dtc: Rework handling of boot_cpuid_phys

Currently, dtc will put the nonsense value 0xfeedbeef into the
boot_cpuid_phys field of an output blob, unless explicitly given
another value with the -b command line option.  As well as being a
totally unuseful default value, this also means that dtc won't
properly preserve the boot_cpuid_phys field in -I dtb -O dtb mode.

This patch reworks things to improve the boot_cpuid handling.  The new
semantics are that the output's boot_cpuid_phys value is:
	the value given on the command line if -b is used
otherwise
	the value from the input, if in -I dtb mode
otherwise
	0

Implementation-wise we do the following:
	- boot_cpuid_phys is added to struct boot_info, so that
structure now contains all of the blob's semantic information.
	- dt_to_blob() and dt_to_asm() output the cpuid given in
boot_info
	- dt_from_blob() fills in boot_info based on the input blob
	- The other dt_from_*() functions just record 0, but we can
change this easily if e.g. we invent a way of specifying the boot cpu
in the source format.
	- main() overrides the cpuid in the boot_info between input
and output if -b is given

We add some testcases to check this new behaviour.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

tests/boot-cpuid.c

@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2008 David Gibson, IBM Corporation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdint.h>
+
+#include <fdt.h>
+#include <libfdt.h>
+
+#include "tests.h"
+#include "testdata.h"
+
+int main(int argc, char *argv[])
+{
+	void *fdt;
+	uint32_t cpuid;
+
+	test_init(argc, argv);
+
+	if (argc != 3)
+		CONFIG("Usage: %s <dtb file> <cpuid>", argv[0]);
+
+	fdt = load_blob(argv[1]);
+	cpuid = strtoul(argv[2], NULL, 0);
+
+	if (fdt_boot_cpuid_phys(fdt) != cpuid)
+		FAIL("Incorrect boot_cpuid_phys (0x%x instead of 0x%x)",
+		     fdt_boot_cpuid_phys(fdt), cpuid);
+
+	PASS();
+}