Use QEMU platform code for FVP too, so we can run tests under FVP.

Change-Id: I176aeb65dbf8dbaa01185c3ee400a2a3c1b832d7
diff --git a/linux_fdt/BUILD.gn b/linux_fdt/BUILD.gn
new file mode 100644
index 0000000..ac71ad4
--- /dev/null
+++ b/linux_fdt/BUILD.gn
@@ -0,0 +1,20 @@
+# Copyright 2018 The Hafnium Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+source_set("linux_fdt") {
+  sources = [
+    "plat.c",
+    "plat_entry.S",
+  ]
+}
diff --git a/linux_fdt/plat.c b/linux_fdt/plat.c
new file mode 100644
index 0000000..8f03174
--- /dev/null
+++ b/linux_fdt/plat.c
@@ -0,0 +1,52 @@
+/*
+ * Copyright 2018 The Hafnium Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "hf/addr.h"
+#include "hf/dlog.h"
+#include "hf/fdt_handler.h"
+#include "hf/mpool.h"
+
+/* This is set by plat_entry.S. */
+uintpaddr_t plat_fdt_addr;
+
+paddr_t plat_get_fdt_addr(void)
+{
+	return pa_init(plat_fdt_addr);
+}
+
+void plat_get_initrd_range(paddr_t *begin, paddr_t *end, struct mpool *ppool)
+{
+	struct fdt_header *fdt;
+	struct fdt_node n;
+
+	/* Get the memory map from the FDT. */
+	fdt = fdt_map(plat_get_fdt_addr(), &n, ppool);
+	if (!fdt) {
+		return;
+	}
+
+	if (!fdt_find_child(&n, "")) {
+		dlog("Unable to find FDT root node.\n");
+		goto out_unmap_fdt;
+	}
+
+	fdt_find_initrd(&n, begin, end);
+
+out_unmap_fdt:
+	if (!fdt_unmap(fdt, ppool)) {
+		dlog("Unable to unmap fdt.");
+	}
+}
diff --git a/linux_fdt/plat_entry.S b/linux_fdt/plat_entry.S
new file mode 100644
index 0000000..95faec3
--- /dev/null
+++ b/linux_fdt/plat_entry.S
@@ -0,0 +1,25 @@
+/*
+ * Copyright 2018 The Hafnium Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+.section .init.plat_entry, "ax"
+.global plat_entry
+plat_entry:
+	/* Save the FDT to a global variable. */
+	adrp x25, plat_fdt_addr
+	add x25, x25, :lo12:plat_fdt_addr
+	str x0, [x25]
+
+	ret