mirror of
https://github.com/adulau/aha.git
synced 2024-12-27 19:26:25 +00:00
ACPI: update DSDT override documentation
Signed-off-by: Len Brown <len.brown@intel.com>
This commit is contained in:
Len Brown
parent
9cbc796028
commit
d89e9d6b49
4 changed files with 66 additions and 111 deletions
|
|
@ -1,99 +0,0 @@
|
|||
ACPI Custom DSDT read from initramfs
|
||||
|
||||
2003 by Markus Gaugusch < dsdt at gaugusch dot at >
|
||||
Special thanks go to Thomas Renninger from SuSE, who updated the patch for
|
||||
2.6.0 and later modified it to read inside initramfs
|
||||
2004 - 2008 maintained by Eric Piel < eric dot piel at tremplin-utc dot net >
|
||||
|
||||
This option is intended for people who would like to hack their DSDT and don't
|
||||
want to recompile their kernel after every change. It can also be useful to
|
||||
distros which offers pre-compiled kernels and want to allow their users to use
|
||||
a modified DSDT. In the Kernel config, enable the initial RAM filesystem
|
||||
support (in General Setup) and enable ACPI_CUSTOM_DSDT_INITRD at the ACPI
|
||||
options (General Setup|ACPI Support|Read Custom DSDT from initramfs).
|
||||
|
||||
A custom DSDT (Differentiated System Description Table) is useful when your
|
||||
computer uses ACPI but problems occur due to broken implementation. Typically,
|
||||
your computer works but there are some troubles with the hardware detection or
|
||||
the power management. You can check that troubles come from errors in the DSDT by
|
||||
activating the ACPI debug option and reading the logs. This table is provided
|
||||
by the BIOS, therefore it might be a good idea to check for BIOS update on your
|
||||
vendor website before going any further. Errors are often caused by vendors
|
||||
testing their hardware only with Windows or because there is code which is
|
||||
executed only on a specific OS with a specific version and Linux hasn't been
|
||||
considered during the development.
|
||||
|
||||
Before you run away from customising your DSDT, you should note that already
|
||||
corrected tables are available for a fair amount of computers on this web-page:
|
||||
http://acpi.sf.net/dsdt . Be careful though, to work correctly a DSDT has to
|
||||
match closely the hardware, including the amount of RAM, the frequency of the
|
||||
processor and the PCI cards present! If you are part of the unluckies who
|
||||
cannot find their hardware in this database, you can modify your DSDT by
|
||||
yourself. This process is less painful than it sounds. Download the Intel ASL
|
||||
compiler/decompiler at http://www.intel.com/technology/IAPC/acpi/downloads.htm .
|
||||
As root, you then have to dump your DSDT and decompile it. By using the
|
||||
compiler messages as well as the kernel ACPI debug messages and the reference
|
||||
book (available at the Intel website and also at http://www.acpi.info), it is
|
||||
quite easy to obtain a fully working table.
|
||||
|
||||
Once your new DSDT is ready you'll have to add it to an initramfs so that the
|
||||
kernel can read the table at the very beginning of the boot. As the file has to
|
||||
be accessed very early during the boot process the initramfs has to be an
|
||||
initramfs. The file is contained into the initramfs under the name /DSDT.aml .
|
||||
To obtain such an initramfs, you might have to modify your initramfs script or
|
||||
you can add it later to the initramfs with the script appended to this
|
||||
document. The command will look like:
|
||||
initramfs-add-dsdt initramfs.img my-dsdt.aml
|
||||
|
||||
In case you don't use any initramfs, the possibilities you have are to either
|
||||
start using one (try mkinitrd or yaird), or use the "Include Custom DSDT"
|
||||
configure option to directly include your DSDT inside the kernel.
|
||||
|
||||
The message "Looking for DSDT in initramfs..." will tell you if the DSDT was
|
||||
found or not. If you need to update your DSDT, generate a new initramfs and
|
||||
perform the steps above. Don't forget that with Lilo, you'll have to re-run it.
|
||||
|
||||
|
||||
====================== Here starts initramfs-add-dsdt ==========================
|
||||
#!/bin/bash
|
||||
# Adds a DSDT file to the initrd (if it's an initramfs)
|
||||
# first argument is the name of archive
|
||||
# second argument is the name of the file to add
|
||||
# The file will be copied as /DSDT.aml
|
||||
|
||||
# 20060126: fix "Premature end of file" with some old cpio (Roland Robic)
|
||||
# 20060205: this time it should really work
|
||||
|
||||
# check the arguments
|
||||
if [ $# -ne 2 ]; then
|
||||
program_name=$(basename $0)
|
||||
echo "\
|
||||
$program_name: too few arguments
|
||||
Usage: $program_name initrd-name.img DSDT-to-add.aml
|
||||
Adds a DSDT file to an initrd (in initramfs format)
|
||||
|
||||
initrd-name.img: filename of the initrd in initramfs format
|
||||
DSDT-to-add.aml: filename of the DSDT file to add
|
||||
" 1>&2
|
||||
exit 1
|
||||
fi
|
||||
|
||||
# we should check it's an initramfs
|
||||
|
||||
tempcpio=$(mktemp -d)
|
||||
# cleanup on exit, hangup, interrupt, quit, termination
|
||||
trap 'rm -rf $tempcpio' 0 1 2 3 15
|
||||
|
||||
# extract the archive
|
||||
gunzip -c "$1" > "$tempcpio"/initramfs.cpio || exit 1
|
||||
|
||||
# copy the DSDT file at the root of the directory so that we can call it "/DSDT.aml"
|
||||
cp -f "$2" "$tempcpio"/DSDT.aml
|
||||
|
||||
# add the file
|
||||
cd "$tempcpio"
|
||||
(echo DSDT.aml | cpio --quiet -H newc -o -A -O "$tempcpio"/initramfs.cpio) || exit 1
|
||||
cd "$OLDPWD"
|
||||
|
||||
# re-compress the archive
|
||||
gzip -c "$tempcpio"/initramfs.cpio > "$1"
|
||||
15
Documentation/acpi/dsdt-override.txt
Normal file
15
Documentation/acpi/dsdt-override.txt
Normal file
|
|
@ -0,0 +1,15 @@
|
|||
Linux supports two methods of overriding the BIOS DSDT:
|
||||
|
||||
CONFIG_ACPI_CUSTOM_DSDT builds the image into the kernel.
|
||||
|
||||
CONFIG_ACPI_CUSTOM_DSDT_INITRD adds the image to the initrd.
|
||||
|
||||
When to use these methods is described in detail on the
|
||||
Linux/ACPI home page:
|
||||
http://www.lesswatts.org/projects/acpi/overridingDSDT.php
|
||||
|
||||
Note that if both options are used, the DSDT supplied
|
||||
by the INITRD method takes precedence.
|
||||
|
||||
Documentation/initramfs-add-dsdt.sh is provided for convenience
|
||||
for use with the CONFIG_ACPI_CUSTOM_DSDT_INITRD method.
|
||||
43
Documentation/acpi/initramfs-add-dsdt.sh
Executable file
43
Documentation/acpi/initramfs-add-dsdt.sh
Executable file
|
|
@ -0,0 +1,43 @@
|
|||
#!/bin/bash
|
||||
# Adds a DSDT file to the initrd (if it's an initramfs)
|
||||
# first argument is the name of archive
|
||||
# second argument is the name of the file to add
|
||||
# The file will be copied as /DSDT.aml
|
||||
|
||||
# 20060126: fix "Premature end of file" with some old cpio (Roland Robic)
|
||||
# 20060205: this time it should really work
|
||||
|
||||
# check the arguments
|
||||
if [ $# -ne 2 ]; then
|
||||
program_name=$(basename $0)
|
||||
echo "\
|
||||
$program_name: too few arguments
|
||||
Usage: $program_name initrd-name.img DSDT-to-add.aml
|
||||
Adds a DSDT file to an initrd (in initramfs format)
|
||||
|
||||
initrd-name.img: filename of the initrd in initramfs format
|
||||
DSDT-to-add.aml: filename of the DSDT file to add
|
||||
" 1>&2
|
||||
exit 1
|
||||
fi
|
||||
|
||||
# we should check it's an initramfs
|
||||
|
||||
tempcpio=$(mktemp -d)
|
||||
# cleanup on exit, hangup, interrupt, quit, termination
|
||||
trap 'rm -rf $tempcpio' 0 1 2 3 15
|
||||
|
||||
# extract the archive
|
||||
gunzip -c "$1" > "$tempcpio"/initramfs.cpio || exit 1
|
||||
|
||||
# copy the DSDT file at the root of the directory so that we can call it "/DSDT.aml"
|
||||
cp -f "$2" "$tempcpio"/DSDT.aml
|
||||
|
||||
# add the file
|
||||
cd "$tempcpio"
|
||||
(echo DSDT.aml | cpio --quiet -H newc -o -A -O "$tempcpio"/initramfs.cpio) || exit 1
|
||||
cd "$OLDPWD"
|
||||
|
||||
# re-compress the archive
|
||||
gzip -c "$tempcpio"/initramfs.cpio > "$1"
|
||||
|
||||
|
|
@ -263,8 +263,10 @@ config ACPI_CUSTOM_DSDT
|
|||
depends on !STANDALONE
|
||||
default n
|
||||
help
|
||||
This option is to load a custom ACPI DSDT
|
||||
If you don't know what that is, say N.
|
||||
This option supports a custom DSDT by linking it into the kernel.
|
||||
See Documentation/acpi/dsdt-override.txt
|
||||
|
||||
If unsure, say N.
|
||||
|
||||
config ACPI_CUSTOM_DSDT_FILE
|
||||
string "Custom DSDT Table file to include"
|
||||
|
|
@ -279,17 +281,11 @@ config ACPI_CUSTOM_DSDT_INITRD
|
|||
depends on BLK_DEV_INITRD
|
||||
default n
|
||||
help
|
||||
The DSDT (Differentiated System Description Table) often needs to be
|
||||
overridden because of broken BIOS implementations. If this feature is
|
||||
activated you will be able to provide a customized DSDT by adding it
|
||||
to your initramfs. If your mkinitrd tool does not support this feature
|
||||
a script is provided in the documentation. For more details see
|
||||
<file:Documentation/dsdt-initrd.txt> or <http://gaugusch.at/kernel.shtml>.
|
||||
If there is no table found, it will fall-back to the custom DSDT
|
||||
in-kernel (if activated) or to the DSDT from the BIOS.
|
||||
This option supports a custom DSDT by optionally loading it from initrd.
|
||||
See Documentation/acpi/dsdt-override.txt
|
||||
|
||||
Even if you do not need a new one at the moment, you may want to use a
|
||||
better DSDT later. It is safe to say Y here.
|
||||
If you are not using this feature now, but may use it later,
|
||||
it is safe to say Y here.
|
||||
|
||||
config ACPI_BLACKLIST_YEAR
|
||||
int "Disable ACPI for systems before Jan 1st this year" if X86_32
|
||||
|
|
|
|||
Loading…
Reference in a new issue