feat(stm32mp2): disable PIE by default on STM32MP2 platform

Allow to disable ENABLE_PIE on STM32MP2. BL31 is loaded at the beginning
of SYSRAM whatever the options set. Set ENABLE_PIE to 0 by default.
This should allow us to reduce BL31 and BL2 size.

Change-Id: Ie8c83c9205e81301eb1fdcf24b94216172586630
Signed-off-by: Maxime Méré <maxime.mere@foss.st.com>
Reviewed-on: https://gerrit.st.com/c/mpu/oe/st/tf-a/+/423949
ACI: CITOOLS <MDG-smet-aci-reviews@list.st.com>
Reviewed-by: Yann GAUTIER <yann.gautier@foss.st.com>
Domain-Review: Yann GAUTIER <yann.gautier@foss.st.com>
Reviewed-on: https://gerrit.st.com/c/mpu/oe/st/tf-a/+/438769

Author: meremST

plat/st/stm32mp2/include/platform_def.h

@@ -73,8 +73,15 @@
 /*******************************************************************************
  * BL31 specific defines.
  ******************************************************************************/
+#if ENABLE_PIE
 #define BL31_BASE			0
-#define BL31_LIMIT			(STM32MP_SEC_SYSRAM_SIZE / 2)
+#else
+#define BL31_BASE			STM32MP_SEC_SYSRAM_BASE
+#endif
+
+#define BL31_LIMIT			(BL31_BASE + (STM32MP_SEC_SYSRAM_SIZE / 2))
+
+#define BL31_PROGBITS_LIMIT		(BL31_BASE + STM32MP_BL31_SIZE)
 
 /*******************************************************************************
  * BL33 specific defines.

plat/st/stm32mp2/platform.mk

@@ -11,9 +11,11 @@ STM32_EXTRA_PARTS		:=	6
 include plat/st/common/common.mk
 
 CRASH_REPORTING			:=	1
-ENABLE_PIE			:=	1
+ENABLE_PIE			:=	0
 PROGRAMMABLE_RESET_ADDRESS	:=	1
+ifeq ($(ENABLE_PIE),1)
 BL2_IN_XIP_MEM			:=	1
+endif
 
 STM32MP_BL33_EL1		?=	1
 ifeq ($(STM32MP_BL33_EL1),1)

plat/st/stm32mp2/stm32mp2_def.h

@@ -237,8 +237,6 @@ enum ddr_type {
 #define STM32MP_BL31_SIZE		(STM32MP_SEC_SYSRAM_SIZE - \
 					 STM32MP_BL2_SIZE)
 
-#define BL31_PROGBITS_LIMIT		STM32MP_BL31_SIZE
-
 #define STM32MP_BL2_BASE		(STM32MP_SEC_SYSRAM_BASE + \
 					 STM32MP_SEC_SYSRAM_SIZE - \
 					 STM32MP_BL2_SIZE)