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.h b/libfdt.h
index cee2b3c..ed834bd 100644
--- a/libfdt.h
+++ b/libfdt.h
@@ -45,18 +45,23 @@
#define FDT_ERR_MAX 14
-#define fdt_magic(fdt) (fdt32_to_cpu(fdt->magic))
-#define fdt_totalsize(fdt) (fdt32_to_cpu(fdt->totalsize))
-#define fdt_off_dt_struct(fdt) (fdt32_to_cpu(fdt->off_dt_struct))
-#define fdt_off_dt_strings(fdt) (fdt32_to_cpu(fdt->off_dt_strings))
-#define fdt_off_mem_rsvmap(fdt) (fdt32_to_cpu(fdt->off_mem_rsvmap))
-#define fdt_version(fdt) (fdt32_to_cpu(fdt->version))
-#define fdt_last_comp_version(fdt) (fdt32_to_cpu(fdt->last_comp_version))
-#define fdt_boot_cpuid_phys(fdt) (fdt32_to_cpu(fdt->boot_cpuid_phys))
-#define fdt_size_dt_strings(fdt) (fdt32_to_cpu(fdt->size_dt_strings))
-#define fdt_size_dt_struct(fdt) (fdt32_to_cpu(fdt->size_dt_struct))
+#define fdt_get_header(fdt, field) \
+ (fdt32_to_cpu(((struct fdt_header *)(fdt))->field))
+#define fdt_magic(fdt) (fdt_get_header(fdt, magic))
+#define fdt_totalsize(fdt) (fdt_get_header(fdt, totalsize))
+#define fdt_off_dt_struct(fdt) (fdt_get_header(fdt, off_dt_struct))
+#define fdt_off_dt_strings(fdt) (fdt_get_header(fdt, off_dt_strings))
+#define fdt_off_mem_rsvmap(fdt) (fdt_get_header(fdt, off_mem_rsvmap))
+#define fdt_version(fdt) (fdt_get_header(fdt, version))
+#define fdt_last_comp_version(fdt) (fdt_get_header(fdt, last_comp_version))
+#define fdt_boot_cpuid_phys(fdt) (fdt_get_header(fdt, boot_cpuid_phys))
+#define fdt_size_dt_strings(fdt) (fdt_get_header(fdt, size_dt_strings))
+#define fdt_size_dt_struct(fdt) (fdt_get_header(fdt, size_dt_struct))
-void *fdt_offset_ptr(const struct fdt_header *fdt, int offset, int checklen);
+#define fdt_set_header(fdt, field, val) \
+ ((struct fdt_header *)(fdt))->field = cpu_to_fdt32(val)
+
+void *fdt_offset_ptr(const void *fdt, int offset, int checklen);
#define fdt_offset_ptr_typed(fdt, offset, var) \
((typeof(var))(fdt_offset_ptr((fdt), (offset), sizeof(*(var)))))
@@ -67,26 +72,24 @@
#define fdt_ptr_error(ptr) \
( (((long)(ptr) < 0) && ((long)(ptr) >= -FDT_ERR_MAX)) ? -(long)(ptr) : 0 )
-struct fdt_header *fdt_move(const struct fdt_header *fdt, void *buf, int bufsize);
+int fdt_move(const void *fdt, void *buf, int bufsize);
/* Read-only functions */
-char *fdt_string(const struct fdt_header *fdt, int stroffset);
+char *fdt_string(const void *fdt, int stroffset);
-int fdt_subnode_offset_namelen(const struct fdt_header *fdt, int parentoffset,
+int fdt_subnode_offset_namelen(const void *fdt, int parentoffset,
const char *name, int namelen);
-int fdt_subnode_offset(const struct fdt_header *fdt, int parentoffset,
- const char *name);
+int fdt_subnode_offset(const void *fdt, int parentoffset, const char *name);
-int fdt_path_offset(const struct fdt_header *fdt, const char *path);
+int fdt_path_offset(const void *fdt, const char *path);
-struct fdt_property *fdt_get_property(const struct fdt_header *fdt,
- int nodeoffset,
+struct fdt_property *fdt_get_property(const void *fdt, int nodeoffset,
const char *name, int *lenp);
-void *fdt_getprop(const struct fdt_header *fdt, int nodeoffset,
+void *fdt_getprop(const void *fdt, int nodeoffset,
const char *name, int *lenp);
/* Write-in-place functions */
-int fdt_setprop_inplace(struct fdt_header *fdt, int nodeoffset, const char *name,
+int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name,
const void *val, int len);
#define fdt_setprop_inplace_typed(fdt, nodeoffset, name, val) \
@@ -95,15 +98,15 @@
fdt_setprop_inplace(fdt, nodeoffset, name, &x, sizeof(x)); \
})
-int fdt_nop_property(struct fdt_header *fdt, int nodeoffset, const char *name);
-int fdt_nop_node(struct fdt_header *fdt, int nodeoffset);
+int fdt_nop_property(void *fdt, int nodeoffset, const char *name);
+int fdt_nop_node(void *fdt, int nodeoffset);
/* Sequential-write functions */
-struct fdt_header *fdt_create(void *buf, int bufsize);
-int fdt_add_reservemap_entry(struct fdt_header *fdt, uint64_t addr, uint64_t size);
-int fdt_finish_reservemap(struct fdt_header *fdt);
-int fdt_begin_node(struct fdt_header *fdt, const char *name);
-int fdt_property(struct fdt_header *fdt, const char *name, const void *val, int len);
+int fdt_create(void *buf, int bufsize);
+int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size);
+int fdt_finish_reservemap(void *fdt);
+int fdt_begin_node(void *fdt, const char *name);
+int fdt_property(void *fdt, const char *name, const void *val, int len);
#define fdt_property_typed(fdt, name, val) \
({ \
typeof(val) x = (val); \
@@ -111,14 +114,14 @@
})
#define fdt_property_string(fdt, name, str) \
fdt_property(fdt, name, str, strlen(str)+1)
-int fdt_end_node(struct fdt_header *fdt);
-int fdt_finish(struct fdt_header *fdt);
+int fdt_end_node(void *fdt);
+int fdt_finish(void *fdt);
/* Read-write functions */
-struct fdt_header *fdt_open_into(struct fdt_header *fdt, void *buf, int bufsize);
-struct fdt_header *fdt_pack(struct fdt_header *fdt);
+int fdt_open_into(void *fdt, void *buf, int bufsize);
+int fdt_pack(void *fdt);
-int fdt_setprop(struct fdt_header *fdt, int nodeoffset, const char *name,
+int fdt_setprop(void *fdt, int nodeoffset, const char *name,
const void *val, int len);
#define fdt_setprop_typed(fdt, nodeoffset, name, val) \
({ \
@@ -127,10 +130,10 @@
})
#define fdt_setprop_string(fdt, nodeoffset, name, str) \
fdt_setprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
-int fdt_delprop(struct fdt_header *fdt, int nodeoffset, const char *name);
-int fdt_add_subnode_namelen(struct fdt_header *fdt, int parentoffset,
+int fdt_delprop(void *fdt, int nodeoffset, const char *name);
+int fdt_add_subnode_namelen(void *fdt, int parentoffset,
const char *name, int namelen);
-int fdt_add_subnode(struct fdt_header *fdt, int parentoffset, const char *name);
-int fdt_del_node(struct fdt_header *fdt, int nodeoffset);
+int fdt_add_subnode(void *fdt, int parentoffset, const char *name);
+int fdt_del_node(void *fdt, int nodeoffset);
#endif /* _LIBFDT_H */