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git.ipfire.org Git - thirdparty/u-boot.git/blob - lib/of_live.c
1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
4 * benh@kernel.crashing.org
6 * Based on parts of drivers/of/fdt.c from Linux v4.9
7 * Modifications for U-Boot
8 * Copyright (c) 2017 Google, Inc
12 #include <linux/libfdt.h>
15 #include <dm/of_access.h>
16 #include <linux/err.h>
18 static void *unflatten_dt_alloc(void **mem
, unsigned long size
,
23 *mem
= PTR_ALIGN(*mem
, align
);
31 * unflatten_dt_node() - Alloc and populate a device_node from the flat tree
32 * @blob: The parent device tree blob
33 * @mem: Memory chunk to use for allocating device nodes and properties
34 * @poffset: pointer to node in flat tree
35 * @dad: Parent struct device_node
36 * @nodepp: The device_node tree created by the call
37 * @fpsize: Size of the node path up at t05he current depth.
38 * @dryrun: If true, do not allocate device nodes but still calculate needed
41 static void *unflatten_dt_node(const void *blob
, void *mem
, int *poffset
,
42 struct device_node
*dad
,
43 struct device_node
**nodepp
,
44 unsigned long fpsize
, bool dryrun
)
47 struct device_node
*np
;
48 struct property
*pp
, **prev_pp
= NULL
;
58 pathp
= fdt_get_name(blob
, *poffset
, &l
);
65 * version 0x10 has a more compact unit name here instead of the full
66 * path. we accumulate the full path size using "fpsize", we'll rebuild
67 * it later. We detect this because the first character of the name is
70 if ((*pathp
) != '/') {
74 * root node: special case. fpsize accounts for path
75 * plus terminating zero. root node only has '/', so
76 * fpsize should be 2, but we want to avoid the first
77 * level nodes to have two '/' so we use fpsize 1 here
85 * account for '/' and path size minus terminal 0
93 np
= unflatten_dt_alloc(&mem
, sizeof(struct device_node
) + allocl
,
94 __alignof__(struct device_node
));
98 fn
= (char *)np
+ sizeof(*np
);
101 /* rebuild full path for new format */
102 if (dad
&& dad
->parent
) {
103 strcpy(fn
, dad
->full_name
);
105 if ((strlen(fn
) + l
+ 1) != allocl
) {
106 debug("%s: p: %d, l: %d, a: %d\n",
107 pathp
, (int)strlen(fn
), l
,
115 memcpy(fn
, pathp
, l
);
117 prev_pp
= &np
->properties
;
120 np
->sibling
= dad
->child
;
124 /* process properties */
125 for (offset
= fdt_first_property_offset(blob
, *poffset
);
127 (offset
= fdt_next_property_offset(blob
, offset
))) {
131 p
= fdt_getprop_by_offset(blob
, offset
, &pname
, &sz
);
133 offset
= -FDT_ERR_INTERNAL
;
138 debug("Can't find property name in list !\n");
141 if (strcmp(pname
, "name") == 0)
143 pp
= unflatten_dt_alloc(&mem
, sizeof(struct property
),
144 __alignof__(struct property
));
147 * We accept flattened tree phandles either in
148 * ePAPR-style "phandle" properties, or the
149 * legacy "linux,phandle" properties. If both
150 * appear and have different values, things
151 * will get weird. Don't do that. */
152 if ((strcmp(pname
, "phandle") == 0) ||
153 (strcmp(pname
, "linux,phandle") == 0)) {
154 if (np
->phandle
== 0)
155 np
->phandle
= be32_to_cpup(p
);
158 * And we process the "ibm,phandle" property
159 * used in pSeries dynamic device tree
161 if (strcmp(pname
, "ibm,phandle") == 0)
162 np
->phandle
= be32_to_cpup(p
);
163 pp
->name
= (char *)pname
;
165 pp
->value
= (__be32
*)p
;
171 * with version 0x10 we may not have the name property, recreate
172 * it here from the unit name if absent
175 const char *p1
= pathp
, *ps
= pathp
, *pa
= NULL
;
188 pp
= unflatten_dt_alloc(&mem
, sizeof(struct property
) + sz
,
189 __alignof__(struct property
));
196 memcpy(pp
->value
, ps
, sz
- 1);
197 ((char *)pp
->value
)[sz
- 1] = 0;
198 debug("fixed up name for %s -> %s\n", pathp
,
204 np
->name
= of_get_property(np
, "name", NULL
);
205 np
->type
= of_get_property(np
, "device_type", NULL
);
210 np
->type
= "<NULL>"; }
213 *poffset
= fdt_next_node(blob
, *poffset
, &depth
);
216 while (*poffset
> 0 && depth
> old_depth
) {
217 mem
= unflatten_dt_node(blob
, mem
, poffset
, np
, NULL
,
223 if (*poffset
< 0 && *poffset
!= -FDT_ERR_NOTFOUND
) {
224 debug("unflatten: error %d processing FDT\n", *poffset
);
229 * Reverse the child list. Some drivers assumes node order matches .dts
232 if (!dryrun
&& np
->child
) {
233 struct device_node
*child
= np
->child
;
236 struct device_node
*next
= child
->sibling
;
238 child
->sibling
= np
->child
;
251 * unflatten_device_tree() - create tree of device_nodes from flat blob
253 * unflattens a device-tree, creating the
254 * tree of struct device_node. It also fills the "name" and "type"
255 * pointers of the nodes so the normal device-tree walking functions
257 * @blob: The blob to expand
258 * @mynodes: The device_node tree created by the call
259 * @return 0 if OK, -ve on error
261 static int unflatten_device_tree(const void *blob
,
262 struct device_node
**mynodes
)
268 debug(" -> unflatten_device_tree()\n");
271 debug("No device tree pointer\n");
275 debug("Unflattening device tree:\n");
276 debug("magic: %08x\n", fdt_magic(blob
));
277 debug("size: %08x\n", fdt_totalsize(blob
));
278 debug("version: %08x\n", fdt_version(blob
));
280 if (fdt_check_header(blob
)) {
281 debug("Invalid device tree blob header\n");
285 /* First pass, scan for size */
287 size
= (unsigned long)unflatten_dt_node(blob
, NULL
, &start
, NULL
, NULL
,
291 size
= ALIGN(size
, 4);
293 debug(" size is %lx, allocating...\n", size
);
295 /* Allocate memory for the expanded device tree */
296 mem
= malloc(size
+ 4);
297 memset(mem
, '\0', size
);
299 *(__be32
*)(mem
+ size
) = cpu_to_be32(0xdeadbeef);
301 debug(" unflattening %p...\n", mem
);
303 /* Second pass, do actual unflattening */
305 unflatten_dt_node(blob
, mem
, &start
, NULL
, mynodes
, 0, false);
306 if (be32_to_cpup(mem
+ size
) != 0xdeadbeef) {
307 debug("End of tree marker overwritten: %08x\n",
308 be32_to_cpup(mem
+ size
));
312 debug(" <- unflatten_device_tree()\n");
317 int of_live_build(const void *fdt_blob
, struct device_node
**rootp
)
321 debug("%s: start\n", __func__
);
322 ret
= unflatten_device_tree(fdt_blob
, rootp
);
324 debug("Failed to create live tree: err=%d\n", ret
);
327 ret
= of_alias_scan();
329 debug("Failed to scan live tree aliases: err=%d\n", ret
);
332 debug("%s: stop\n", __func__
);