1 files changed, 42 insertions, 0 deletions
diff --git a/arch/um/kernel/dtb.c b/arch/um/kernel/dtb.c
new file mode 100644
index 000000000000..47cd3d869fb2
--- /dev/null
+++ b/arch/um/kernel/dtb.c
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/init.h>
+#include <linux/of_fdt.h>
+#include <linux/printk.h>
+#include <linux/memblock.h>
+#include <init.h>
+
+#include "um_arch.h"
+
+static char *dtb __initdata;
+
+void uml_dtb_init(void)
+{
+	long long size;
+	void *area;
+
+	area = uml_load_file(dtb, &size);
+	if (area) {
+		if (!early_init_dt_scan(area, __pa(area))) {
+			pr_err("invalid DTB %s\n", dtb);
+			memblock_free(area, size);
+			return;
+		}
+
+		early_init_fdt_scan_reserved_mem();
+	}
+
+	unflatten_device_tree();
+}
+
+static int __init uml_dtb_setup(char *line, int *add)
+{
+	*add = 0;
+	dtb = line;
+	return 0;
+}
+
+__uml_setup("dtb=", uml_dtb_setup,
+"dtb=<file>\n"
+"    Boot the kernel with the devicetree blob from the specified file.\n\n"
+);