efi_loader: Add runtime services
After booting has finished, EFI allows firmware to still interact with the OS
using the "runtime services". These callbacks live in a separate address space,
since they are available long after U-Boot has been overwritten by the OS.
This patch adds enough framework for arbitrary code inside of U-Boot to become
a runtime service with the right section attributes set. For now, we don't make
use of it yet though.
We could maybe in the future map U-boot environment variables to EFI variables
here.
Signed-off-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/config.mk b/arch/arm/config.mk
index 8fa57ec..9af6c37 100644
--- a/arch/arm/config.mk
+++ b/arch/arm/config.mk
@@ -122,6 +122,10 @@
OBJCOPYFLAGS += -j .dtb.init.rodata
endif
+ifdef CONFIG_EFI_LOADER
+OBJCOPYFLAGS += -j .efi_runtime -j .efi_runtime_rel
+endif
+
ifneq ($(CONFIG_IMX_CONFIG),)
ifdef CONFIG_SPL
ifndef CONFIG_SPL_BUILD
diff --git a/arch/arm/cpu/armv8/u-boot.lds b/arch/arm/cpu/armv8/u-boot.lds
index 4c12222..fd15ad5 100644
--- a/arch/arm/cpu/armv8/u-boot.lds
+++ b/arch/arm/cpu/armv8/u-boot.lds
@@ -42,6 +42,22 @@
. = ALIGN(8);
+ .efi_runtime : {
+ __efi_runtime_start = .;
+ *(efi_runtime_text)
+ *(efi_runtime_data)
+ __efi_runtime_stop = .;
+ }
+
+ .efi_runtime_rel : {
+ __efi_runtime_rel_start = .;
+ *(.relaefi_runtime_text)
+ *(.relaefi_runtime_data)
+ __efi_runtime_rel_stop = .;
+ }
+
+ . = ALIGN(8);
+
.image_copy_end :
{
*(.__image_copy_end)
diff --git a/arch/arm/cpu/u-boot.lds b/arch/arm/cpu/u-boot.lds
index e148ab7..13aa4fa 100644
--- a/arch/arm/cpu/u-boot.lds
+++ b/arch/arm/cpu/u-boot.lds
@@ -90,6 +90,36 @@
. = ALIGN(4);
+ .__efi_runtime_start : {
+ *(.__efi_runtime_start)
+ }
+
+ .efi_runtime : {
+ *(efi_runtime_text)
+ *(efi_runtime_data)
+ }
+
+ .__efi_runtime_stop : {
+ *(.__efi_runtime_stop)
+ }
+
+ .efi_runtime_rel_start :
+ {
+ *(.__efi_runtime_rel_start)
+ }
+
+ .efi_runtime_rel : {
+ *(.relefi_runtime_text)
+ *(.relefi_runtime_data)
+ }
+
+ .efi_runtime_rel_stop :
+ {
+ *(.__efi_runtime_rel_stop)
+ }
+
+ . = ALIGN(4);
+
.image_copy_end :
{
*(.__image_copy_end)
diff --git a/arch/arm/lib/sections.c b/arch/arm/lib/sections.c
index a1205c3..6a94522 100644
--- a/arch/arm/lib/sections.c
+++ b/arch/arm/lib/sections.c
@@ -27,4 +27,8 @@
char __rel_dyn_end[0] __attribute__((section(".__rel_dyn_end")));
char __secure_start[0] __attribute__((section(".__secure_start")));
char __secure_end[0] __attribute__((section(".__secure_end")));
+char __efi_runtime_start[0] __attribute__((section(".__efi_runtime_start")));
+char __efi_runtime_stop[0] __attribute__((section(".__efi_runtime_stop")));
+char __efi_runtime_rel_start[0] __attribute__((section(".__efi_runtime_rel_start")));
+char __efi_runtime_rel_stop[0] __attribute__((section(".__efi_runtime_rel_stop")));
char _end[0] __attribute__((section(".__end")));