imx-spl: use fdt-overlay to pass bl31_configs over bl31

Use FDT-OVERLAY as part of updatable TEE-FIT image to pass config
data to BL31 as part of Part Number so BL31's behaviour could be
overriden.

2 files changed, 127 insertions, 17 deletions

diff --git a/arch/arm/mach-imx/spl.c b/arch/arm/mach-imx/spl.c
index 0a9a34f410..2a6f3506b6 100644
--- a/arch/arm/mach-imx/spl.c
+++ b/arch/arm/mach-imx/spl.c
@@ -8,6 +8,8 @@
 
 #define DEBUG
 
+#include <linux/libfdt.h>
+
 #include <common.h>
 #include <hang.h>
 #include <init.h>
@@ -286,6 +288,42 @@ static inline void raw_write_daif(unsigned int daif)
 }
 
 static bool is_tee_present = false;
+/* static uintptr_t configs_addr;
+ * TODO: define bl31_configs data structure passing into BL31 from SPL
+ */
+static struct bl31_configs {
+	bool       tee_presence;
+	const char *config_1;
+	uint32_t   config_2;
+} g_configs;
+static void *g_fdtoverlay;
+#define ATF_CONFIGS_NODE "/atf-configs"
+#define PROP_STRING_1    "property-2"
+#define PROP_UINT32_1    "property-1"
+
+static int open_and_fetch_bl31_configs(uintptr_t configs_addr/*OUT*/, void *fdt_addr/*IN*/)
+{
+        int ret = fdt_check_header((void *)fdt_addr);
+        if (!ret) {
+                g_fdtoverlay = (void *)fdt_addr;
+        }
+
+        if (!ret) {
+                int node = fdt_path_offset(g_fdtoverlay, ATF_CONFIGS_NODE);
+                if (node < 0) {
+			printf("Fail finding atf_config DT node\n");
+                }
+
+                const fdt32_t *cuint;
+                const char *prop = fdt_getprop(g_fdtoverlay, node, PROP_STRING_1, NULL);
+                cuint = fdt_getprop(g_fdtoverlay, node, PROP_UINT32_1, NULL);
+                printf("property-1 = %s, property-2 = %d\n", prop, fdt32_to_cpu(*cuint));
+                // uint32_t size = fdt_read_uint32_default(fdt, node, "st,mem-size", 0U);
+        }
+
+        return ret;
+}
+
 __weak void __noreturn jump_to_image_no_args(struct spl_image_info *spl_image)
 {
 	typedef void __noreturn (*image_entry_noargs_t)(void);
@@ -297,13 +335,21 @@ __weak void __noreturn jump_to_image_no_args(struct spl_image_info *spl_image)
 
 	debug("image entry point: 0x%p\n", (void *)spl_image->entry_point);
 	if (spl_image->flags & SPL_FIT_FOUND) {
-		debug("BL31 image entry point: 0x%p. \n", (void *)spl_image->entry_point);
+		debug("BL31 image entry point: 0x%p fdt_addr = 0x%p. \n",
+			       	(void *)spl_image->entry_point, (void *)spl_image->fdt_addr);
 
 		typedef void __noreturn (*bl31_entry)(int, int, int, int);
 		bl31_entry bl31_entry_point = (bl31_entry)(unsigned long)spl_image->entry_point;
 	        raw_write_daif(SPSR_EXCEPTION_MASK);
         	dcache_disable();
-		bl31_entry_point(is_tee_present, 22, 32, 44);
+
+		/*
+		 * Note: Avoid adding libfdt.a to imx-atf-bl31 to overflow OCRAM
+		 * instead private bl31_configs data structure is passed over bl31.
+		 */
+		open_and_fetch_bl31_configs(&g_configs, spl_image->fdt_addr);
+		g_configs.tee_presence = is_tee_present;
+		bl31_entry_point(0, &g_configs, 32, 44);
 	} else {
 		/*
 		 * HAB looks for the CSF at the end of the authenticated
@@ -489,11 +535,36 @@ int mmc_image_load_late(struct spl_image_info *spl_image, struct mmc *mmc)
 #endif
 
 #ifdef CONFIG_IMX_AERQ_PARTNUM_BOOT_SCHEME
-/* Forward declaration of h_spl_load_read(), see detail implementation in
+static int spl_fit_append_fdtoverlay(void *fdt_addr, struct spl_image_info *tee_info)
+{
+	int ret = 0;
+	
+	/* Make room in FDT for changes from the overlay */
+	if (!tee_info || !tee_info->fdt_addr)
+		return -1;
+
+	ret = fdt_increase_size(fdt_addr, tee_info->size);
+	if (ret < 0)
+		return ret;
+
+	ret = fdt_overlay_apply_verbose(fdt_addr,
+					(void *)tee_info->fdt_addr);
+	if (ret) {
+		pr_err("failed to apply DT overlay!\n");
+	} else {
+		debug("%s: TEE-FIT DT overlay applied spl_image->fdt_addr = 0x%p tee_info->fdt_addr = 0x%p \n",
+			       	__func__, fdt_addr, (void *)tee_info->fdt_addr);
+	}
+
+	return ret;
+}
+
+/*
+ * Forward declaration of h_spl_load_read(), see detail implementation in
  * common/spl/spl_mmc.c.
  */
 ulong h_spl_load_read(struct spl_load_info *load, ulong sector,
-                      ulong count, void *buf);
+	          	ulong count, void *buf);
 int mmc_image_load_late(struct spl_image_info *spl_image, struct mmc *mmc)
 {
 	unsigned long count = 0, sector = CONFIG_MMCSD_RAW_MODE_TEE_FIT_SECTOR; // 2M bytes offset by default
@@ -502,12 +573,15 @@ int mmc_image_load_late(struct spl_image_info *spl_image, struct mmc *mmc)
 	struct spl_image_info tee_fit_info;
 	int ret = 0;
 
+	/*
+	 * Note: input *spl_image carries global FIT images information
+	 * (u-boot/dtb and tee/dtb-overlay FIT images ) and will be passing around
+	 */
 	memset(&tee_fit_info, 0, sizeof(tee_fit_info));
 	/* Avoid overwriting previously loaded u-boot at 0x40200000 */
 	header = spl_get_load_buffer(-sizeof(*header) - bd->blksz, 0);
 
 	/* read FIT image header to find the image size & load address */
-	/* TODO: BL32-FIT eMMC sector offset will be fetched from u-boot-fit-fdt as predefined */
 	count = blk_dread(bd, sector, 1, header);
 	debug("bl31 hdr read sector %lx, count=%lu\n", sector, count);
 	if (count == 0) {
@@ -528,6 +602,8 @@ int mmc_image_load_late(struct spl_image_info *spl_image, struct mmc *mmc)
 		if (!ret) {
 			/* So far bl32-fit image is detected/loaded and authN'ed. */
 			is_tee_present = true;
+
+			ret = spl_fit_append_fdtoverlay(spl_image->fdt_addr, &tee_fit_info);
 			/* TODO: cache local tee_fit_info into global spl_image object for
 			 * passing config data into other stage of bootloader.
 			 * spl_image( need to be extended ) to cache BL32 specifc info from BL32-FDT
@@ -538,10 +614,6 @@ int mmc_image_load_late(struct spl_image_info *spl_image, struct mmc *mmc)
 		debug("Found BL32-FIT and loading result = %d.\n", ret);
 	}	
 
-	// 1. Load optee tee.bin to TEE_LOAD_ADDR
-	// if not detected, is_tee_present = false;
-	// 2. HAB4 authenticate the image
-	// 3. Cache optee entry_point into spl_image->fdt_addr
 	return ret;
 }
 #endif
diff --git a/common/spl/spl_fit.c b/common/spl/spl_fit.c
index 77516d8d7d..3677dda0f0 100644
--- a/common/spl/spl_fit.c
+++ b/common/spl/spl_fit.c
@@ -394,8 +394,8 @@ static bool os_takes_devicetree(uint8_t os)
 	case IH_OS_U_BOOT:
 		return true;
 	case IH_OS_TEE:
-		/* TODO: Change to true to allow op-tee-fit image to carry fdt-overlay to override default behaviour. */
-		return false;
+		/* allow op-tee-fit image to carry fdt-overlay to override default behaviour. */
+		return true;
 	case IH_OS_LINUX:
 		return IS_ENABLED(CONFIG_SPL_OS_BOOT);
 	default:
@@ -437,7 +437,7 @@ static int spl_fit_append_fdt(struct spl_image_info *spl_image,
 			return ret;
 	}
 
-	/* Make the load-address of the FDT available for the SPL framework */
+	/* Make the load-address of the FDT available  */
 	spl_image->fdt_addr = map_sysmem(image_info.load_addr, 0);
 	debug("%s FDT node addr = 0x%p. load_addr = %p\n", __func__, (void *)spl_image->fdt_addr, (void *)image_info.load_addr);
 	if (CONFIG_IS_ENABLED(FIT_IMAGE_TINY))
@@ -719,13 +719,48 @@ static int spl_simple_fit_parse(struct spl_fit_info *ctx)
 	ctx->images_node = fdt_path_offset(ctx->fit, FIT_IMAGES_PATH);
 	if (ctx->images_node < 0) {
 		debug("%s: Cannot find /images node: %d\n", __func__,
-		      ctx->images_node);
+			ctx->images_node);
 		return -EINVAL;
 	}
 
 	return 0;
 }
 
+static int spl_fit_fetch_fdt(struct spl_image_info *spl_image, /*IN/OUT*/
+			      struct spl_load_info *info, ulong sector,
+			      const struct spl_fit_info *ctx)
+{
+	struct spl_image_info image_info;
+	int node, ret = 0;
+
+	/*
+	 * Use the address following the image as target address for the
+	 * device tree.
+	 */
+	image_info.load_addr = spl_image->load_addr + spl_image->size;
+
+	/* Figure out which device tree the board wants to use */
+	node = spl_fit_get_image_node(ctx, FIT_FDT_PROP, 0);
+	if (node < 0) {
+		debug("%s: cannot find FDT node\n", __func__);
+		return node;
+	} else {
+		ret = spl_load_fit_image(info, sector, ctx, node,
+					 &image_info);
+		if (ret < 0)
+			return ret;
+	}
+
+	/* Pass out tee_fdtoverlay image information to the caller */
+	spl_image->fdt_addr  = map_sysmem(image_info.load_addr, 0);
+	spl_image->load_addr = image_info.load_addr;
+	spl_image->size      = image_info.size;
+
+	debug("%s FDT node addr = 0x%p. load_addr = %p, fetched from TEE-FIT\n", __func__,
+			(void *)spl_image->fdt_addr, (void *)image_info.load_addr);
+	return ret;
+}
+
 int spl_load_simple_fit(struct spl_image_info *spl_image,
 			struct spl_load_info *info, ulong sector, void *fit)
 {
@@ -736,7 +771,7 @@ int spl_load_simple_fit(struct spl_image_info *spl_image,
 	int index = 0;
 	int firmware_node;
 
-	/* Read out entire FDT */
+	/* Read out entire FDT from current FIT image. */
 	ret = spl_simple_fit_read(&ctx, info, sector, fit);
 	if (ret < 0)
 		return ret;
@@ -788,7 +823,7 @@ int spl_load_simple_fit(struct spl_image_info *spl_image,
 	}
 	if (node < 0) {
 		debug("%s: Cannot find u-boot image node: %d\n",
-		      __func__, node);
+			__func__, node);
 		return -1;
 	}
 
@@ -811,14 +846,17 @@ int spl_load_simple_fit(struct spl_image_info *spl_image,
 	 */
 	if (os_takes_devicetree(spl_image->os)) {
 		if (IH_OS_TEE == spl_image->os) {
-		/* TODO: fetch fdt_overlay tee.dbo and apply to global spl_image->fdt_addr (U-Boot.dtb) */
-
+		/* Fetch fdt_overlay tee.dbo and later apply to global (U-Boot.dtb) */
+			ret = spl_fit_fetch_fdt(spl_image, info, sector, &ctx);
+			if (ret)
+				return ret;
 		} else {
 			ret = spl_fit_append_fdt(spl_image, info, sector, &ctx);
 			if (ret < 0 && spl_image->os != IH_OS_U_BOOT)
 				return ret;
 		}
 	}
+
 	firmware_node = node;
 	/* Now check if there are more images for us to load */
 	for (; ; index++) {