ODROID-COMMON: fix to load device tree files matches to kernel version

Boot directory in Linux system may contains multiple kernel versions
with dedicated device tree files, but boot loader does not know about
kernel version to start if not given by 'fk_kvers'. So this patch is to
gather 'fk_kvers' from 'config.ini' if set via 'fk_kvers=...' or if
there is a symbolic link file 'dtb' that points to the device tree file
under 'dtbs/<kernel version/rockchip/<device tree file>.

Signed-off-by: Dongjin Kim <tobetter@gmail.com>
Change-Id: I576f6f40690a3552c334289b078a9efceea757c8

Author: tobetter

board/hardkernel/odroid-common/board.c

@@ -212,10 +212,10 @@ int rk_board_late_init(void)
 	return 0;
 }
 
-int dtoverlay_apply(void *fdt, const char *dtoverlay, struct blk_desc *dev_desc)
+int dtoverlay_apply(void *fdt, const char *dtoverlay, struct blk_desc *dev_desc,
+		const char *root)
 {
 	char *paths[] = {
-		"",
 		"overlays/"CONFIG_BOARDNAME"/",
 		"rockchip/overlays/"CONFIG_BOARDNAME"/",
 	};
@@ -229,7 +229,7 @@ int dtoverlay_apply(void *fdt, const char *dtoverlay, struct blk_desc *dev_desc)
 	ulong fdt_dtbo = env_get_ulong("loadaddr", 16, 0);
 
 	for (i = 0; i < ARRAY_SIZE(paths); i++) {
-		snprintf(buf, sizeof(buf), "%s%s.dtbo", paths[i], dtoverlay);
+		snprintf(buf, sizeof(buf), "%s%s%s.dtbo", root, paths[i], dtoverlay);
 
 		if (dev_desc)
 			ret = load_from_mmc(fdt_dtbo, dev_desc->devnum, 1, buf);
@@ -247,49 +247,78 @@ int dtoverlay_apply(void *fdt, const char *dtoverlay, struct blk_desc *dev_desc)
 	return -1;
 }
 
+static int load_boot_config(void)
+{
+	int ret = -EINVAL;
+
+	run_command_list(
+			"load mmc 0:1 $loadaddr config.ini;"
+			"ini generic $loadaddr",
+			-1, 0);
+
+	char *overlay_profile = env_get("overlay_profile");
+	if (overlay_profile) {
+		char buf[32];
+		snprintf(buf, sizeof(buf), "ini overlay_%s $loadaddr", overlay_profile);
+		run_command(buf, 0);
+	}
+
+	char *overlays = env_get("overlays");
+	const char *token = strtok(overlays, " ");
+	while (token != NULL) {
+		if (!strncmp(token, "display_", 8)) {
+			ret = set_panel_name(token);
+			break;
+		}
+		token = strtok(NULL, " ");
+	}
+
+	return ret;
+}
+
 int board_read_dtb_file(void *fdt_addr)
 {
 	int ret;
 
 	ret = load_from_cramfs((unsigned long)fdt_addr, CONFIG_ROCKCHIP_EARLY_DISTRO_DTB_PATH);
 	if (!ret) {
 		if (panel)
-			ret = dtoverlay_apply(fdt_addr, panel, NULL);
+			ret = dtoverlay_apply(fdt_addr, panel, NULL, NULL);
 	} else {
+		load_boot_config();
+
 		char *paths[] = {
 			"dtb",
 			"rockchip/"CONFIG_ROCKCHIP_EARLY_DISTRO_DTB_PATH,
 		};
 		struct blk_desc *dev_desc = rockchip_get_bootdev();
 		int i;
+		char buf[1024];
+		char root[1024];
+
+		char *kvers = env_get("fk_kvers");
+		if (!kvers) {
+			/* Try to get kernel version from 'dtb' which must
+			 * be symbol link of device tree file in Linux
+			 */
+			load_from_mmc((unsigned long)fdt_addr, dev_desc->devnum, 1, "dtb");
+		}
+
+		kvers = env_get("fk_kvers");
+		if (kvers) {
+			/* Set default device tree file with given kernel version */
+			snprintf(root, sizeof(root), "dtbs/%s/rockchip/", kvers);
+			strcpy(buf, root);
+			strcat(buf, CONFIG_ROCKCHIP_EARLY_DISTRO_DTB_PATH);
+
+			paths[0] = buf;
+		}
 
 		for (i = 0; i < ARRAY_SIZE(paths); i++) {
 			ret = load_from_mmc((unsigned long)fdt_addr, dev_desc->devnum, 1, paths[i]);
 			if (!ret) {
-				run_command_list(
-						"load mmc 0:1 $loadaddr config.ini;"
-						"ini generic $loadaddr",
-						-1, 0);
-
-				char *overlay_profile = env_get("overlay_profile");
-				if (overlay_profile) {
-					char buf[32];
-					snprintf(buf, sizeof(buf), "ini overlay_%s $loadaddr", overlay_profile);
-					run_command(buf, 0);
-				}
-
-				char *overlays = env_get("overlays");
-				const char *token = strtok(overlays, " ");
-				while (token != NULL) {
-					if (!strncmp(token, "display_", 8)) {
-						set_panel_name(token);
-						break;
-					}
-					token = strtok(NULL, " ");
-				}
-
 				if (panel)
-					ret = dtoverlay_apply(fdt_addr, panel, dev_desc);
+					ret = dtoverlay_apply(fdt_addr, panel, dev_desc, root);
 				break;
 			}
 		}

fs/ext4/ext4_common.c

@@ -2241,7 +2241,6 @@ static int ext4fs_find_file1(const char *currpath,
 			}
 
 			debug("Got symlink >%s<\n", symlink);
-
 			if (symlink[0] == '/') {
 				ext4fs_free_node(oldnode, currroot);
 				oldnode = &ext4fs_root->diropen;
@@ -2251,6 +2250,14 @@ static int ext4fs_find_file1(const char *currpath,
 			status = ext4fs_find_file1(symlink, oldnode,
 						    &currnode, &type);
 
+			/* Take kernel version from symlink path if start
+			 * with 'dtbs/.../...' and store it to 'fk_kvers'
+			 */
+			if (!strncmp(symlink, "dtbs/", 5)) {
+				char *token = strtok(symlink + 5, "/");
+				env_set("fk_kvers", token);
+			}
+
 			free(symlink);
 
 			if (status == 0) {