[U-Boot] [PATCH 28/48] x86: Allow use of global_data with EFI

[Simon Glass]

On x86 the global_data pointer is provided through a somewhat-bizarre and
x86-specific mechanism: the frame segment is set to a pointer to the start
of global_data, so that accesses can use this build-in register.

When running as an EFI payload we don't want to mess with the Global
Descriptor Table (GDT) and there is little advantage (in terms of code size)
to doing so.

Allow global_data to be a simple variable in this case.

Signed-off-by: Simon Glass <sjg at chromium.org>
---

 arch/x86/include/asm/global_data.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/x86/include/asm/global_data.h b/arch/x86/include/asm/global_data.h
index abd70b9..6df6a78 100644
--- a/arch/x86/include/asm/global_data.h
+++ b/arch/x86/include/asm/global_data.h
@@ -76,6 +76,12 @@ struct arch_global_data {
 #include <asm-generic/global_data.h>
 
 #ifndef __ASSEMBLY__
+# ifdef CONFIG_ARCH_EFI
+
+#define gd global_data_ptr
+
+#define DECLARE_GLOBAL_DATA_PTR   extern struct global_data *global_data_ptr
+# else
 static inline __attribute__((no_instrument_function)) gd_t *get_fs_gd_ptr(void)
 {
 	gd_t *gd_ptr;
@@ -88,6 +94,7 @@ static inline __attribute__((no_instrument_function)) gd_t *get_fs_gd_ptr(void)
 #define gd	get_fs_gd_ptr()
 
 #define DECLARE_GLOBAL_DATA_PTR
+# endif
 
 #endif
 
-- 
2.4.3.573.g4eafbef