libfdt: Import libfdt source (1 of 2)

This adds the applicable libfdt source files (unmodified) and a README
to explain where the source came from.

1 files changed, 124 insertions, 0 deletions

diff --git a/libfdt/fdt.c b/libfdt/fdt.c
new file mode 100644
index 000000000..772da46a7
--- /dev/null
+++ b/libfdt/fdt.c
@@ -0,0 +1,124 @@
+/*
+ * libfdt - Flat Device Tree manipulation
+ * Copyright (C) 2006 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 "libfdt_env.h"
+
+#include <fdt.h>
+#include <libfdt.h>
+
+#include "libfdt_internal.h"
+
+int _fdt_check_header(const void *fdt)
+{
+	if (fdt_magic(fdt) == FDT_MAGIC) {
+		/* Complete tree */
+		if (fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
+			return -FDT_ERR_BADVERSION;
+		if (fdt_last_comp_version(fdt) > FDT_LAST_SUPPORTED_VERSION)
+			return -FDT_ERR_BADVERSION;
+	} else if (fdt_magic(fdt) == SW_MAGIC) {
+		/* Unfinished sequential-write blob */
+		if (fdt_size_dt_struct(fdt) == 0)
+			return -FDT_ERR_BADSTATE;
+	} else {
+		return -FDT_ERR_BADMAGIC;
+	}
+
+	return 0;
+}
+
+void *fdt_offset_ptr(const void *fdt, int offset, int len)
+{
+	void *p;
+
+	if (fdt_version(fdt) >= 0x11)
+		if (((offset + len) < offset)
+		    || ((offset + len) > fdt_size_dt_struct(fdt)))
+			return NULL;
+
+	p = _fdt_offset_ptr(fdt, offset);
+
+	if (p + len < p)
+		return NULL;
+	return p;
+}
+
+uint32_t _fdt_next_tag(const void *fdt, int offset, int *nextoffset)
+{
+	const uint32_t *tagp, *lenp;
+	uint32_t tag;
+	const char *p;
+
+	if (offset % FDT_TAGSIZE)
+		return -1;
+
+	tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE);
+	if (! tagp)
+		return FDT_END; /* premature end */
+	tag = fdt32_to_cpu(*tagp);
+	offset += FDT_TAGSIZE;
+
+	switch (tag) {
+	case FDT_BEGIN_NODE:
+		/* skip name */
+		do {
+			p = fdt_offset_ptr(fdt, offset++, 1);
+		} while (p && (*p != '\0'));
+		if (! p)
+			return FDT_END;
+		break;
+	case FDT_PROP:
+		lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp));
+		if (! lenp)
+			return FDT_END;
+		/* skip name offset, length and value */
+		offset += 2*FDT_TAGSIZE + fdt32_to_cpu(*lenp);
+		break;
+	}
+
+	if (nextoffset)
+		*nextoffset = ALIGN(offset, FDT_TAGSIZE);
+
+	return tag;
+}
+
+const char *_fdt_find_string(const char *strtab, int tabsize, const char *s)
+{
+	int len = strlen(s) + 1;
+	const char *last = strtab + tabsize - len;
+	const char *p;
+
+	for (p = strtab; p <= last; p++)
+		if (memeq(p, s, len))
+			return p;
+	return NULL;
+}
+
+int fdt_move(const void *fdt, void *buf, int bufsize)
+{
+	int err = _fdt_check_header(fdt);
+
+	if (err)
+		return err;
+
+	if (fdt_totalsize(fdt) > bufsize)
+		return -FDT_ERR_NOSPACE;
+
+	memmove(buf, fdt, fdt_totalsize(fdt));
+	return 0;
+}