feat(imx8mn): optionally take params from BL2

Optionally take params from BL2 to offer more flexibility to BL2 on
where and if a BL32 image is expected. This uses imx_bl31_params_parse()
to check if arg0 can safely be accessed as a pointer and actually
contains a bl_params_t structure. If not, the hardcoded parameter
values are used as before.

Change-Id: Ia12d35778f4d550860e517f2a1f5c5d062f3283a
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
diff --git a/plat/imx/imx8m/imx8mn/imx8mn_bl31_setup.c b/plat/imx/imx8m/imx8mn/imx8mn_bl31_setup.c
index f9e430b..befa769 100644
--- a/plat/imx/imx8m/imx8mn/imx8mn_bl31_setup.c
+++ b/plat/imx/imx8m/imx8mn/imx8mn_bl31_setup.c
@@ -29,6 +29,7 @@
 #include <imx8m_csu.h>
 #include <imx8m_snvs.h>
 #include <platform_def.h>
+#include <plat_common.h>
 #include <plat_imx8.h>
 
 #define TRUSTY_PARAMS_LEN_BYTES      (4096*2)
@@ -126,7 +127,7 @@
 	unsigned int console_base = IMX_BOOT_UART_BASE;
 	static console_t console;
 	unsigned int val;
-	int i;
+	int i, ret;
 
 	/* Enable CSU NS access permission */
 	for (i = 0; i < 64; i++) {
@@ -192,6 +193,13 @@
 #endif
 #endif
 
+	ret = imx_bl31_params_parse(arg0, IMX_NS_OCRAM_SIZE, IMX_NS_OCRAM_BASE,
+				    &bl32_image_ep_info, &bl33_image_ep_info);
+	if (ret != 0) {
+		imx_bl31_params_parse(arg0, IMX_TCM_BASE, IMX_TCM_SIZE,
+				      &bl32_image_ep_info, &bl33_image_ep_info);
+	}
+
 #if !defined(SPD_opteed) && !defined(SPD_trusty)
 	enable_snvs_privileged_access();
 #endif