[D18][ENV][BOARD] add kernel mem logo fdt support

* setup kernel mem logo address
* create the necessary device tree nodes for kernel mem logo at runtime:
  the fdt_memlogo function should subsequently be exported to a common
  file to also be used with other boards.

board/seco/imx8mp_d18/imx8mp_d18.c

@@ -188,6 +188,59 @@ int dram_init_banksize(void)
 	return 0;
 }
 
+static int fdt_memlogo(void *fdt)
+{
+	uint64_t address, size;
+	char *env;
+	int node;
+	int tmp;
+
+	env = env_get("memlogo_addr");
+	if (env)
+		address = simple_strtoul(env, NULL, 16);
+	else {
+		printf("memlogo: could not get address\n");
+		return -1;
+	}
+
+	env = env_get("memlogo_size");
+	if (env) {
+		size = simple_strtoul(env, NULL, 16);
+		if (size > 0x400000) {
+			printf("memlogo: logo size too big (max: 4MiB)\n");
+			return -1;
+		}
+	} else {
+		printf("memlogo: could not get size\n");
+		return -1;
+	}
+
+	tmp = fdt_add_mem_rsv(fdt, address, size);
+	if (tmp < 0) {
+		printf("memlogo: failed to reserve memory: %s\n", fdt_strerror(tmp));
+		return tmp;
+	}
+
+	node = fdt_find_or_add_subnode(fdt, 0, "seco-memlogo");
+	if (node < 0) {
+		printf("memlogo: unable to find/create seco-memlogo node: %s\n", fdt_strerror(node));
+		return node;
+	}
+
+	tmp = fdt_setprop_string(fdt, node, "compatible", "seco,memlogo");
+	if (!tmp)
+		tmp = fdt_setprop_u32(fdt, node, "address", address);
+	if (!tmp)
+		tmp = fdt_setprop_u32(fdt, node, "size", size);
+
+	if (tmp) {
+		printf("memlogo: failed to add seco-memlogo properties: %s\n", fdt_strerror(tmp));
+		return tmp;
+	}
+
+	return 0;
+}
+
 #ifdef CONFIG_OF_BOARD_SETUP
 int ft_board_setup(void *blob, struct bd_info *bd)
 {
@@ -221,6 +274,8 @@ int ft_board_setup(void *blob, struct bd_info *bd)
 
 	strap_fdt_ram_setup(blob, bd);
 
+	fdt_memlogo(blob);
+
 	return 0;
 }
 #endif

include/configs/seco_imx8mp_d18.h

@@ -245,6 +245,9 @@
 
 #define ENV_BOOT_TYPE                      booti
 
+#define ENV_CUSTOM                               \
+	"memlogo_addr=63c00000\0"
+
 #include "seco_mx8_env.h"
 
 #endif