dt: add helper for empty dt creation

[qemu.git] / device_tree.c

diff --git a/device_tree.c b/device_tree.c
index 2f127b71b0d4d5654f93b0e83cf65bae493e3406..d0378961f0f216a875ce76e872dde51de4ab0b95 100644 (file)
--- a/device_tree.c
+++ b/device_tree.c
@@ -25,6 +25,43 @@
 
 #include <libfdt.h>
 
+#define FDT_MAX_SIZE  0x10000
+
+void *create_device_tree(int *sizep)
+{
+    void *fdt;
+    int ret;
+
+    *sizep = FDT_MAX_SIZE;
+    fdt = g_malloc0(FDT_MAX_SIZE);
+    ret = fdt_create(fdt, FDT_MAX_SIZE);
+    if (ret < 0) {
+        goto fail;
+    }
+    ret = fdt_begin_node(fdt, "");
+    if (ret < 0) {
+        goto fail;
+    }
+    ret = fdt_end_node(fdt);
+    if (ret < 0) {
+        goto fail;
+    }
+    ret = fdt_finish(fdt);
+    if (ret < 0) {
+        goto fail;
+    }
+    ret = fdt_open_into(fdt, fdt, *sizep);
+    if (ret) {
+        fprintf(stderr, "Unable to copy device tree in memory\n");
+        exit(1);
+    }
+
+    return fdt;
+fail:
+    fprintf(stderr, "%s Couldn't create dt: %s\n", __func__, fdt_strerror(ret));
+    exit(1);
+}
+
 void *load_device_tree(const char *filename_path, int *sizep)
 {
     int dt_size;