Implement SDRAM init using the Memory Reference Code (mrc.bin) provided in
the board directory and the SDRAM SPD information in the device tree. This
also needs the Intel Management Engine (me.bin) to work. Binary blobs
everywhere: so far we have MRC, ME and microcode.
SDRAM init works by setting up various parameters and calling the MRC. This
in turn does some sort of magic to work out how much memory there is and
the timing parameters to use. It also sets up the DRAM controllers. When
the MRC returns, we use the information it provides to map out the
available memory in U-Boot.
U-Boot normally moves itself to the top of RAM. On x86 the RAM is not
generally contiguous, and anyway some RAM may be above 4GB which doesn't
work in 32-bit mode. So we relocate to the top of the largest block of
RAM we can find below 4GB. Memory above 4GB is accessible with special
functions (see physmem).
It would be possible to build U-Boot in 64-bit mode but this wouldn't
necessarily provide any more memory, since the largest block is often below
4GB. Anyway U-Boot doesn't need huge amounts of memory - even a very large
ramdisk seldom exceeds 100-200MB. U-Boot has support for booting 64-bit
kernels directly so this does not pose a limitation in that area. Also there
are probably parts of U-Boot that will not work correctly in 64-bit mode.
The MRC is one.
There is some work remaining in this area. Since memory init is very slow
(over 500ms) it is possible to save the parameters in SPI flash to speed it
up next time. Suspend/resume support is not fully implemented, or at least
it is not efficient.
With this patch, link boots to a prompt.
Signed-off-by: Simon Glass <sjg@chromium.org>
The local advanced programmable interrupt controller is not used much in
U-Boot but we do need to set it up. Add basic support for this, which will
be extended as needed.
Signed-off-by: Simon Glass <sjg@chromium.org>
When not relying on Coreboot for GPIO init the GPIOs must be set up
correctly. This is currently done statically through a rather ugly method.
As the GPIOs are figured out they can be moved to the device tree and set
up as needed rather than all at the start.
In this implementation, board files should call ich_gpio_set_gpio_map()
before the GPIO driver is used in order to provide the GPIO information.
We use the early PCI interface so that this driver can now be used before
relocation.
Signed-off-by: Simon Glass <sjg@chromium.org>
Add two microcode updates that are provided for this CPU. The updates
have been converted to a device tree form.
Note: SPDX submission has been done. If this license is approved I will
convert the files to use SPDX.
Signed-off-by: Simon Glass <sjg@chromium.org>
The built-in self test value should be checked before we continue booting.
Refuse to continue if there is something wrong.
Signed-off-by: Simon Glass <sjg@chromium.org>
It is convenient to be able to adjust MSRs with a structure that splits the
two 32-bit halves into separate fields, as they are often dealt with
separately. Add a few functions to support this.
Signed-off-by: Simon Glass <sjg@chromium.org>
There is no need to explicitly write 'arch-coreboot' when including headers,
as when the arch directory points to coreboot the correct files will be
used.
Signed-off-by: Simon Glass <sjg@chromium.org>
The PCH (Platform Controller Hub) includes an LPC (Low Pin Count) device
which provides a serial port. This is accessible on Chromebooks, so enable
it early in the boot process.
Signed-off-by: Simon Glass <sjg@chromium.org>
Add simple PCI access routines for x86 which permit use before relocation.
The normal PCI stack is still used, but for pre-relocation use there can
only ever be a single hose. After relocation, fall back to the normal
access, although even then on x86 machines there is normally only a single
PCI bus.
Signed-off-by: Simon Glass <sjg@chromium.org>
Add support for using PCI before SDRAM is available, using early malloc()
and global_data.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
We want access PCI earlier in the init sequence, so refactor the code so
that it does not require use of a BSS variable to work. This will allow us
to use early malloc() to store information about a PCI hose.
Common PCI code moves to arch/x86/cpu/pci.c and a new
board_pci_setup_hose() function is provided by boards to set up the (single)
hose used by that board.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Add support for CAR so that we have memory to use prior to DRAM init.
On link there is a total of 128KB of CAR available, although some is
used for the memory reference code.
Signed-off-by: Simon Glass <sjg@chromium.org>
On x86 it is common to use 'post codes' which are 8-bit hex values emitted
from the code and visible to the user. Traditionally two 7-segment displays
were made available on the motherboard to show the last post code that was
emitted. This allows diagnosis of a boot problem since it is possible to
see where the code got to before it died.
On modern hardware these codes are not normally visible. On Chromebooks
they are displayed by the Embedded Controller (EC), so it is useful to emit
them. We must enable this feature for the EC to see the codes, so add an
option for this.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
On x86 machines U-Boot needs to be added to a large ROM image which is
then flashed onto the target board. The ROM has a particular format so it
makes sense for U-Boot to build this image automatically. Unfortunately
it relies on binary blobs so we cannot require this for the default
build as yet.
Create a u-boot.rom output file for this purpose.
Signed-off-by: Simon Glass <sjg@chromium.org>
This board is a 'bare' version of the existing 'link 'board. It does not
require coreboot to run, but is intended to start directly from the reset
vector.
This initial commit has place holders for a wide range of features. These
will be added in follow-on patches and series. So far it cannot be booted
as there is no ROM image produced, but it does build without errors.
Signed-off-by: Simon Glass <sjg@chromium.org>
Unfortunately MSR_FSB_FREQ is not available on this CPU, and the PIT method
seems to take up to 50ms which is much too long.
For this CPU we know the frequency, so add another special case for now.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
The references of CONFIG_SYS_COREBOOT in arch/x86/cpu/coreboot/Makefile
are redundant because the build system descends into the directory
only when CONFIG_SYS_COREBOOT is defined.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Simon Glass <sjg@chromium.org>
Acked-by: Simon Glass <sjg@chromium.org>
This implementation has a 'cpu' prefix and returns a pointer to the string,
avoiding the need for copying.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Add a function to get the stack pointer and another to halt the CPU.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Return the saved TSC frequency in get_tbclk_mhz().
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
Use the same way that Linux does for quick TSC calibration via PIT
when calibration via MSR fails.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
Using MSR_PLATFORM_INFO (0xCE) to calibrate TSR will cause #GP on
processors which do not have this MSR. Instead only doing the MSR
calibration for known/supported CPUs.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
The CPU identification happens in x86_cpu_init_f() and corresponding
fields are saved in the global data for later use.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
The built in self test value is available in register eax on start-up. Save
it so that it can be accessed later. Unfortunately we must wait until the
global_data is available before we can do this, so there is a little bit of
shuffling to keep it around.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Some functions are missing prototypes. Fix those that are specific to x86.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Instead of an x86-specific cpu_init_f() function, use the normal U-Boot one
for this purpose. Also remove a useless/misleading comment.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Instead of having an x86-specific DRAM init function, adjust things so we
can use the normal one.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
This code is a little muddled, so tidy it up. Make sure that we put the
GDT in the right place and set it up properly.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
We should invalidate the TLB right at the start to ensure that we don't get
false address translations even though paging is disabled.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
This allows a board to do very early init, but no boards need to do this.
We may as well drop this feature.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
This was missed when the real mode support was dropped. Remove it.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
The boot_zimage() function is badly named it can also boot a raw kernel.
Rename it, and try to avoid pointers for memory addresses as it involves
lots of casting.
Signed-off-by: Simon Glass <sjg@chromium.org>
Add code to jump to a 64-bit Linux kernel. We need to set up a flat page
table structure, a new GDT and then go through a few hoops in the right
order.
Signed-off-by: Simon Glass <sjg@chromium.org>
There's a definition in stdint.h (provided by gcc) which will be more correct
if available.
Define CONFIG_USE_STDINT to use this feature, or USE_STDINT=1 on the 'make'
commmand.
This adjusts the settings for x86 and sandbox, with both have 64-bit options.
Signed-off-by: Gabe Black <gabeblack@google.com>
Reviewed-by: Gabe Black <gabeblack@chromium.org>
Tested-by: Gabe Black <gabeblack@chromium.org>
Reviewed-by: Bill Richardson <wfrichar@google.com>
Rewritten to be an option, since stdint.h is often available only in glibc.
Changed to preserve a clear boundary between stdint and non-stdint
Signed-off-by: Simon Glass <sjg@chromium.org>
Add more information so that U-Boot can find the address of the serial port.
Also fix the reg-shift value.
Signed-off-by: Simon Glass <sjg@chromium.org>
This code doesn't follow the normal approach of having its arch-specific
definitions in an arch-specific directory. Add a new arch-specific file
and make use of it.
Signed-off-by: Simon Glass <sjg@chromium.org>
To permit information to be passed from the early U-Boot code to
board_init_f() we cannot zero the global_data in board_init_f(). Instead
zero it in the start-up code.
Signed-off-by: Simon Glass <sjg@chromium.org>
This code generates warnings with recent gcc versions. We really don't need
the clobber specification, so just drop it.
Signed-off-by: Simon Glass <sjg@chromium.org>
The private libgcc is supported only on ARM, MIPS, PowerPC, SH, x86.
Those architectures should "select" HAVE_PRIVATE_LIBGCC and
CONFIG_USE_PRIVATE_LIBGCC should depend on it.
Currently, this option is enabled on Tegra boards and x86 architecture.
Move the definition from header files to Kconfig.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Tested-by: Simon Glass <sjg@chromium.org>
Acked-by: Simon Glass <sjg@chromium.org>
Cc: Stephen Warren <swarren@nvidia.com>
Cc: Tom Warren <twarren@nvidia.com>
The motivation of this commit is to change CONFIG_USE_PRIVATE_LIBGCC
to a boolean macro so we can move it to Kconfig.
In the current implementation, there are two forms of syntax
for this macro:
- CONFIG_USE_PRIVATE_LIBGCC=y
- CONFIG_USE_PRIVATE_LIBGCC=path/to/private/libgcc
The latter is only used by x86 architecture.
With a little bit refactoring, it can be converted to the former.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Tested-by: Simon Glass <sjg@chromium.org>
Acked-by: Simon Glass <sjg@chromium.org>
When building U-Boot with CONFIG_X86_RESET_VECTOR, the linking
process misses the resetvec.o and start16.o so it cannot generate
the rom version of U-Boot. The arch/x86/cpu/Makefile is updated to
pull them into the final linking process.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
The x86 bootm code is quite special, and geared to zimage. Adjust it
to support device tree and make it more like the ARM code, with
separate bootm stages and functions for each stage.
Create a function announce_and_cleanup() to handle printing the
"Starting kernel ..." message and put it in bootm so it is in one
place and can be used by any loading code. Also move the
board_final_cleanup() function into bootm.
Signed-off-by: Simon Glass <sjg@chromium.org>
These options are used by the image code. To allow us to use the generic
code more easily, define these for x86.
Signed-off-by: Simon Glass <sjg@chromium.org>
Now the types of CONFIG_SYS_{ARCH, CPU, SOC, VENDOR, BOARD, CONFIG_NAME}
are specified in arch/Kconfig.
We can delete the ones in arch and board Kconfig files.
This commit can be easily reproduced by the following command:
find . -name Kconfig -a ! -path ./arch/Kconfig | xargs sed -i -e '
/config[[:space:]]SYS_\(ARCH\|CPU\|SOC\|\VENDOR\|BOARD\|CONFIG_NAME\)/ {
N
s/\n[[:space:]]*string//
}
'
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
This commit adds:
- arch/${ARCH}/Kconfig
provide a menu to select target boards
- board/${VENDOR}/${BOARD}/Kconfig or board/${BOARD}/Kconfig
set CONFIG macros to the appropriate values for each board
- configs/${TARGET_BOARD}_defconfig
default setting of each board
(This commit was automatically generated by a conversion script
based on boards.cfg)
In Linux Kernel, defconfig files are located under
arch/${ARCH}/configs/ directory.
It works in Linux Kernel since ARCH is always given from the
command line for cross compile.
But in U-Boot, ARCH is not given from the command line.
Which means we cannot know ARCH until the board configuration is done.
That is why all the "*_defconfig" files should be gathered into a
single directory ./configs/.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: Simon Glass <sjg@chromium.org>
At present stdio device functions do not get any clue as to which stdio
device is being acted on. Some implementations go to great lengths to work
around this, such as defining a whole separate set of functions for each
possible device.
For driver model we need to associate a stdio_dev with a device. It doesn't
seem possible to continue with this work-around approach.
Instead, add a stdio_dev pointer to each of the stdio member functions.
Note: The serial drivers have the same problem, but it is not strictly
necessary to fix that to get driver model running. Also, if we convert
serial over to driver model the problem will go away.
Code size increases by 244 bytes for Thumb2 and 428 for PowerPC.
22: stdio: Pass device pointer to stdio methods
arm: (for 2/2 boards) all +244.0 bss -4.0 text +248.0
powerpc: (for 1/1 boards) all +428.0 text +428.0
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Marek Vasut <marex@denx.de>
Reviewed-by: Marek Vasut <marex@denx.de>
There is no point in setting a structure's memory to NULL when it has
already been zeroed with memset().
Also, there is no need to create a stub function for stdio to call - if the
function is NULL it will not be called.
This is a clean-up, with no change in functionality.
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Marek Vasut <marex@denx.de>
Until now building the x86 arch boards required 32-bit toolchain. As
many x86_64 toolchains come with 32-bit support (multilib) that's a
good idea to enable build with such toolchains.
The change required was to specify the usage of 32-bit explicitly to
the compiler and the linker (-m32 and -m elf_i386 flags) and locate
the right libgcc path.
Signed-off-by: Vasili Galka <vvv444@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
Linux supports this, and if we are to have compatible device tree files,
U-Boot should also.
Avoid giving the device tree files access to U-Boot's include/ directory.
Only include/dt-bindings is accessible.
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
U-Boot has supported two kinds of asm-offsets.h.
One is generic for all architectures and its source is located at
./lib/asm-offsets.c.
The other is SoC specific and its source is under SoC directory.
The problem here is that only boards with SoC directory can use
the asm-offsets infrastructure.
Putting asm-offsets.c right under CPU directory does not work.
Now a new demand is coming. PowerPC folks want to use asm-offsets.
But no PowerPC boards have SoC directory.
It seems inconsistent that some boards add asm-offsets.c to SoC
directoreis and some to CPU directories.
It looks more reasonable to put asm-offsets.c under arch/$(ARCH)/lib.
This commit merges asm-offsets.c under SoC directories into
arch/$(ARCH)/lib/asm-offsets.c.
By the way, I doubt the necessity of some entries in asm-offsets.c.
I am leaving refactoring to the board maintainers.
Please check "TODO" in the comment blocks in
arch/{arm,nds32}/lib/asm-offsets.c.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Yuantian Tang <Yuantian.Tang@freescale.com>
Before this commit, USE_PRIVATE_LIBGCC was defined in
arch-specific config.mk and referenced in
arch/$(ARCH)/lib/Makefile.
We are not happy about parsing config.mk again and again.
We have to keep the same behavior with a different way.
By adding "CONFIG_" prefix, this macro appears
in include/autoconf.mk, include/spl-autoconf.mk.
(And treating USE_PRIVATE_LIBGCC as CONFIG macro
is reasonable enough.)
Tegra SoC family defined USE_PRIVATE_LIBGCC as "yes"
in arch/arm/cpu/arm720t/tegra*/config.mk,
whereas did not define it in arch/arm/cpu/armv7/tegra*/config.mk.
It means Tegra enables PRIVATE_LIBGCC only for SPL.
We can describe the same behavior by adding
#ifdef CONFIG_SPL_BUILD
# define CONFIG_USE_PRIVATE_LIBGCC
#endif
to include/configs/tegra-common.h.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Tom Warren <twarren@nvidia.com>
Cc: Simon Glass <sjg@chromium.org>
Acked-by: Stephen Warren <swarren@nvidia.com>
-Wstrict-prototypes, -ffreestanding, -fno-stack-protector
are defined at the top Makefile for all architectures.
Do not define them twice for x86.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Simon Glass <sjg@chromium.org>
Acked-by: Simon Glass <sjg@chromium.org>
It is convenient to have all device trees on the same SoC compiled.
It allows for later easy repackaging without the need to re-run
the make file.
- Build device trees with the same SoC under arch/$(ARCH)/dts
- Copy the one specified by CONFIG_DEFAULT_DEVICE_TREE or
DEVICE_TREE=... to dts/dt.dtb
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Unlike Linux Kernel, U-Boot historically had *.dts files under
board/$(VENDOR)/dts/ and *.dtsi files under arch/$(ARCH)/dts/.
I think arch/$(ARCH)/dts dicretory is a better location
to store both *.dts and *.dtsi files.
For example, before this commit, board/xilinx/dts directory
had both Microblaze dts (microblaze-generic.dts) and
ARM dts (zynq-*.dts), which are totally unrelated.
This commit moves *.dts to arch/$(ARCH)/dts/ directories,
allowing us to describe nicely mutiple DTBs generation in the next commit.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Useful rules in scripts/Makefile.lib allows us to easily
generate a device tree blob and wrap it in assembly code.
We do not need to parse a linker script to get output format and arch.
This commit deletes ./u-boot.dtb since it is a copy of dts/dt.dtb.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
This commit changes the working directory
where the build process occurs.
Before this commit, build process occurred under the source
tree for both in-tree and out-of-tree build.
That's why we needed to add $(obj) prefix to all generated
files in makefiles like follows:
$(obj)u-boot.bin: $(obj)u-boot
Here, $(obj) is empty for in-tree build, whereas it points
to the output directory for out-of-tree build.
And our old build system changes the current working directory
with "make -C <sub-dir>" syntax when descending into the
sub-directories.
On the other hand, Kbuild uses a different idea
to handle out-of-tree build and directory descending.
The build process of Kbuild always occurs under the output tree.
When "O=dir/to/store/output/files" is given, the build system
changes the current working directory to that directory and
restarts the make.
Kbuild uses "make -f $(srctree)/scripts/Makefile.build obj=<sub-dir>"
syntax for descending into sub-directories.
(We can write it like "make $(obj)=<sub-dir>" with a shorthand.)
This means the current working directory is always the top
of the output directory.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Tested-by: Gerhard Sittig <gsi@denx.de>
Now that nothing uses CONFIG_ARCH_DEVICE_TREE, stop defining it.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>
MAKEALL is fine for ppc4xx and mpc85xx.
Run checks were done on our controlcenterd hardware.
Signed-off-by: Dirk Eibach <dirk.eibach@gdsys.cc>
Signed-off-by: Andy Fleming <afleming@freescale.com>
The OS function is now always called with the PREP stage. Adjust the
remaining bootm OS functions to deal with this correctly.
Signed-off-by: Simon Glass <sjg@chromium.org>
Some changes are needed to x86 timer functions to support tracing. Add
these so that the feature works correctly.
Signed-off-by: Simon Glass <sjg@chromium.org>
Coreboot provides a lot of useful timing information. Provide a facility
to add this to bootstage on start-up.
Signed-off-by: Simon Glass <sjg@chromium.org>
While we don't want PCAT timers for timing, we want timer 2 so that we can
still make a beep. Re-purpose the PCAT driver for this, and enable it in
coreboot.
Signed-off-by: Simon Glass <sjg@chromium.org>
This is no longer used since we prefer the more accurate TSC timer, so
remove the dead code.
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Graeme Russ <graeme.russ@gmail.com>
Tidy up some old broken and unneeded implementations. These are not used
by coreboot or anything else now.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Gabe Black <gabeblack@chromium.org>
Reviewed-by: Michael Spang <spang@chromium.org>
Reviewed-by: Vadim Bendebury <vbendeb@chromium.org>
Acked-by: Graeme Russ <graeme.russ@gmail.com>
This timer runs at a rate that can be calculated, well over 100MHz. It is
ideal for accurate timing and does not need interrupt servicing.
Tidy up some old broken and unneeded implementations at the same time.
To provide a consistent view of boot time, we use the same time
base as coreboot. Use the base timestamp supplied by coreboot
as U-Boot's base time.
Signed-off-by: Simon Glass <sjg@chromium.org>base
Signed-off-by: Simon Glass <sjg@chromium.org>
The 'Starting linux' message appears twice in the code, but both call
through the same place. Unify these and add calls to bootstage to
mark the occasion.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Michael Spang <spang@chromium.org>
Acked-by: Graeme Russ <graeme.russ@gmail.com>
panic_puts() can be called in early boot to display a message. It might
help with early debugging.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Wai-Hong Tam <waihong@chromium.org>
Several files use the global_data pointer without declaring it. This works
because the declaration is currently a NOP. But still it is better to
fix this so that x86 lines up with other archs.
Signed-off-by: Simon Glass <sjg@chromium.org>
