feat(imx8mp): add BL31 PIE support

Enable PIE support so the BL31 firmware can be loaded from anywhere
within the OCRAM (SRAM). How important this is shows the back and forth
of the BL31_BASE address starting with TF-A v2.5. Since then the
BL31_BASE address wasn't stable and choosing the correct combination of
SPL version loadaddress and TF-A version loadaddr was tricky.

For the PIE support we only need to replace the BL31_BASE by the
BL31_START which is a relocatable symbol and to enable it by setting
ENABLE_PIE := 1.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Change-Id: I4214db1f27120f9f9cd1413ccd7a5a7d095ff45d

diff --git a/plat/imx/imx8m/imx8mp/imx8mp_bl31_setup.c b/plat/imx/imx8m/imx8mp/imx8mp_bl31_setup.c
index 4221633e0543f9f18c626721f5a1662221c694b0..a5edf9880a3a4f48019c74a401134174a993cb97 100644 (file)
--- a/plat/imx/imx8m/imx8mp/imx8mp_bl31_setup.c
+++ b/plat/imx/imx8m/imx8mp/imx8mp_bl31_setup.c
@@ -176,7 +176,7 @@ void bl31_early_platform_setup2(u_register_t arg0, u_register_t arg1,
 }
 
 #define MAP_BL31_TOTAL                                                                            \
-       MAP_REGION_FLAT(BL31_BASE, BL31_SIZE, MT_MEMORY | MT_RW | MT_SECURE)
+       MAP_REGION_FLAT(BL31_START, BL31_SIZE, MT_MEMORY | MT_RW | MT_SECURE)
 #define MAP_BL31_RO                                                                               \
        MAP_REGION_FLAT(BL_CODE_BASE, BL_CODE_END - BL_CODE_BASE, MT_MEMORY | MT_RO | MT_SECURE)
 #define MAP_COHERENT_MEM                                                                          \

diff --git a/plat/imx/imx8m/imx8mp/platform.mk b/plat/imx/imx8m/imx8mp/platform.mk
index e8669e5f844754468855a1c69605413e0f342856..b8fdbab1c56f84631958e5202763f6a8ea05cfe9 100644 (file)
--- a/plat/imx/imx8m/imx8mp/platform.mk
+++ b/plat/imx/imx8m/imx8mp/platform.mk
@@ -138,6 +138,7 @@ $(ROTPK_HASH): $(ROT_KEY)
        ${OPENSSL_BIN_PATH}/openssl dgst -sha256 -binary > $@ 2>/dev/null
 endif
 
+ENABLE_PIE             :=      1
 USE_COHERENT_MEM       :=      1
 RESET_TO_BL31          :=      1
 A53_DISABLE_NON_TEMPORAL_HINT := 0