mirror of
https://github.com/brain-hackers/u-boot-brain
synced 2024-08-27 12:28:52 +09:00
![Simon Glass](/assets/img/avatar_default.png)
It is useful to be able to load U-Boot onto a board even if is it already running EFI. This can allow access to the U-Boot command interface, flexible booting options and easier development. The easiest way to do this is to build U-Boot as a binary blob and have an EFI stub copy it into RAM. Add support for this feature, targeting 32-bit initially. Also add a way to detect when U-Boot has been loaded via a stub. This goes in common.h since it needs to be widely available so that we avoid redoing initialisation that should be skipped. Signed-off-by: Simon Glass <sjg@chromium.org> Improvements to how the payload is built: Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Bin Meng <bmeng.cn@gmail.com>
55 lines
1.7 KiB
Plaintext
55 lines
1.7 KiB
Plaintext
config EFI
|
|
bool "Support running U-Boot from EFI"
|
|
depends on X86
|
|
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
|