[tip:x86/acpi] ACPI: Document ACPI table overriding via initrd
Commit-ID: 8347bbecf3518aa1518f6157e661812a35775130
Gitweb: http://git.kernel.org/tip/8347bbecf3518aa1518f6157e661812a35775130
Author: Thomas Renninger
AuthorDate: Mon, 1 Oct 2012 00:23:57 +0200
Committer: H. Peter Anvin
CommitDate: Sun, 30 Sep 2012 18:03:41 -0700
ACPI: Document ACPI table overriding via initrd
Signed-off-by: Thomas Renninger
Link: http://lkml.kernel.org/r/1349043837-22659-7-git-send-email-tr...@suse.de
Cc: Len Brown
Cc: Robert Moore
Cc: Yinghai Lu
Cc: Eric Piel
Signed-off-by: H. Peter Anvin
---
Documentation/acpi/initrd_table_override.txt | 94 ++
1 files changed, 94 insertions(+), 0 deletions(-)
diff --git a/Documentation/acpi/initrd_table_override.txt
b/Documentation/acpi/initrd_table_override.txt
new file mode 100644
index 000..35c3f54
--- /dev/null
+++ b/Documentation/acpi/initrd_table_override.txt
@@ -0,0 +1,94 @@
+Overriding 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_INITRD_TABLE_OVERRIDE compile option is true, it is possible to
+override nearly any ACPI table provided by the BIOS with an instrumented,
+modified one.
+
+For a full list of ACPI tables that can be overridden, take a look at
+the char *table_sigs[MAX_ACPI_SIGNATURE]; definition in drivers/acpi/osl.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
+---
+
+Please keep in mind that this is a debug option.
+ACPI tables should not get overridden for productive use.
+If BIOS ACPI tables are overridden the kernel will get tainted with the
+TAINT_OVERRIDDEN_ACPI_TABLE flag.
+Complain to your platform/BIOS vendor if you find a bug which is so sever
+that a workaround is not accepted in the Linux kernel.
+
+Still, it can and should be enabled in any kernel, because:
+ - There is no functional change with not instrumented initrds
+ - It provides a powerful feature to easily debug and test ACPI BIOS table
+compatibility with the Linux kernel.
+
+
+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)
+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.
+# The uncompressed cpio archive must be the first.
+# Other, typically compressed cpio archives, must be
+# concatenated on top of the uncompressed one.
+mkdir -p kernel/firmware/acpi
+cp dsdt.aml kernel/firmware/acpi
+# A maximum of: #define ACPI_OVERRIDE_TABLES 10
+# 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
+# Create the uncompressed cpio archive and concatenate 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=0x
+# 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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[tip:x86/acpi] ACPI: Document ACPI table overriding via initrd
Commit-ID: 8347bbecf3518aa1518f6157e661812a35775130 Gitweb: http://git.kernel.org/tip/8347bbecf3518aa1518f6157e661812a35775130 Author: Thomas Renninger tr...@suse.de AuthorDate: Mon, 1 Oct 2012 00:23:57 +0200 Committer: H. Peter Anvin h...@linux.intel.com CommitDate: Sun, 30 Sep 2012 18:03:41 -0700 ACPI: Document ACPI table overriding via initrd Signed-off-by: Thomas Renninger tr...@suse.de Link: http://lkml.kernel.org/r/1349043837-22659-7-git-send-email-tr...@suse.de Cc: Len Brown l...@kernel.org Cc: Robert Moore robert.mo...@intel.com Cc: Yinghai Lu ying...@kernel.org Cc: Eric Piel eric.p...@tremplin-utc.net Signed-off-by: H. Peter Anvin h...@linux.intel.com --- Documentation/acpi/initrd_table_override.txt | 94 ++ 1 files changed, 94 insertions(+), 0 deletions(-) diff --git a/Documentation/acpi/initrd_table_override.txt b/Documentation/acpi/initrd_table_override.txt new file mode 100644 index 000..35c3f54 --- /dev/null +++ b/Documentation/acpi/initrd_table_override.txt @@ -0,0 +1,94 @@ +Overriding 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_INITRD_TABLE_OVERRIDE compile option is true, it is possible to +override nearly any ACPI table provided by the BIOS with an instrumented, +modified one. + +For a full list of ACPI tables that can be overridden, take a look at +the char *table_sigs[MAX_ACPI_SIGNATURE]; definition in drivers/acpi/osl.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 +--- + +Please keep in mind that this is a debug option. +ACPI tables should not get overridden for productive use. +If BIOS ACPI tables are overridden the kernel will get tainted with the +TAINT_OVERRIDDEN_ACPI_TABLE flag. +Complain to your platform/BIOS vendor if you find a bug which is so sever +that a workaround is not accepted in the Linux kernel. + +Still, it can and should be enabled in any kernel, because: + - There is no functional change with not instrumented initrds + - It provides a powerful feature to easily debug and test ACPI BIOS table +compatibility with the Linux kernel. + + +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) +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. +# The uncompressed cpio archive must be the first. +# Other, typically compressed cpio archives, must be +# concatenated on top of the uncompressed one. +mkdir -p kernel/firmware/acpi +cp dsdt.aml kernel/firmware/acpi +# A maximum of: #define ACPI_OVERRIDE_TABLES 10 +# 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 +# Create the uncompressed cpio archive and concatenate 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=0x +# 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 -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[tip:x86/acpi] ACPI: Document ACPI table overriding via initrd
Commit-ID: 4901b402c957d4ebaff123ffc34fafe3cef99542
Gitweb: http://git.kernel.org/tip/4901b402c957d4ebaff123ffc34fafe3cef99542
Author: Thomas Renninger
AuthorDate: Wed, 26 Sep 2012 14:19:01 +0200
Committer: H. Peter Anvin
CommitDate: Thu, 27 Sep 2012 15:01:43 -0700
ACPI: Document ACPI table overriding via initrd
Signed-off-by: Thomas Renninger
Link: http://lkml.kernel.org/r/1348661941-71287-7-git-send-email-tr...@suse.de
Cc: Len Brown
Cc: Robert Moore
Cc: Yinghai Lu
Cc: Eric Piel
Signed-off-by: H. Peter Anvin
---
Documentation/acpi/initrd_table_override.txt | 94 ++
1 files changed, 94 insertions(+), 0 deletions(-)
diff --git a/Documentation/acpi/initrd_table_override.txt
b/Documentation/acpi/initrd_table_override.txt
new file mode 100644
index 000..35c3f54
--- /dev/null
+++ b/Documentation/acpi/initrd_table_override.txt
@@ -0,0 +1,94 @@
+Overriding 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_INITRD_TABLE_OVERRIDE compile option is true, it is possible to
+override nearly any ACPI table provided by the BIOS with an instrumented,
+modified one.
+
+For a full list of ACPI tables that can be overridden, take a look at
+the char *table_sigs[MAX_ACPI_SIGNATURE]; definition in drivers/acpi/osl.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
+---
+
+Please keep in mind that this is a debug option.
+ACPI tables should not get overridden for productive use.
+If BIOS ACPI tables are overridden the kernel will get tainted with the
+TAINT_OVERRIDDEN_ACPI_TABLE flag.
+Complain to your platform/BIOS vendor if you find a bug which is so sever
+that a workaround is not accepted in the Linux kernel.
+
+Still, it can and should be enabled in any kernel, because:
+ - There is no functional change with not instrumented initrds
+ - It provides a powerful feature to easily debug and test ACPI BIOS table
+compatibility with the Linux kernel.
+
+
+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)
+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.
+# The uncompressed cpio archive must be the first.
+# Other, typically compressed cpio archives, must be
+# concatenated on top of the uncompressed one.
+mkdir -p kernel/firmware/acpi
+cp dsdt.aml kernel/firmware/acpi
+# A maximum of: #define ACPI_OVERRIDE_TABLES 10
+# 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
+# Create the uncompressed cpio archive and concatenate 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=0x
+# 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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[tip:x86/acpi] ACPI: Document ACPI table overriding via initrd
Commit-ID: 4901b402c957d4ebaff123ffc34fafe3cef99542 Gitweb: http://git.kernel.org/tip/4901b402c957d4ebaff123ffc34fafe3cef99542 Author: Thomas Renninger tr...@suse.de AuthorDate: Wed, 26 Sep 2012 14:19:01 +0200 Committer: H. Peter Anvin h...@linux.intel.com CommitDate: Thu, 27 Sep 2012 15:01:43 -0700 ACPI: Document ACPI table overriding via initrd Signed-off-by: Thomas Renninger tr...@suse.de Link: http://lkml.kernel.org/r/1348661941-71287-7-git-send-email-tr...@suse.de Cc: Len Brown l...@kernel.org Cc: Robert Moore robert.mo...@intel.com Cc: Yinghai Lu ying...@kernel.org Cc: Eric Piel eric.p...@tremplin-utc.net Signed-off-by: H. Peter Anvin h...@linux.intel.com --- Documentation/acpi/initrd_table_override.txt | 94 ++ 1 files changed, 94 insertions(+), 0 deletions(-) diff --git a/Documentation/acpi/initrd_table_override.txt b/Documentation/acpi/initrd_table_override.txt new file mode 100644 index 000..35c3f54 --- /dev/null +++ b/Documentation/acpi/initrd_table_override.txt @@ -0,0 +1,94 @@ +Overriding 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_INITRD_TABLE_OVERRIDE compile option is true, it is possible to +override nearly any ACPI table provided by the BIOS with an instrumented, +modified one. + +For a full list of ACPI tables that can be overridden, take a look at +the char *table_sigs[MAX_ACPI_SIGNATURE]; definition in drivers/acpi/osl.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 +--- + +Please keep in mind that this is a debug option. +ACPI tables should not get overridden for productive use. +If BIOS ACPI tables are overridden the kernel will get tainted with the +TAINT_OVERRIDDEN_ACPI_TABLE flag. +Complain to your platform/BIOS vendor if you find a bug which is so sever +that a workaround is not accepted in the Linux kernel. + +Still, it can and should be enabled in any kernel, because: + - There is no functional change with not instrumented initrds + - It provides a powerful feature to easily debug and test ACPI BIOS table +compatibility with the Linux kernel. + + +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) +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. +# The uncompressed cpio archive must be the first. +# Other, typically compressed cpio archives, must be +# concatenated on top of the uncompressed one. +mkdir -p kernel/firmware/acpi +cp dsdt.aml kernel/firmware/acpi +# A maximum of: #define ACPI_OVERRIDE_TABLES 10 +# 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 +# Create the uncompressed cpio archive and concatenate 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=0x +# 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 -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
