u-boot-brain/lib/efi/Kconfig
Simon Glass 77dd7c6854 x86: timer: use a timer base of 0
On x86 platforms the timer is reset to 0 when the SoC is reset. Having
this as the timer base is useful since it provides an indication of how
long it takes before U-Boot is running.

When U-Boot sets the timer base to something else, time is lost and we
no-longer have an accurate account of the time since reset. This
particularly affects bootstage.

Change the default to not read the timer base, leaving it at 0. Add an
option for when U-Boot is the secondary bootloader.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2019-12-15 11:44:09 +08:00

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config EFI
bool "Support running U-Boot from EFI"
depends on X86
imply X86_TSC_READ_BASE
help
U-Boot can be started from EFI on certain platforms. This allows
EFI to perform most of the system init and then jump to U-Boot for
final system boot. Another option is to run U-Boot as an EFI
application, with U-Boot using EFI's drivers instead of its own.
choice
prompt "Select EFI mode to use"
depends on X86 && EFI
config EFI_APP
bool "Support running as an EFI application"
help
Build U-Boot as an application which can be started from EFI. This
is useful for examining a platform in the early stages of porting
U-Boot to it. It allows only very basic functionality, such as a
command prompt and memory and I/O functions. Use 'reset' to return
to EFI.
config EFI_STUB
bool "Support running as an EFI payload"
endchoice
config EFI_RAM_SIZE
hex "Amount of EFI RAM for U-Boot"
depends on EFI_APP
default 0x2000000
help
Set the amount of EFI RAM which is claimed by U-Boot for its own
use. U-Boot allocates this from EFI on start-up (along with a few
other smaller amounts) and it can never be increased after that.
It is used as the RAM size in with U-Boot.
choice
prompt "EFI 32/64-bit selection"
depends on EFI_STUB
help
EFI does not support mixing 32-bit and 64-bit modes. This is a
significant problem because it means that you must build a stub with
the correct type for EFI to load it correctly. If you are using
32-bit EFI, select 32-bit here, else select 64-bit. Failure to do
this may produce no error message - it just won't start!
config EFI_STUB_32BIT
bool "Produce a stub for running with 32-bit EFI"
config EFI_STUB_64BIT
bool "Produce a stub for running with 64-bit EFI"
endchoice