From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (lists.ozlabs.org [103.22.144.68]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 40F2QZ46CMzF22J for ; Mon, 2 Apr 2018 16:30:14 +1000 (AEST) Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) by bilbo.ozlabs.org (Postfix) with ESMTP id 40F2QZ1B03z8vSL for ; Mon, 2 Apr 2018 16:30:14 +1000 (AEST) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 40F2QY1F5Dz9s15 for ; Mon, 2 Apr 2018 16:30:12 +1000 (AEST) Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w326TW0x125366 for ; Mon, 2 Apr 2018 02:30:11 -0400 Received: from e06smtp11.uk.ibm.com (e06smtp11.uk.ibm.com [195.75.94.107]) by mx0b-001b2d01.pphosted.com with ESMTP id 2h3em91br7-1 (version=TLSv1.2 cipher=AES256-SHA256 bits=256 verify=NOT) for ; Mon, 02 Apr 2018 02:30:11 -0400 Received: from localhost by e06smtp11.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 2 Apr 2018 07:30:08 +0100 Subject: [PATCH v3 2/7] powerpc/fadump: Update documentation to reflect the metadata region movement. From: Mahesh J Salgaonkar To: linuxppc-dev Cc: Srikar Dronamraju , kernelfans@gmail.com, "Aneesh Kumar K.V" , Ananth Narayan , Hari Bathini , Nathan Fontenot , Anshuman Khandual Date: Mon, 02 Apr 2018 12:00:03 +0530 In-Reply-To: <152265046485.23251.1392824827444770657.stgit@jupiter.in.ibm.com> References: <152265046485.23251.1392824827444770657.stgit@jupiter.in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Message-Id: <152265060147.23251.3669620531517333403.stgit@jupiter.in.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Mahesh Salgaonkar Metadata region that holds fadump header and ELF header is now placed at the start of reserved memory area. Update the documentation accordingly Signed-off-by: Mahesh Salgaonkar --- Documentation/powerpc/firmware-assisted-dump.txt | 31 +++++++++++++--------- 1 file changed, 19 insertions(+), 12 deletions(-) diff --git a/Documentation/powerpc/firmware-assisted-dump.txt b/Documentation/powerpc/firmware-assisted-dump.txt index bdd344aa18d9..c77f8dc9231f 100644 --- a/Documentation/powerpc/firmware-assisted-dump.txt +++ b/Documentation/powerpc/firmware-assisted-dump.txt @@ -115,17 +115,24 @@ be kept permanently reserved, so that it can act as a receptacle for a copy of the boot memory content in addition to CPU state and HPTE region, in the case a crash does occur. +The first kernel, during fadump registration, prepares ELF core header +that contains necessary information for the coredump of the 1st kernel +which includes its physical memory layout. This ELF header and some more +additional data is stored in the area called metadata region at the start +of the reserved memory area. + o Memory Reservation during first kernel Low memory Top of memory 0 boot memory size | | | |<--Reserved dump area -->| | V V | Permanent Reservation | V - +-----------+----------/ /---+---+----+-----------+----+------+ - | | |CPU|HPTE| DUMP |ELF | | - +-----------+----------/ /---+---+----+-----------+----+------+ - | ^ - | | + +-----------+----------/ /---+----+---+----+-----------+------+ + | | |ELF |CPU|HPTE| DUMP | | + +-----------+---------/ /----+----+---+----+-----------+------+ + | ^ ^ + | | | + | metadata region | \ / ------------------------------------------- Boot memory content gets transferred to @@ -137,14 +144,14 @@ and HPTE region, in the case a crash does occur. Low memory Top of memory 0 boot memory size | - | |<------------- Reserved dump area ----------- -->| + | |<------------- Reserved dump area -------------->| V V V - +-----------+----------/ /---+---+----+-----------+----+------+ - | | |CPU|HPTE| DUMP |ELF | | - +-----------+----------/ /---+---+----+-----------+----+------+ - | | - V V - Used by second /proc/vmcore + +-----------+----------/ /---+----+----+---------------+------+ + | | |ELF |CPU|HPTE| DUMP | | + +-----------+----------/ /---+----+----+---------------+------+ + | | + V V + Used by second /proc/vmcore kernel to boot Fig. 2