[PATCH v6 10/24] Documentation: ACPI: move initrd_table_override.txt to admin-guide/acpi and convert to reST

Changbin Du
2019-04-25T15:31:03Z

Documentation/acpi/initrd_table_override.txt | 111 -----------------
Documentation/admin-guide/acpi/index.rst | 1 +
.../acpi/initrd_table_override.rst | 115 ++++++++++++++++++
3 files changed, 116 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..cbd768207631
--- /dev/null
+++ b/Documentation/admin-guide/acpi/initrd_table_override.rst
@@ -0,0 +1,115 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+================================
+Upgrading ACPI tables via initrd
+================================
+
+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.
+
+
+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.
+
+
+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.
+
+
+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
--
2.20.1