From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from SNT004-OMC3S15.hotmail.com (snt004-omc3s15.hotmail.com [65.55.90.154]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id A3A7B1A1E04 for ; Fri, 12 Aug 2016 19:01:23 -0700 (PDT) Received: from EUR01-DB5-obe.outbound.protection.outlook.com ([65.55.90.135]) by SNT004-OMC3S15.hotmail.com over TLS secured channel with Microsoft SMTPSVC(7.5.7601.23008); Fri, 12 Aug 2016 19:01:22 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=outlook.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version; bh=CGnyx8PA2iY6BN6qbjh7b+o/5VdXw9B9bFfRW+7XJF8=; b=XdYDMSALTh0HrWtdARITtmm8TLlXinyRfQDvxjJpB/mLaZiGpUxZ5USYkWGwPqrLKWDu5/wpegyP65mddEmQ91WOvizBmy2VgLBTkicf4k15a/+qHLFhWCmXizAWtPpxJfvaAXN3PCQkROLJJ8AM7yNTHX3jmDtRSopZt/2qYoVmE6MetxDfAv9lLueQ1sdhuTBQ9P/aS9PNMDNvuaSQXjqhATt5gcmLiyAqWToK6M7455R7EH7LY5CmChMbQJMYPbvax3j4J9Bi/p6QaWwnvSu7SRD8oXrNbxqcaYCcDNbCfgctnkCOLRiNvl8C6465Hi8ZZM2xSjgeyX+KOq63LA== Received: from DB5EUR01FT014.eop-EUR01.prod.protection.outlook.com (10.152.4.51) by DB5EUR01HT254.eop-EUR01.prod.protection.outlook.com (10.152.5.137) with Microsoft SMTP Server (version=TLS1_0, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA_P384) id 15.1.567.7; Sat, 13 Aug 2016 02:01:20 +0000 Received: from VI1PR06MB1792.eurprd06.prod.outlook.com (10.152.4.56) by DB5EUR01FT014.mail.protection.outlook.com (10.152.4.242) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384_P384) id 15.1.567.7 via Frontend Transport; Sat, 13 Aug 2016 02:01:20 +0000 Received: from VI1PR06MB1792.eurprd06.prod.outlook.com ([10.165.237.146]) by VI1PR06MB1792.eurprd06.prod.outlook.com ([10.165.237.146]) with mapi id 15.01.0549.026; Sat, 13 Aug 2016 02:01:19 +0000 From: Marvin H?user To: "edk2-devel@lists.01.org" Thread-Topic: [MdeModulePkg/PeiCore] How is Data being NULL on entry ensured? Thread-Index: AdH1BdSpJ+9du7JZRbSQtflX5i7n1Q== Date: Sat, 13 Aug 2016 02:01:19 +0000 Message-ID: Accept-Language: de-DE, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: authentication-results: spf=softfail (sender IP is 10.152.4.56) smtp.mailfrom=outlook.com; lists.01.org; dkim=none (message not signed) header.d=none;lists.01.org; dmarc=fail action=none header.from=outlook.com; received-spf: SoftFail (protection.outlook.com: domain of transitioning outlook.com discourages use of 10.152.4.56 as permitted sender) x-ms-exchange-messagesentrepresentingtype: 1 x-tmn: [rS+k8fve6hG5Pgs1/zpVKJumQMDL5unX8PXpSF8qj91g/TPiT19bvVMOt+4RCB0z] x-eopattributedmessage: 0 x-forefront-antispam-report: CIP:10.152.4.56; IPV:NLI; CTRY:; EFV:NLI; SFV:NSPM; SFS:(10019020)(98900003); DIR:OUT; SFP:1102; SCL:1; SRVR:DB5EUR01HT254; H:VI1PR06MB1792.eurprd06.prod.outlook.com; FPR:; SPF:None; LANG:en; x-microsoft-exchange-diagnostics: 1; DB5EUR01HT254; 6:LEkwc0Iv8H175GN+06IP4UDY1FYThhh1Ot1a2AFl7NiPZEP9MaFf5dydo6HiSuVnEH0HRQZ7q0xjwOFK8BDTf6tGcgQamwnXvQ8jOLslkBJhftJHe6HiW38uekphAebjDuT1kxBoRlTcvYyPmV9YR5L5Ve5kwr/qF6IF1n0hvgapRIPrTpIN8rL1Zm8Wzfyi/PnvvS+PewNw2Fxt7+mBMn1S+dIAgA6Qy8OHhRGlLJa7Shf70jXkzndl48TOQUu3phuUDKcS6sxm7353FrgPlfrQxOi4bRikjprBpJpqyDGlbgZNYXiCmMi6HONJdBOR; 5:bNFaELGH/Y2C8/1osxFeJFPlOh/EsYZJRWhv44RM9XgahCNh7ebCWTLFlq+SI6H6C4AbiKU+9q3hTvN9eZcStdFdC3UsYjAFFgd3aLemQfoC+mf3RVmn3ehcfVJneKD4PMWnh5NVmLAPmgT22MhctA==; 24:wcweGy3Rjd286OLOdUSq4NY+Bm7BFmkZG/XJpGcypM9qaGNXA9wXXXnqPM8f23NOX/ILkbrQ2JZ0G2tj073xWPMouqs2PoO9d2KUtHQWzrY=; 7:/ldVqX0x4N7qK59jvUNVuUFaPCdv25ZlSnoumOPsLeTC2LQ/IMkqa6Z34mpLLQvLGWCdxTuG0paM8DO2Tlav0YJz+wc9iVDclsgbqJmp/sgLYPf08pawujEEz6oYsi9sTXwQs1QIqibfd24qvG6tLvbsxTPP7qFrOX+u1fdbabVCovIst5qJ82OVg4aFGnNi4rkXA4s765G4hzThXGW7/JX+I55SsoMMitVbp2bFsr3g9SJX/ZSsDtdOou4zLBwU x-ms-office365-filtering-correlation-id: 1f6f331d-eb6e-48dc-ca60-08d3c31db7c3 x-microsoft-antispam: UriScan:; BCL:0; PCL:0; RULEID:(1601125047); SRVR:DB5EUR01HT254; x-exchange-antispam-report-cfa-test: BCL:0; PCL:0; RULEID:(432015012)(82015046); SRVR:DB5EUR01HT254; BCL:0; PCL:0; RULEID:; SRVR:DB5EUR01HT254; x-forefront-prvs: 0033AAD26D spamdiagnosticoutput: 1:99 spamdiagnosticmetadata: NSPM MIME-Version: 1.0 X-OriginatorOrg: outlook.com X-MS-Exchange-CrossTenant-originalarrivaltime: 13 Aug 2016 02:01:19.2220 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Internet X-MS-Exchange-CrossTenant-id: 84df9e7f-e9f6-40af-b435-aaaaaaaaaaaa X-MS-Exchange-Transport-CrossTenantHeadersStamped: DB5EUR01HT254 X-OriginalArrivalTime: 13 Aug 2016 02:01:22.0865 (UTC) FILETIME=[975F0210:01D1F506] X-Content-Filtered-By: Mailman/MimeDel 2.1.21 Subject: [MdeModulePkg/PeiCore] How is Data being NULL on entry ensured? X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 13 Aug 2016 02:01:23 -0000 Content-Language: de-DE Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Dear list subscribers, I have just been looking around the PeiCore code and wondered, how it is en= sured, that the third ("Data") argument of the entry point is NULL on the f= irst run. EFI_PEI_CORE_ENTRY_POINT only has two arguments and hence most SEC implemen= tations, including MdeModulePkg/SecCore, are going to pass only the first t= wo arguments to the entry point. I'm aware that the code works and I have never seen an occasion of it faili= ng or seeming to fail because of this design, though I wondered, how is it = assured, that the third argument, which is not part of the first call, is b= eing NULL on entry and not some leftover on the temporary stack/in the argu= ment 3 register? Thank you for your time! Regards, Marvin.