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>

2 files changed, 10 insertions, 29 deletions

diff --git a/plat/mediatek/mt6795/bl31_plat_setup.c b/plat/mediatek/mt6795/bl31_plat_setup.c
index 803f1ed8..32f01572 100644
--- a/plat/mediatek/mt6795/bl31_plat_setup.c
+++ b/plat/mediatek/mt6795/bl31_plat_setup.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016-2017, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2016-2018, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -21,22 +21,21 @@
 #include <plat_private.h>
 #include <platform.h>
 #include <string.h>
+#include <utils_def.h>
 #include <xlat_tables.h>
+
 /*******************************************************************************
  * Declarations of linker defined symbols which will help us find the layout
  * of trusted SRAM
  ******************************************************************************/
-unsigned long __RO_START__;
-unsigned long __RO_END__;
-
 /*
  * The next 2 constants identify the extents of the code & RO data 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
  * __RO_START__ and __RO_END__ linker symbols refer to page-aligned addresses.
  */
-#define BL31_RO_BASE (unsigned long)(&__RO_START__)
-#define BL31_RO_LIMIT (unsigned long)(&__RO_END__)
+IMPORT_SYM(unsigned long, __RO_START__,	BL31_RO_BASE);
+IMPORT_SYM(unsigned long, __RO_END__,	BL31_RO_LIMIT);
 
 /*
  * Placeholder variables for copying the arguments that have been passed to
diff --git a/plat/mediatek/mt8173/bl31_plat_setup.c b/plat/mediatek/mt8173/bl31_plat_setup.c
index 7b293077..e51bdbb9 100644
--- a/plat/mediatek/mt8173/bl31_plat_setup.c
+++ b/plat/mediatek/mt8173/bl31_plat_setup.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -17,24 +17,6 @@
 #include <platform.h>
 #include <spm.h>
 
-/*******************************************************************************
- * Declarations of linker defined symbols which will help us find the layout
- * of trusted SRAM
- ******************************************************************************/
-unsigned long __RO_START__;
-unsigned long __RO_END__;
-
-/*
- * The next 3 constants identify the extents of the code, RO data region and the
- * limit of the BL31 image.  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 __RO_START__, __RO_END__ & __BL31_END__ linker symbols
- * refer to page-aligned addresses.
- */
-#define BL31_RO_BASE (unsigned long)(&__RO_START__)
-#define BL31_RO_LIMIT (unsigned long)(&__RO_END__)
-#define BL31_END (unsigned long)(&__BL31_END__)
-
 static entry_point_info_t bl32_ep_info;
 static entry_point_info_t bl33_ep_info;
 
@@ -156,10 +138,10 @@ void bl31_plat_arch_setup(void)
 	plat_cci_init();
 	plat_cci_enable();
 
-	plat_configure_mmu_el3(BL31_RO_BASE,
-			       BL_COHERENT_RAM_END - BL31_RO_BASE,
-			       BL31_RO_BASE,
-			       BL31_RO_LIMIT,
+	plat_configure_mmu_el3(BL_CODE_BASE,
+			       BL_COHERENT_RAM_END - BL_CODE_BASE,
+			       BL_CODE_BASE,
+			       BL_CODE_END,
 			       BL_COHERENT_RAM_BASE,
 			       BL_COHERENT_RAM_END);
 }