From patchwork Tue Apr 23 16:28:39 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Changbin Du X-Patchwork-Id: 10913353 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1D5A2112C for ; Tue, 23 Apr 2019 16:32:02 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0DB2B286A0 for ; Tue, 23 Apr 2019 16:32:02 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 021AF286BD; Tue, 23 Apr 2019 16:32:01 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 39F7F286AC for ; Tue, 23 Apr 2019 16:32:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728602AbfDWQbz (ORCPT ); Tue, 23 Apr 2019 12:31:55 -0400 Received: from mail-pl1-f196.google.com ([209.85.214.196]:37355 "EHLO mail-pl1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728005AbfDWQby (ORCPT ); Tue, 23 Apr 2019 12:31:54 -0400 Received: by mail-pl1-f196.google.com with SMTP id w23so7801161ply.4; Tue, 23 Apr 2019 09:31:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=ZXoJRFk4/FsFXYjZqJikYqnn78EMklZir9UIGRxhTdY=; b=BOANFBbdwl6pEMvyrDo5RfwlNnFsaerbK+7YONMs0Z30bra/kUkbeMuyWWBwfz6bld FZC106NTKLHLfDXAUd8W574k0HTgTjNITjILqOiEbTN94zsgZ1b5cCkDtghN79rXO0Wy IfCNVWmuMl8RBXU5S2rEwkCtFjX0F/b1ajhazHA6/rOAd/n1uT8XbH/ufrYuNoIZ6ON+ F7p0B1BqGtVvSbYmtcC1IHv+/hu4in6ysMvf9BXgtM8ZTyQBE92UGr/rkcYvxc3ZSzPT QNJxbdvPcBkS0YTm9nwOenKTHYHvQWafHuid/tIFHqgGdVo/o4xnHZIbEV+9ZcXGtxay laBA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=ZXoJRFk4/FsFXYjZqJikYqnn78EMklZir9UIGRxhTdY=; b=KhOVZovSZttJp2pAB9J/ku3k3q2X5TF2aXZm2/TwuCvOIS1uv8H1UpLTRE0lYwUm5a cXHrS56IdXpF8KTdvpolnMySYiA6EZk05sR3DmFioGrDSEcTdgQCLyllDxhiv94jaiqx Y1zMzUwg6MF0MEww3HUxN4T+hRPTEKgcqLrGCZVyKH2rKbX7NnZnkeFvCYH36Pzxi3yC SaMD1LYZ1Ui7vv5SigqbbXwI+pD1EajCKGHZHecqSmOsOId49gTkpEm9fnzG74bGRtL8 QdMUJmaiNzvXmTPDmVgMe+fBnLi2OII3OzzJkVoUu3CP9fJX/Ov7gwky3P9M6x8ScED6 9fjA== X-Gm-Message-State: APjAAAVUgf+miG5yC0DIx4Yr62HZVoq8ug5ULq61jwVZyQXzBFeAfUqU 7EAjCyAI7HSPMWjBGas+TKM= X-Google-Smtp-Source: APXvYqxryDztduzVdABaghH078sVJWHERPeRjlDUJwOVv76/9jUmBWTjrs8sflgBfMEv1osus8SV5A== X-Received: by 2002:a17:902:854c:: with SMTP id d12mr27297087plo.150.1556037113035; Tue, 23 Apr 2019 09:31:53 -0700 (PDT) Received: from localhost.localdomain ([104.238.181.70]) by smtp.gmail.com with ESMTPSA id v1sm24364801pff.81.2019.04.23.09.31.41 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 23 Apr 2019 09:31:52 -0700 (PDT) From: Changbin Du To: Jonathan Corbet Cc: Bjorn Helgaas , rjw@rjwysocki.net, linux-pci@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, x86@kernel.org, fenghua.yu@intel.com, linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org, linux-gpio@vger.kernel.org, mchehab+samsung@kernel.org, Changbin Du Subject: [PATCH v4 10/63] Documentation: ACPI: move initrd_table_override.txt to admin-guide/acpi and convert to reST Date: Wed, 24 Apr 2019 00:28:39 +0800 Message-Id: <20190423162932.21428-11-changbin.du@gmail.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190423162932.21428-1-changbin.du@gmail.com> References: <20190423162932.21428-1-changbin.du@gmail.com> MIME-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This converts the plain text documentation to reStructuredText format and add it to Sphinx TOC tree. No essential content change. Signed-off-by: Changbin Du Reviewed-by: Mauro Carvalho Chehab --- Documentation/acpi/initrd_table_override.txt | 111 ---------------- Documentation/admin-guide/acpi/index.rst | 1 + .../acpi/initrd_table_override.rst | 120 ++++++++++++++++++ 3 files changed, 121 insertions(+), 111 deletions(-) delete mode 100644 Documentation/acpi/initrd_table_override.txt create mode 100644 Documentation/admin-guide/acpi/initrd_table_override.rst diff --git a/Documentation/acpi/initrd_table_override.txt b/Documentation/acpi/initrd_table_override.txt deleted file mode 100644 index 30437a6db373..000000000000 --- a/Documentation/acpi/initrd_table_override.txt +++ /dev/null @@ -1,111 +0,0 @@ -Upgrading ACPI tables via initrd -================================ - -1) Introduction (What is this about) -2) What is this for -3) How does it work -4) References (Where to retrieve userspace tools) - -1) What is this about ---------------------- - -If the ACPI_TABLE_UPGRADE compile option is true, it is possible to -upgrade the ACPI execution environment that is defined by the ACPI tables -via upgrading the ACPI tables provided by the BIOS with an instrumented, -modified, more recent version one, or installing brand new ACPI tables. - -When building initrd with kernel in a single image, option -ACPI_TABLE_OVERRIDE_VIA_BUILTIN_INITRD should also be true for this -feature to work. - -For a full list of ACPI tables that can be upgraded/installed, take a look -at the char *table_sigs[MAX_ACPI_SIGNATURE]; definition in -drivers/acpi/tables.c. -All ACPI tables iasl (Intel's ACPI compiler and disassembler) knows should -be overridable, except: - - ACPI_SIG_RSDP (has a signature of 6 bytes) - - ACPI_SIG_FACS (does not have an ordinary ACPI table header) -Both could get implemented as well. - - -2) What is this for -------------------- - -Complain to your platform/BIOS vendor if you find a bug which is so severe -that a workaround is not accepted in the Linux kernel. And this facility -allows you to upgrade the buggy tables before your platform/BIOS vendor -releases an upgraded BIOS binary. - -This facility can be used by platform/BIOS vendors to provide a Linux -compatible environment without modifying the underlying platform firmware. - -This facility also provides a powerful feature to easily debug and test -ACPI BIOS table compatibility with the Linux kernel by modifying old -platform provided ACPI tables or inserting new ACPI tables. - -It can and should be enabled in any kernel because there is no functional -change with not instrumented initrds. - - -3) How does it work -------------------- - -# Extract the machine's ACPI tables: -cd /tmp -acpidump >acpidump -acpixtract -a acpidump -# Disassemble, modify and recompile them: -iasl -d *.dat -# For example add this statement into a _PRT (PCI Routing Table) function -# of the DSDT: -Store("HELLO WORLD", debug) -# And increase the OEM Revision. For example, before modification: -DefinitionBlock ("DSDT.aml", "DSDT", 2, "INTEL ", "TEMPLATE", 0x00000000) -# After modification: -DefinitionBlock ("DSDT.aml", "DSDT", 2, "INTEL ", "TEMPLATE", 0x00000001) -iasl -sa dsdt.dsl -# Add the raw ACPI tables to an uncompressed cpio archive. -# They must be put into a /kernel/firmware/acpi directory inside the cpio -# archive. Note that if the table put here matches a platform table -# (similar Table Signature, and similar OEMID, and similar OEM Table ID) -# with a more recent OEM Revision, the platform table will be upgraded by -# this table. If the table put here doesn't match a platform table -# (dissimilar Table Signature, or dissimilar OEMID, or dissimilar OEM Table -# ID), this table will be appended. -mkdir -p kernel/firmware/acpi -cp dsdt.aml kernel/firmware/acpi -# A maximum of "NR_ACPI_INITRD_TABLES (64)" tables are currently allowed -# (see osl.c): -iasl -sa facp.dsl -iasl -sa ssdt1.dsl -cp facp.aml kernel/firmware/acpi -cp ssdt1.aml kernel/firmware/acpi -# The uncompressed cpio archive must be the first. Other, typically -# compressed cpio archives, must be concatenated on top of the uncompressed -# one. Following command creates the uncompressed cpio archive and -# concatenates the original initrd on top: -find kernel | cpio -H newc --create > /boot/instrumented_initrd -cat /boot/initrd >>/boot/instrumented_initrd -# reboot with increased acpi debug level, e.g. boot params: -acpi.debug_level=0x2 acpi.debug_layer=0xFFFFFFFF -# and check your syslog: -[ 1.268089] ACPI: PCI Interrupt Routing Table [\_SB_.PCI0._PRT] -[ 1.272091] [ACPI Debug] String [0x0B] "HELLO WORLD" - -iasl is able to disassemble and recompile quite a lot different, -also static ACPI tables. - - -4) Where to retrieve userspace tools ------------------------------------- - -iasl and acpixtract are part of Intel's ACPICA project: -http://acpica.org/ -and should be packaged by distributions (for example in the acpica package -on SUSE). - -acpidump can be found in Len Browns pmtools: -ftp://kernel.org/pub/linux/kernel/people/lenb/acpi/utils/pmtools/acpidump -This tool is also part of the acpica package on SUSE. -Alternatively, used ACPI tables can be retrieved via sysfs in latest kernels: -/sys/firmware/acpi/tables diff --git a/Documentation/admin-guide/acpi/index.rst b/Documentation/admin-guide/acpi/index.rst index 3e041206089d..09e4e81e4fb7 100644 --- a/Documentation/admin-guide/acpi/index.rst +++ b/Documentation/admin-guide/acpi/index.rst @@ -8,3 +8,4 @@ the Linux ACPI support. .. toctree:: :maxdepth: 1 + initrd_table_override diff --git a/Documentation/admin-guide/acpi/initrd_table_override.rst b/Documentation/admin-guide/acpi/initrd_table_override.rst new file mode 100644 index 000000000000..0787b2b91ded --- /dev/null +++ b/Documentation/admin-guide/acpi/initrd_table_override.rst @@ -0,0 +1,120 @@ +.. SPDX-License-Identifier: GPL-2.0 + +================================ +Upgrading ACPI tables via initrd +================================ + +1) Introduction (What is this about) +2) What is this for +3) How does it work +4) References (Where to retrieve userspace tools) + +1) What is this about +===================== + +If the ACPI_TABLE_UPGRADE compile option is true, it is possible to +upgrade the ACPI execution environment that is defined by the ACPI tables +via upgrading the ACPI tables provided by the BIOS with an instrumented, +modified, more recent version one, or installing brand new ACPI tables. + +When building initrd with kernel in a single image, option +ACPI_TABLE_OVERRIDE_VIA_BUILTIN_INITRD should also be true for this +feature to work. + +For a full list of ACPI tables that can be upgraded/installed, take a look +at the char `*table_sigs[MAX_ACPI_SIGNATURE];` definition in +drivers/acpi/tables.c. + +All ACPI tables iasl (Intel's ACPI compiler and disassembler) knows should +be overridable, except: + + - ACPI_SIG_RSDP (has a signature of 6 bytes) + - ACPI_SIG_FACS (does not have an ordinary ACPI table header) + +Both could get implemented as well. + + +2) What is this for +=================== + +Complain to your platform/BIOS vendor if you find a bug which is so severe +that a workaround is not accepted in the Linux kernel. And this facility +allows you to upgrade the buggy tables before your platform/BIOS vendor +releases an upgraded BIOS binary. + +This facility can be used by platform/BIOS vendors to provide a Linux +compatible environment without modifying the underlying platform firmware. + +This facility also provides a powerful feature to easily debug and test +ACPI BIOS table compatibility with the Linux kernel by modifying old +platform provided ACPI tables or inserting new ACPI tables. + +It can and should be enabled in any kernel because there is no functional +change with not instrumented initrds. + + +3) How does it work +=================== +:: + + # Extract the machine's ACPI tables: + cd /tmp + acpidump >acpidump + acpixtract -a acpidump + # Disassemble, modify and recompile them: + iasl -d *.dat + # For example add this statement into a _PRT (PCI Routing Table) function + # of the DSDT: + Store("HELLO WORLD", debug) + # And increase the OEM Revision. For example, before modification: + DefinitionBlock ("DSDT.aml", "DSDT", 2, "INTEL ", "TEMPLATE", 0x00000000) + # After modification: + DefinitionBlock ("DSDT.aml", "DSDT", 2, "INTEL ", "TEMPLATE", 0x00000001) + iasl -sa dsdt.dsl + # Add the raw ACPI tables to an uncompressed cpio archive. + # They must be put into a /kernel/firmware/acpi directory inside the cpio + # archive. Note that if the table put here matches a platform table + # (similar Table Signature, and similar OEMID, and similar OEM Table ID) + # with a more recent OEM Revision, the platform table will be upgraded by + # this table. If the table put here doesn't match a platform table + # (dissimilar Table Signature, or dissimilar OEMID, or dissimilar OEM Table + # ID), this table will be appended. + mkdir -p kernel/firmware/acpi + cp dsdt.aml kernel/firmware/acpi + # A maximum of "NR_ACPI_INITRD_TABLES (64)" tables are currently allowed + # (see osl.c): + iasl -sa facp.dsl + iasl -sa ssdt1.dsl + cp facp.aml kernel/firmware/acpi + cp ssdt1.aml kernel/firmware/acpi + # The uncompressed cpio archive must be the first. Other, typically + # compressed cpio archives, must be concatenated on top of the uncompressed + # one. Following command creates the uncompressed cpio archive and + # concatenates the original initrd on top: + find kernel | cpio -H newc --create > /boot/instrumented_initrd + cat /boot/initrd >>/boot/instrumented_initrd + # reboot with increased acpi debug level, e.g. boot params: + acpi.debug_level=0x2 acpi.debug_layer=0xFFFFFFFF + # and check your syslog: + [ 1.268089] ACPI: PCI Interrupt Routing Table [\_SB_.PCI0._PRT] + [ 1.272091] [ACPI Debug] String [0x0B] "HELLO WORLD" + +iasl is able to disassemble and recompile quite a lot different, +also static ACPI tables. + + +4) Where to retrieve userspace tools +==================================== + +iasl and acpixtract are part of Intel's ACPICA project: +http://acpica.org/ + +and should be packaged by distributions (for example in the acpica package +on SUSE). + +acpidump can be found in Len Browns pmtools: +ftp://kernel.org/pub/linux/kernel/people/lenb/acpi/utils/pmtools/acpidump + +This tool is also part of the acpica package on SUSE. +Alternatively, used ACPI tables can be retrieved via sysfs in latest kernels: +/sys/firmware/acpi/tables