efi: Add start-up library code
When running as an EFI application, U-Boot must request memory from EFI,
and provide access to the boot services U-Boot needs.
Add library code to perform these tasks. This includes efi_main() which is
the entry point from EFI. U-Boot is built as a shared library.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/lib/efi/Kconfig b/lib/efi/Kconfig
new file mode 100644
index 0000000..b23ba5b
--- /dev/null
+++ b/lib/efi/Kconfig
@@ -0,0 +1,33 @@
+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_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.
+
+endchoice