sandbox: Support setting up the other FDT for testing

Provide a way to copy over the 'other' FDT when running tests. This loads
it and allocates memory for the copy, if not done already, then does the
copy.

Avoid using U-Boot's malloc() pool for these copies, at least for now,
since they are part of the test system.

Tidy up the cpu.c header files while here.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/sandbox/cpu/cpu.c b/arch/sandbox/cpu/cpu.c
index d077948..636d354 100644
--- a/arch/sandbox/cpu/cpu.c
+++ b/arch/sandbox/cpu/cpu.c
@@ -3,19 +3,22 @@
  * Copyright (c) 2011 The Chromium OS Authors.
  */
 
+#define LOG_CATEGORY	LOGC_SANDBOX
+
 #include <common.h>
 #include <bootstage.h>
 #include <cpu_func.h>
 #include <errno.h>
 #include <log.h>
-#include <asm/global_data.h>
-#include <linux/delay.h>
-#include <linux/libfdt.h>
 #include <os.h>
+#include <asm/global_data.h>
 #include <asm/io.h>
 #include <asm/malloc.h>
 #include <asm/setjmp.h>
 #include <asm/state.h>
+#include <dm/ofnode.h>
+#include <linux/delay.h>
+#include <linux/libfdt.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -373,3 +376,28 @@
 
 	return (count - base_count) / 1000;
 }
+
+int sandbox_load_other_fdt(void **fdtp, int *sizep)
+{
+	const char *orig;
+	int ret, size;
+	void *fdt = *fdtp;
+
+	ret = state_load_other_fdt(&orig, &size);
+	if (ret) {
+		log_err("Cannot read other FDT\n");
+		return log_msg_ret("ld", ret);
+	}
+
+	if (!*fdtp) {
+		fdt = os_malloc(size);
+		if (!fdt)
+			return log_msg_ret("mem", -ENOMEM);
+		*sizep = size;
+	}
+
+	memcpy(fdt, orig, *sizep);
+	*fdtp = fdt;
+
+	return 0;
+}
diff --git a/arch/sandbox/include/asm/test.h b/arch/sandbox/include/asm/test.h
index 53a036b..0406085 100644
--- a/arch/sandbox/include/asm/test.h
+++ b/arch/sandbox/include/asm/test.h
@@ -11,6 +11,8 @@
 #include <video.h>
 #include <pci_ids.h>
 
+struct unit_test_state;
+
 /* The sandbox driver always permits an I2C device with this address */
 #define SANDBOX_I2C_TEST_ADDR		0x59
 
@@ -315,4 +317,21 @@
  */
 void sandbox_set_fake_efi_mgr_dev(struct udevice *dev, bool fake_dev);
 
+/**
+ * sandbox_load_other_fdt() - load the 'other' FDT into the test state
+ *
+ * This copies the other.dtb file into the test state, so that a fresh version
+ * can be used for a test that is about to run.
+ *
+ * If @uts->other_fdt is NULL, as it is when first set up, this allocates a
+ * buffer for the other FDT and sets @uts->other_fdt_size to its size.
+ *
+ * In any case, the other FDT is copied from the sandbox state into
+ * @uts->other_fdt ready for use.
+ *
+ * @uts: Unit test state
+ * @return 0 if OK, -ve on error
+ */
+int sandbox_load_other_fdt(void **fdtp, int *sizep);
+
 #endif