allwinner: Add BL32 (corresponds to Trusted OS) support

This patch is an attempt to run Trusted OS (OP-TEE OS being one of them) along
side BL31 image.

ATF supports multiple SPD's that can take dispatcher name (opteed for OP-TEE OS)
as an input using the 'SPD=<dispatcher name>' option during bl31 build.
Signed-off-by: Amit Singh Tomar <amittomer25@gmail.com>

docs/plat/allwinner.rst

@@ -27,3 +27,13 @@ To build:
     make CROSS_COMPILE=aarch64-linux-gnu- PLAT=sun50i_a64 DEBUG=1 bl31
 
 .. _U-Boot documentation: http://git.denx.de/?p=u-boot.git;f=board/sunxi/README.sunxi64;hb=HEAD
+
+Trusted OS dispatcher
+=====================
+
+One can boot Trusted OS(OP-TEE OS, bl32 image) along side bl31 image on Allwinner A64.
+
+In order to include the 'opteed' dispatcher in the image, pass 'SPD=opteed' on the command line
+while compiling the bl31 image and make sure the loader (SPL) loads the Trusted OS binary to
+the beginning of DRAM (0x40000000).
+

plat/allwinner/common/include/platform_def.h

@@ -42,4 +42,10 @@
 #define PLATFORM_MMAP_REGIONS		4
 #define PLATFORM_STACK_SIZE		(0x1000 / PLATFORM_CORE_COUNT)
 
+#ifndef SPD_none
+#ifndef BL32_BASE
+#define BL32_BASE			SUNXI_DRAM_BASE
+#endif
+#endif
+
 #endif /* __PLATFORM_DEF_H__ */

plat/allwinner/common/sunxi_bl31_setup.c

@@ -18,6 +18,7 @@
 
 #include "sunxi_private.h"
 
+static entry_point_info_t bl32_image_ep_info;
 static entry_point_info_t bl33_image_ep_info;
 
 static console_16550_t console;
@@ -34,6 +35,13 @@ void bl31_early_platform_setup2(u_register_t arg0, u_register_t arg1,
 	console_16550_register(SUNXI_UART0_BASE, SUNXI_UART0_CLK_IN_HZ,
 			       SUNXI_UART0_BAUDRATE, &console);
 
+#ifdef BL32_BASE
+	/* Populate entry point information for BL32 */
+	SET_PARAM_HEAD(&bl32_image_ep_info, PARAM_EP, VERSION_1, 0);
+	SET_SECURITY_STATE(bl32_image_ep_info.h.attr, SECURE);
+	bl32_image_ep_info.pc = BL32_BASE;
+#endif
+
 	/* Populate entry point information for BL33 */
 	SET_PARAM_HEAD(&bl33_image_ep_info, PARAM_EP, VERSION_1, 0);
 	/*
@@ -72,7 +80,12 @@ void bl31_platform_setup(void)
 entry_point_info_t *bl31_plat_get_next_image_ep_info(uint32_t type)
 {
 	assert(sec_state_is_valid(type) != 0);
-	assert(type == NON_SECURE);
 
+	if (type == NON_SECURE)
 		return &bl33_image_ep_info;
+
+	if ((type == SECURE) && bl32_image_ep_info.pc)
+		return &bl32_image_ep_info;
+
+	return NULL;
 }