libfdt: Use void * to refer to device tree blobs
At present, the blob containing a device tree is passed to the various
fdt_*() functions as a (struct fdt_header *) i.e. a pointer to the
header structure at the beginning of the blob.
This patch changes all the functions so that they instead take a (void
*) pointing to the blob. Under some circumstances can avoid the need
for the caller to cast a blob pointer into a (struct fdt_header *)
before passing it to the fdt_*() functions.
Using a (void *) also reduce the temptation for users of the library
to directly dereference toe (struct fdt_header *) to access header
fields. Instead they must use the fdt_get_header() or
fdt_set_header() macros, or the fdt_magic(), fdt_totalsize()
etc. wrappers around them which are safer, since they will always
handle endian conversion.
With this change, the whole-tree moving, or manipulating functions:
fdt_move(), fdt_open_into() and fdt_pack() no longer need to return a
pointer to the "new" tree. The given (void *) buffer pointer they
take can instead be used directly by the caller as the new tree.
Those functions are thus changed to instead return an error code
(which in turn reduces the number of functions using the ugly encoding
of error values into pointers).
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
diff --git a/libfdt_internal.h b/libfdt_internal.h
index d8c7551..9cb8a8c 100644
--- a/libfdt_internal.h
+++ b/libfdt_internal.h
@@ -26,10 +26,10 @@
#define memeq(p, q, n) (memcmp((p), (q), (n)) == 0)
#define streq(p, q) (strcmp((p), (q)) == 0)
-int _fdt_check_header(const struct fdt_header *fdt);
-uint32_t _fdt_next_tag(const struct fdt_header *fdt, int startoffset, int *nextoffset);
+int _fdt_check_header(const void *fdt);
+uint32_t _fdt_next_tag(const void *fdt, int startoffset, int *nextoffset);
const char *_fdt_find_string(const char *strtab, int tabsize, const char *s);
-int _fdt_node_end_offset(struct fdt_header *fdt, int nodeoffset);
+int _fdt_node_end_offset(void *fdt, int nodeoffset);
static inline void *_fdt_offset_ptr(const struct fdt_header *fdt, int offset)
{