Clean usage of void pointers to access symbols
Void pointers have been used to access linker symbols, by declaring an
extern pointer, then taking the address of it. This limits symbols
values to aligned pointer values. To remove this restriction an
IMPORT_SYM macro has been introduced, which declares it as a char
pointer and casts it to the required type.
Change-Id: I89877fc3b13ed311817bb8ba79d4872b89bfd3b0
Signed-off-by: Joel Hutton <Joel.Hutton@Arm.com>
diff --git a/include/common/bl_common.h b/include/common/bl_common.h
index 4ef916f..09a394d 100644
--- a/include/common/bl_common.h
+++ b/include/common/bl_common.h
@@ -64,33 +64,41 @@
#include <types.h>
#include <utils_def.h> /* To retain compatibility */
+
/*
* Declarations of linker defined symbols to help determine memory layout of
* BL images
*/
#if SEPARATE_CODE_AND_RODATA
-extern uintptr_t __TEXT_START__;
-extern uintptr_t __TEXT_END__;
-extern uintptr_t __RODATA_START__;
-extern uintptr_t __RODATA_END__;
+IMPORT_SYM(unsigned long, __TEXT_START__, BL_CODE_BASE);
+IMPORT_SYM(unsigned long, __TEXT_END__, BL_CODE_END);
+IMPORT_SYM(unsigned long, __RODATA_START__, BL_RO_DATA_BASE);
+IMPORT_SYM(unsigned long, __RODATA_END__, BL_RO_DATA_END);
#else
-extern uintptr_t __RO_START__;
-extern uintptr_t __RO_END__;
+IMPORT_SYM(unsigned long, __RO_START__, BL_CODE_BASE);
+IMPORT_SYM(unsigned long, __RO_END__, BL_CODE_END);
#endif
#if defined(IMAGE_BL2)
-extern uintptr_t __BL2_END__;
+IMPORT_SYM(unsigned long, __BL2_END__, BL2_END);
#elif defined(IMAGE_BL2U)
-extern uintptr_t __BL2U_END__;
+IMPORT_SYM(unsigned long, __BL2U_END__, BL2U_END);
#elif defined(IMAGE_BL31)
-extern uintptr_t __BL31_END__;
+IMPORT_SYM(unsigned long, __BL31_END__, BL31_END);
#elif defined(IMAGE_BL32)
-extern uintptr_t __BL32_END__;
+IMPORT_SYM(unsigned long, __BL32_END__, BL32_END);
#endif /* IMAGE_BLX */
+/*
+ * The next 2 constants identify the extents of the coherent memory region.
+ * These addresses are used by the MMU setup code and therefore they must be
+ * page-aligned. It is the responsibility of the linker script to ensure that
+ * __COHERENT_RAM_START__ and __COHERENT_RAM_END__ linker symbols refer to
+ * page-aligned addresses.
+ */
#if USE_COHERENT_MEM
-extern uintptr_t __COHERENT_RAM_START__;
-extern uintptr_t __COHERENT_RAM_END__;
+IMPORT_SYM(unsigned long, __COHERENT_RAM_START__, BL_COHERENT_RAM_BASE);
+IMPORT_SYM(unsigned long, __COHERENT_RAM_END__, BL_COHERENT_RAM_END);
#endif
/*******************************************************************************
diff --git a/include/common/runtime_svc.h b/include/common/runtime_svc.h
index d12af22..5d9fa39 100644
--- a/include/common/runtime_svc.h
+++ b/include/common/runtime_svc.h
@@ -122,8 +122,8 @@
void runtime_svc_init(void);
uintptr_t handle_runtime_svc(uint32_t smc_fid, void *cookie, void *handle,
unsigned int flags);
-extern uintptr_t __RT_SVC_DESCS_START__;
-extern uintptr_t __RT_SVC_DESCS_END__;
+IMPORT_SYM(uintptr_t, __RT_SVC_DESCS_START__, RT_SVC_DESCS_START);
+IMPORT_SYM(uintptr_t, __RT_SVC_DESCS_END__, RT_SVC_DESCS_END);
void init_crash_reporting(void);
extern uint8_t rt_svc_descs_indices[MAX_RT_SVCS];