plat/arm: Fix BL31_BASE when RESET_TO_BL31=1

The value of BL31_BASE currently depends on the size of BL31. This
causes problems in the RESET_TO_BL31 case because the value of
BL31_BASE is used in the model launch parameters, which often changes.

Therefore, this patch fixes BL31_BASE to the middle of Trusted SRAM,
to avoid further model parameter changes in future.

Change-Id: I6d7fa4fe293717d84768974679539c0e0cb6d935
Signed-off-by: David Cunado <david.cunado@arm.com>

docs/user-guide.rst

@@ -1593,15 +1593,15 @@ with 8 CPUs using the AArch64 build of ARM Trusted Firmware.
     -C cluster0.NUM_CORES=4                                      \
     -C cluster1.NUM_CORES=4                                      \
     -C cache_state_modelled=1                                    \
-    -C cluster0.cpu0.RVBAR=0x04023000                            \
-    -C cluster0.cpu1.RVBAR=0x04023000                            \
-    -C cluster0.cpu2.RVBAR=0x04023000                            \
-    -C cluster0.cpu3.RVBAR=0x04023000                            \
-    -C cluster1.cpu0.RVBAR=0x04023000                            \
-    -C cluster1.cpu1.RVBAR=0x04023000                            \
-    -C cluster1.cpu2.RVBAR=0x04023000                            \
-    -C cluster1.cpu3.RVBAR=0x04023000                            \
-    --data cluster0.cpu0="<path-to>/<bl31-binary>"@0x04023000    \
+    -C cluster0.cpu0.RVBAR=0x04020000                            \
+    -C cluster0.cpu1.RVBAR=0x04020000                            \
+    -C cluster0.cpu2.RVBAR=0x04020000                            \
+    -C cluster0.cpu3.RVBAR=0x04020000                            \
+    -C cluster1.cpu0.RVBAR=0x04020000                            \
+    -C cluster1.cpu1.RVBAR=0x04020000                            \
+    -C cluster1.cpu2.RVBAR=0x04020000                            \
+    -C cluster1.cpu3.RVBAR=0x04020000                            \
+    --data cluster0.cpu0="<path-to>/<bl31-binary>"@0x04020000    \
     --data cluster0.cpu0="<path-to>/<bl32-binary>"@0x04001000    \
     --data cluster0.cpu0="<path-to>/<bl33-binary>"@0x88000000    \
     --data cluster0.cpu0="<path-to>/<fdt>"@0x82000000            \
@@ -1678,15 +1678,15 @@ boot Linux with 8 CPUs using the AArch64 build of ARM Trusted Firmware.
     -C bp.secure_memory=1                                        \
     -C bp.tzc_400.diagnostics=1                                  \
     -C cache_state_modelled=1                                    \
-    -C cluster0.cpu0.RVBARADDR=0x04023000                        \
-    -C cluster0.cpu1.RVBARADDR=0x04023000                        \
-    -C cluster0.cpu2.RVBARADDR=0x04023000                        \
-    -C cluster0.cpu3.RVBARADDR=0x04023000                        \
-    -C cluster1.cpu0.RVBARADDR=0x04023000                        \
-    -C cluster1.cpu1.RVBARADDR=0x04023000                        \
-    -C cluster1.cpu2.RVBARADDR=0x04023000                        \
-    -C cluster1.cpu3.RVBARADDR=0x04023000                        \
-    --data cluster0.cpu0="<path-to>/<bl31-binary>"@0x04023000    \
+    -C cluster0.cpu0.RVBARADDR=0x04020000                        \
+    -C cluster0.cpu1.RVBARADDR=0x04020000                        \
+    -C cluster0.cpu2.RVBARADDR=0x04020000                        \
+    -C cluster0.cpu3.RVBARADDR=0x04020000                        \
+    -C cluster1.cpu0.RVBARADDR=0x04020000                        \
+    -C cluster1.cpu1.RVBARADDR=0x04020000                        \
+    -C cluster1.cpu2.RVBARADDR=0x04020000                        \
+    -C cluster1.cpu3.RVBARADDR=0x04020000                        \
+    --data cluster0.cpu0="<path-to>/<bl31-binary>"@0x04020000    \
     --data cluster0.cpu0="<path-to>/<bl32-binary>"@0x04001000    \
     --data cluster0.cpu0="<path-to>/<bl33-binary>"@0x88000000    \
     --data cluster0.cpu0="<path-to>/<fdt>"@0x82000000            \

include/plat/arm/common/arm_def.h

@@ -292,6 +292,13 @@
 #define BL31_BASE			ARM_AP_TZC_DRAM1_BASE
 #define BL31_LIMIT			(ARM_AP_TZC_DRAM1_BASE +	\
 						PLAT_ARM_MAX_BL31_SIZE)
+#elif (RESET_TO_BL31)
+/*
+ * Put BL31_BASE in the middle of the Trusted SRAM.
+ */
+#define BL31_BASE			(ARM_TRUSTED_SRAM_BASE + \
+						(PLAT_ARM_TRUSTED_SRAM_SIZE >> 1))
+#define BL31_LIMIT			(ARM_BL_RAM_BASE + ARM_BL_RAM_SIZE)
 #else
 /*
  * Put BL31 at the top of the Trusted SRAM.