Commit graph

44 commits

Author SHA1 Message Date
Simon Glass
2e977b2ce8 Reland "x86: Move FACP table into separate functions""
Each board has its own way of creating this table. Rather than calling the
acpi_create_fadt() function for each one from a common acpi_write_fadt()
function, just move the writer into the board-specific code.

Co-developed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Simon Glass <sjg@chromium.org>
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2023-09-22 06:03:46 +08:00
Andy Shevchenko
ce1cbf1ae0 Revert "x86: Move FACP table into separate functions"
Before the culprit patch (see BugLink for the details):

  => acpi list
  Name      Base   Size  Detail
  ----  --------  -----  ------
  RSDP  000e4500     24  v02 U-BOOT
  RSDT  000e4530     38  v01 U-BOOT U-BOOTBL 20220401 INTL 0
  XSDT  000e45e0     4c  v01 U-BOOT U-BOOTBL 20220401 INTL 0
  CSRT  000e5490     58  v00 U-BOOT U-BOOTBL 20220401 INTL 0
  FACP  000e54f0    114  v06 U-BOOT U-BOOTBL 20220401 INTL 0
  DSDT  000e4780    c06  v02 U-BOOT U-BOOTBL 10000 INTL 20200925
  FACS  000e4740     40
  MCFG  000e5610     3c  v01 U-BOOT U-BOOTBL 20220401 INTL 0
  SPCR  000e5650     50  v02 U-BOOT U-BOOTBL 20220401 INTL 0
  APIC  000e56a0     48  v02 U-BOOT U-BOOTBL 20220401 INTL 0

After the culprit patch:

  => acpi list
  Name      Base   Size  Detail
  ----  --------  -----  ------
  RSDP  000e4500     24  v02 U-BOOT
  RSDT  000e4530     34  v01 U-BOOT U-BOOTBL 20220401 INTL 0
  XSDT  000e45e0     44  v01 U-BOOT U-BOOTBL 20220401 INTL 0
  CSRT  000e53a0     58  v00 U-BOOT U-BOOTBL 20220401 INTL 0
  MCFG  000e5520     3c  v01 U-BOOT U-BOOTBL 20220401 INTL 0
  SPCR  000e5560     50  v02 U-BOOT U-BOOTBL 20220401 INTL 0
  APIC  000e55b0     48  v02 U-BOOT U-BOOTBL 20220401 INTL 0

As a result Linux kernel can't find mandatory tables and fails
to boot.

Hence, revert it for good.

This reverts commit 379d3c1fd6.

BugLink: https://lore.kernel.org/all/20220131225930.GJ7515@bill-the-cat/
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2022-03-31 08:27:52 -04:00
Simon Glass
aafb31fc95 acpi: Move acpi_write_tables() to a generic header
This function is used by both x86 and sandbox. Put it in a common header
file.

Signed-off-by: Simon Glass <sjg@chromium.org>
2022-02-11 11:29:23 -05:00
Moritz Fischer
058fb9f5ff acpi: Move MCFG implementation to common lib
MCFG tables are used on multiple arches. Move to common ACPI lib.

Cc: Simon Glass <sjg@chromium.org>
Signed-off-by: Moritz Fischer <moritzf@google.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Use sizeof(*mcfg) instead of sizeof(*header)
Signed-off-by: Simon Glass <sjg@chromium.org>
2022-02-09 12:30:13 -07:00
Simon Glass
78031ad431 x86: acpi: Update acpi_fill_csrt() to use acpi_ctx
Update this function to the newer style, so we can avoid passing and
returning an address through this function.

Also move this function out of the x86 code so it can be used by other
archs.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2022-01-25 11:44:36 -07:00
Simon Glass
379d3c1fd6 x86: Move FACP table into separate functions
Each board has its own way of creating this table. Rather than calling the
acpi_create_fadt() function for each one from a common acpi_write_fadt()
function, just move the writer into the board-specific code.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2022-01-25 11:44:36 -07:00
Simon Glass
383bf1bc9e acpi: Move acpi_fill_header() to the generic header
This function is not x86-specific so move it into the common header file.

Signed-off-by: Simon Glass <sjg@chromium.org>
2022-01-25 11:44:36 -07:00
Heinrich Schuchardt
185f812c41 doc: replace @return by Return:
Sphinx expects Return: and not @return to indicate a return value.

find . -name '*.c' -exec \
sed -i 's/^\(\s\)\*\(\s*\)@return\(\s\)/\1*\2Return:\3/' {} \;

find . -name '*.h' -exec \
sed -i 's/^\(\s\)\*\(\s*\)@return\(\s\)/\1*\2Return:\3/' {} \;

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
2022-01-19 18:11:34 +01:00
Simon Glass
401d1c4f5d common: Drop asm/global_data.h from common header
Move this out of the common header and include it only where needed.  In
a number of cases this requires adding "struct udevice;" to avoid adding
another large header or in other cases replacing / adding missing header
files that had been pulled in, very indirectly.   Finally, we have a few
cases where we did not need to include <asm/global_data.h> at all, so
remove that include.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Rini <trini@konsulko.com>
2021-02-02 15:33:42 -05:00
Simon Glass
26c3d3d7d5 x86: Add a header guard to asm/acpi_table.h
This file cannot currently be included in ASL files. Add a header guard
to permit this.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-09-25 11:27:22 +08:00
Simon Glass
540f0bae9b x86: acpi: Add support for additional Intel tables
Apollo Lake needs to generate a few more table types used on Intel SoCs.
Add support for these into the x86 ACPI code.

Signed-off-by: Simon Glass <sjg@chromium.org>
2020-09-25 11:27:19 +08:00
Simon Glass
9b3e6d4c1f x86: acpi: Add common Intel ACPI tables
Add various tables that are common to Intel CPUs. These functions can be
used by arch-specific CPU code.

Signed-off-by: Simon Glass <sjg@chromium.org>
2020-09-25 11:27:18 +08:00
Simon Glass
f37979e7b7 x86: acpi: Support generation of the DBG2 table
Add an implementation of the DBG2 (Debug Port Table 2) ACPI table.
Adjust one of the header includes to be in the correct order, before
adding more.

Note that the DBG2 table is generic but the PCI UART is x86-specific at
present since it assumes an ns16550 UART. It can be generalised later
if necessary.

Signed-off-by: Simon Glass <sjg@chromium.org>
2020-09-25 11:27:17 +08:00
Simon Glass
d2628984b7 x86: acpi: Support generation of the HPET table
Add an implementation of the HPET (High Precision Event Timer) ACPI
table. Since this is x86-specific, put it in an x86-specific file

Signed-off-by: Simon Glass <sjg@chromium.org>
2020-09-25 11:27:17 +08:00
Simon Glass
8d7ff12e63 acpi: Allow creating the GNVS to fail
In some cases an internal error may prevent this from working. Update the
function return value and report the error. At present the API for writing
tables does not easily support reporting errors, but once it is fully
updated to use a context pointer, this will be easier.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
2020-07-17 14:32:24 +08:00
Simon Glass
776cc20194 x86: Move acpi_table header to main include/ directory
This file is potentially useful to other architectures saddled with ACPI
so move most of its contents to a common location.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
2020-04-16 14:36:28 +08:00
Andy Shevchenko
19b6e1ba8c x86: acpi: Annotate struct acpi_table_header with __packed
GCC 9.2 starts complaining about possible pointer misalignment of
pointers to the unpacked (alignment=4) structures in the packed
(alignment=1) ones:

  CC      arch/x86/cpu/tangier/acpi.o
arch/x86/cpu/tangier/acpi.c: In function ‘acpi_create_fadt’:
arch/x86/cpu/tangier/acpi.c:22:37: warning: taking address of packed
member of ‘struct acpi_fadt’ may result in an unaligned pointer value
[-Waddress-of-packed-member]
  22 |  struct acpi_table_header *header = &(fadt->header);

  CC      arch/x86/lib/acpi_table.o
arch/x86/lib/acpi_table.c: In function ‘acpi_create_spcr’:
arch/x86/lib/acpi_table.c:366:37: warning: taking address of packed
member of ‘struct acpi_spcr’ may result in an unaligned pointer value
[-Waddress-of-packed-member]
  366 |  struct acpi_table_header *header = &(spcr->header);

Fix the potential issues by annotating embedded structures with
__packed even though they are packed naturally.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
[bmeng: add GCC version number in the commit message]
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
2019-09-10 16:17:55 +08:00
Andy Shevchenko
ddd2a4244c x86: acpi: Introduce a stub to generate CSRT
Here is a stub function that generates an empty CSRT. If the target platform
provides acpi_fill_csrt() function, it will be used to populate the table.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2019-08-09 22:24:02 +08:00
Andy Shevchenko
eef3007945 x86: acpi: Add CSRT description
Add CSRT [1] description as it provided in Linux kernel.

[1]: http://www.uefi.org/sites/default/files/resources/CSRT%20v2.pdf

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2019-08-09 22:24:02 +08:00
Andy Shevchenko
b288cd9600 x86: acpi: Generate SPCR table
Microsoft specifies a SPCR (Serial Port Console Redirection Table) [1].
Let's provide it in U-Boot.

[1]: https://docs.microsoft.com/en-us/windows-hardware/drivers/serports/serial-port-console-redirection-table

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2018-12-05 07:23:16 -07:00
Andy Shevchenko
f3275aa4a1 x86: acpi: Add SPCR table description
Add SPCR table description as it provided in Linux kernel.

Port subtype for ACPI_DBG2_SERIAL_PORT is used as an interface type in SPCR.
Thus, provide a set of definitions to be utilized later.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2018-12-05 07:23:16 -07:00
Bin Meng
05855fd31a x86: acpi: Prevent acpi_table.h from being included more than once
The wrapper #ifndef is currently missing in acpi_table.h. Add it to
prevent it from being included multiple times.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2018-07-20 09:33:22 +08:00
Bin Meng
a0609a8d19 x86: acpi: Move APIs unrelated to ACPI tables generation to a separate library
acpi_find_fadt(), acpi_find_wakeup_vector() and enter_acpi_mode()
are something unrelated to ACPI tables generation. Move these to
a separate library.

This also fixes several style issues reported by checkpatch in the
original codes.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2018-07-20 09:33:22 +08:00
Tom Rini
83d290c56f SPDX: Convert all of our single license tags to Linux Kernel style
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>
2018-05-07 09:34:12 -04:00
Bin Meng
45410da714 x86: acpi: Use an API to get the ACPI RSDP table address
At present the acpi_rsdp_addr variable is directly referenced in
setup_zimage(). This changes to use an API for better encapsulation
and extension.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2018-01-30 22:34:37 +08:00
Andy Shevchenko
ace7762b28 x86: acpi: Export acpi_fill_mcfg() with __weak attribute
Some platforms might require different approach when filling memory
mappings configuration table.

Allow them to override the common method.

At the same time export acpi_create_mcfg_mmconfig().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2017-07-30 10:30:25 +08:00
Andy Shevchenko
2dcbef6f6c x86: acpi: Name fields in FADT in accordance with specification
ACPI specification defines FADT fields marked as reserved in U-Boot.

Name these fields in accordance with ACPI specification.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2017-07-30 10:30:25 +08:00
Bin Meng
0f4e25887d x86: acpi: Refactor acpi_resume()
To do something more in acpi_resume() like turning on ACPI mode,
we need locate ACPI FADT table pointer first. But currently this
is done in acpi_find_wakeup_vector().

This changes acpi_resume() signature to accept ACPI FADT pointer
as the parameter. A new API acpi_find_fadt() is introduced, and
acpi_find_wakeup_vector() is updated to use FADT pointer as the
parameter as well.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Stefan Roese <sr@denx.de>
2017-05-17 17:11:46 +08:00
Bin Meng
995727850f x86: acpi: Make enter_acpi_mode() public
enter_acpi_mode() is useful on other boot path like S3 resume, so
make it public.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Stefan Roese <sr@denx.de>
2017-05-17 17:11:46 +08:00
Bin Meng
e76bf38f18 x86: acpi: Add one API to find OS wakeup vector
This adds one API acpi_find_wakeup_vector() to locate OS wakeup
vector from the ACPI FACS table, to be used in the S3 boot path.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Stefan Roese <sr@denx.de>
2017-05-17 17:11:46 +08:00
Simon Glass
42fd8c19b5 x86: Use unsigned long for address in table generation
We should use unsigned long rather than u32 for addresses. Update this so
that the table-generation code builds correctly on 64-bit machines.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2017-02-06 11:38:46 +08:00
Bin Meng
79c2c257cf x86: acpi: Pack global NVS into ACPI table
Now that platform-specific ACPI global NVS is added, pack it into
ACPI table and get its address fixed up.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: George McCollister <george.mccollister@gmail.com>
Tested-by: George McCollister <george.mccollister@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2016-07-12 13:46:01 +08:00
Bin Meng
6aef68dc36 x86: acpi: Switch to ACPI mode by ourselves instead of requested by OSPM
Per ACPI spec, during ACPI OS initialization, OSPM can determine
that the ACPI hardware registers are owned by SMI (by way of the
SCI_EN bit in the PM1_CNT register), in which case the ACPI OS
issues the ACPI_ENABLE command to the SMI_CMD port. The SCI_EN bit
effectively tracks the ownership of the ACPI hardware registers.

However since U-Boot does not support SMI, we report all 3 fields
in FADT (SMI_CMD, ACPI_ENABLE, ACPI_DISABLE) as zero, by following
the spec who says: these fields are reserved and must be zero on
system that does not support System Management mode.

U-Boot seems to behave in a correct way that the ACPI spec allows,
at least Linux does not complain, but apparently Windows does not
think so. During Windows bring up debugging, it is observed that
even these 3 fields are zero, Windows are still trying to issue SMI
with hardcoded SMI port address and commands, and expecting SCI_EN
to be changed by the firmware. Eventually Windows gives us a BSOD
(Blue Screen of Death) saying ACPI_BIOS_ERROR and refuses to start.

To fix this, turn on the SCI_EN bit by ourselves. With this patch,
now U-Boot can install and boot Windows 8.1/10 successfully with
the help of SeaBIOS using legacy interface (non-UEFI mode).

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2016-05-23 15:18:00 +08:00
Bin Meng
fc4f5cccd8 x86: acpi: Return table length in acpi_create_madt_lapics()
Like other MADT table write routines, make acpi_create_madt_lapics()
return how many bytes it has written instead of the table end addr.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2016-05-23 15:18:00 +08:00
Bin Meng
7e6343ef94 x86: acpi: Clean up table header revisions
The comment of initializing table header revision says:

    /* ACPI 1.0/2.0: 1, ACPI 3.0: 2, ACPI 4.0: 3 */

which might mislead it may increase per ACPI spec revision.
However this is not the case. It's actually a fixed number
as defined in ACPI spec, and in the laest ACPI spec 6.1,
some table header revisions are still 1. Clean these up.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2016-05-23 15:18:00 +08:00
Bin Meng
7e79a6bc2e x86: acpi: Use u32 in table write routines
Use u32 instead of unsigned long in the table write routines, as
other routines do.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2016-05-23 15:18:00 +08:00
Bin Meng
ab5efd576c x86: acpi: Adjust order in acpi_table.c
Rearrange the routine order a little bit, to follow the order
in which ACPI table is defined in acpi_table.h.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>

Reviewed-by: Stefan Roese <sr@denx.de>
Tested-by: Stefan Roese <sr@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
2016-05-23 15:18:00 +08:00
Bin Meng
dfbb18bcf6 x86: acpi: Change fill_header()
Rename fill_header() to acpi_fill_header() for consistency.
Change its signature to remove the 'length' parameter and
make it a public API.

Also remove the unnecessary include files, and improve the
AmlCode[] comment a little bit.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Tested-by: Stefan Roese <sr@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
2016-05-23 15:18:00 +08:00
Bin Meng
cea91319c2 x86: acpi: Remove acpi_create_ssdt_generator()
This acpi_create_ssdt_generator() currently does nothing.
Remove this for now.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Tested-by: Stefan Roese <sr@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
2016-05-23 15:18:00 +08:00
Bin Meng
728c4afc39 x86: acpi: Reorder code in acpi_table.h
Reorder the ACPI tables appearance by following the order:
RSDP, RSDT, XSDT, FADT, FACS, MADT, MCFG. And adjust the
table flag defines accordingly.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Tested-by: Stefan Roese <sr@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
2016-05-23 15:18:00 +08:00
Bin Meng
8a8c035255 x86: acpi: Various changes to acpi_table.h
- Use "U-BOOT" and "U-BOOTBL" for the OEM ID and OEM table ID.
- Do not typedef acpi_header_t, instead use struct acpi_table_hader.
- Use a shorter name aslc_id and aslc-revision.
- Change MCFG base address to use 32-bit value pairs (_l and _h).
- Apply ACPI_APIC_ prefix to MADT APIC type macros and make
  their names to be more readable.
- Apply __packed to struct acpi_madt_irqoverride and struct
  acpi_madt_lapic_nmi tables, as they are not naturally aligned
  by the compiler which leads to wrong sizeof(struct).
- Rename model to res1 as it is reserved after ACPI spec 1.0.
- Apply ACPI_ prefix to the PM profile macros and change them
  to enum.
- Add ospm_flags to FACS structure which is defined since ACPI 4.0.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Tested-by: Stefan Roese <sr@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
2016-05-23 15:18:00 +08:00
Bin Meng
f4446629c9 x86: acpi: Remove unused codes
- Remove #include <> header files.
- Remove APM_CNT register defines, which should not be here as
  they are SMI related.
- Remove MP_IRQ_ defines as they are duplicates of the same ones
  in asm/mpspec.h.
- Remove ACTL register defines, which should not be here as they
  are chipset specific.
- Remove functional fixed hardware defines, which are not used.
- Remove dev_scope related defines, which are not used.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Tested-by: Stefan Roese <sr@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
2016-05-23 15:18:00 +08:00
Bin Meng
358bb3ff5b x86: Change write_acpi_tables() signature a little bit
Change the parameter and return value of write_acpi_tables() to u32
to conform with other table write routines.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2016-03-17 10:27:22 +08:00
Saket Sinha
867bcb63e7 x86: Generate a valid ACPI table
Implement write_acpi_table() to create a minimal working ACPI table.
This includes writing FACS, XSDT, RSDP, FADT, MCFG, MADT, DSDT & SSDT
ACPI table entries.

Use a Kconfig option GENERATE_ACPI_TABLE to tell U-Boot whether we need
actually write the APCI table just like we did for PIRQ routing, MP table
and SFI tables. With ACPI table existence, linux kernel gets control of
power management, thermal management, configuration management and
monitoring in hardware.

Signed-off-by: Saket Sinha <saket.sinha89@gmail.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tidied up whitespace and aligned some tabs:
Signed-off-by: Simon Glass <sjg@chromium.org>
2015-08-26 07:54:13 -07:00