnETHIvehE/1Z6UG3EkA79ilqHDeG6Msq9bbHE5EAiV6eAiD7EKmOxCg X-Received: by 2002:a17:906:8f:b0:993:f2b4:13c9 with SMTP id 15-20020a170906008f00b00993f2b413c9mr994576ejc.21.1688833453679; Sat, 08 Jul 2023 09:24:13 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1688833453; cv=none; d=google.com; s=arc-20160816; b=ldBd9p/uJLE8zB/X2eKhAx4bZmqVLVgj4y/95xZ8IorZHivojVJ12E546oIs6wr1JM T9Ibz1uoCJeocMrtoKQNcx791j87xQ0kvyVuEbhJb1VNYXMaKBhBDd6cJKQ/EairSt17 1bmWeajoQf4Ft4hI/PaVddOCV4HEjuTdOHEHu9YCE/hk5VEHp5B05P/zRZcxWigJm1VQ zcmzK+b8vGcUq3v6e4kT9CTOkJZLaR28OALT3+PxYjxM4cvt6gcw3RqxBOACJceGa0Wi uaNKWo489YNLhkzUdtzoUmZt3boCbFvyA80bK1KXd2p8++/1oALWRJhpdnGKZkhqTBgW T/2Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:feedback-id:content-transfer-encoding :mime-version:references:in-reply-to:message-id:date:subject:cc:to :from; bh=USpn26gMPJ82lWO4xi2D0qRmi8aSDlQI7ozs9lbAGOs=; fh=kgRNfNE6xRCHBUX3iUlrLhv5pQPglsdZFzOkxo2Fhpc=; b=bE5ZmMCE6VZdaqriJBva9rHb0efKnlusY1j+NQPJ5oiyn2zQ9anMnPncDZktIGb6Ay LkvCUd+lc/vFVj7+0f7hrdn21yE89LNp78QU85C/3s64VIpps8MoxDh/pgL9GdW3SS7a q4XF0iRADgVXnoVeKqnq6Gg+9FlFcK614wtvybjSp6FtqtdKDnHAPfMC8vg0by62l6uL mGjJM5byrjjvpIyreZ2O8dFuM+bum3PMNusalGKxgLiM+fC6rhpqPSd3nmSU7yj3cn0J cnj+O+uhwI/YHSktloRPt9x7KHtlL8j0dpJr/H62Dc8FsQKCQwFYPPFmcuknDpkvcaQJ aUZA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id q6-20020a17090622c600b00992c195b499si3840819eja.765.2023.07.08.09.23.48; Sat, 08 Jul 2023 09:24:13 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230468AbjGHPaN (ORCPT + 99 others); Sat, 8 Jul 2023 11:30:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60188 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229726AbjGHPaL (ORCPT ); Sat, 8 Jul 2023 11:30:11 -0400 Received: from bg4.exmail.qq.com (bg4.exmail.qq.com [43.154.54.12]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 78DFF90; Sat, 8 Jul 2023 08:30:09 -0700 (PDT) X-QQ-mid: bizesmtp90t1688830199tddli4lm Received: from linux-lab-host.localdomain ( [116.30.131.119]) by bizesmtp.qq.com (ESMTP) with id ; Sat, 08 Jul 2023 23:29:58 +0800 (CST) X-QQ-SSF: 01200000000000D0W000000A0000000 X-QQ-FEAT: eSZ1CZgv+JDNSYVWcvAqpj0rMV65FuCWvkiqEsX0QCaJ3cmGvGHwqt4FW1NPz xtLYKx4fWntTwjgdLuKBjSAmdBqltgnFcnpV0Gg+dSUFOBuhWgGtMIVtlDJuRSOakTaDPyf DteElzUduQbDJaKPkaiv65kbJIwnbKHkk9XhbF7riP1SVSVYoxY855+ZD2A+7Kyh5RALGtG zeeesVIfP5H0OAey6/2Pp+ARRSKgkAwVv0n0wkl3AZDqzEyuojwi0WP8cSU2snSHpbwpFMf C/QtfST4aIERx7pL/R9uECvdoTwV9p5F2Zo/LtJSLRMdjKmijl9YEoGocgpClxQWlw6II3G 0TZNWf1ltkWlZULHAwSeTkDHf2JIuhfDfKj0rx2TIG3R52KWmXc2oQ7zS748Q== X-QQ-GoodBg: 0 X-BIZMAIL-ID: 10107616674853176489 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 04/12] tools/nolibc: crt.h: add _start_c Date: Sat, 8 Jul 2023 23:29:58 +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 X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,RCVD_IN_MSPIKE_H2, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1770870227504495300?= X-GMAIL-MSGID: =?utf-8?q?1770870227504495300?= As the environ and _auxv support added for nolibc, the assembly _start function becomes more and more complex and therefore makes the porting of nolibc to new architectures harder and harder. To simplify portability, this c version of _start_c() is added to do most of the assembly start operations in C, which reduces the complexity a lot and will eventually simplify the porting of nolibc to the new architectures. The new _start_c() only requires a stack pointer argument, it will find argv, envp and _auxv for us, and then call main(), finally, it exit() with main's return status. With this new _start_c(), the future new architectures only require to add very few assembly instructions. Signed-off-by: Zhangjin Wu --- tools/include/nolibc/crt.h | 44 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) diff --git a/tools/include/nolibc/crt.h b/tools/include/nolibc/crt.h index 221b7c5346ca..b269294e9664 100644 --- a/tools/include/nolibc/crt.h +++ b/tools/include/nolibc/crt.h @@ -13,4 +13,48 @@ char **environ __attribute__((weak)); const unsigned long *_auxv __attribute__((weak)); +int main(int argc, char *argv[], char **envp); +static void exit(int); + +void _start_c(long *sp) +{ + int argc, i; + char **argv; + char **envp; + + /* + * sp : argc <-- argument count, required by main() + * argv: argv[0] <-- argument vector, required by main() + * argv[1] + * ... + * argv[argc-1] + * null + * envp: envp[0] <-- environment variables, required by main() and getenv() + * envp[1] + * ... + * null + * _auxv: auxv[0] <-- auxiliary vector, required by getauxval() + * auxv[1] + * ... + * null + */ + + /* assign argc and argv */ + argc = sp[0]; + argv = (void *)(sp + 1); + + /* find envp */ + envp = argv + argc + 1; + environ = envp; + + /* find auxv */ + i = 0; + while (envp[i]) + i++; + _auxv = (void *)(envp + i + 1); + + /* go to application */ + exit(main(argc, argv, envp)); +} + #endif /* _NOLIBC_CRT_H */