1 // SPDX-License-Identifier: GPL-2.0
4 * Masami Hiramatsu <mhiramat@kernel.org>
8 #include <linux/bootconfig.h>
10 #include <linux/ctype.h>
11 #include <linux/errno.h>
12 #include <linux/kernel.h>
13 #include <linux/memblock.h>
14 #include <linux/string.h>
16 #ifdef CONFIG_BOOT_CONFIG_EMBED
17 /* embedded_bootconfig_data is defined in bootconfig-data.S */
18 extern __visible
const char embedded_bootconfig_data
[];
19 extern __visible
const char embedded_bootconfig_data_end
[];
21 const char * __init
xbc_get_embedded_bootconfig(size_t *size
)
23 *size
= embedded_bootconfig_data_end
- embedded_bootconfig_data
;
24 return (*size
) ? embedded_bootconfig_data
: NULL
;
28 #else /* !__KERNEL__ */
30 * NOTE: This is only for tools/bootconfig, because tools/bootconfig will
31 * run the parser sanity test.
32 * This does NOT mean lib/bootconfig.c is available in the user space.
33 * However, if you change this file, please make sure the tools/bootconfig
34 * has no issue on building and running.
36 #include <linux/bootconfig.h>
40 * Extra Boot Config (XBC) is given as tree-structured ascii text of
41 * key-value pairs on memory.
42 * xbc_parse() parses the text to build a simple tree. Each tree node is
43 * simply a key word or a value. A key node may have a next key node or/and
44 * a child node (both key and value). A value node may have a next value
48 static struct xbc_node
*xbc_nodes __initdata
;
49 static int xbc_node_num __initdata
;
50 static char *xbc_data __initdata
;
51 static size_t xbc_data_size __initdata
;
52 static struct xbc_node
*last_parent __initdata
;
53 static const char *xbc_err_msg __initdata
;
54 static int xbc_err_pos __initdata
;
55 static int open_brace
[XBC_DEPTH_MAX
] __initdata
;
56 static int brace_index __initdata
;
59 static inline void * __init
xbc_alloc_mem(size_t size
)
61 return memblock_alloc(size
, SMP_CACHE_BYTES
);
64 static inline void __init
xbc_free_mem(void *addr
, size_t size
)
66 memblock_free(addr
, size
);
69 #else /* !__KERNEL__ */
71 static inline void *xbc_alloc_mem(size_t size
)
76 static inline void xbc_free_mem(void *addr
, size_t size
)
82 * xbc_get_info() - Get the information of loaded boot config
83 * @node_size: A pointer to store the number of nodes.
84 * @data_size: A pointer to store the size of bootconfig data.
86 * Get the number of used nodes in @node_size if it is not NULL,
87 * and the size of bootconfig data in @data_size if it is not NULL.
88 * Return 0 if the boot config is initialized, or return -ENODEV.
90 int __init
xbc_get_info(int *node_size
, size_t *data_size
)
96 *node_size
= xbc_node_num
;
98 *data_size
= xbc_data_size
;
102 static int __init
xbc_parse_error(const char *msg
, const char *p
)
105 xbc_err_pos
= (int)(p
- xbc_data
);
111 * xbc_root_node() - Get the root node of extended boot config
113 * Return the address of root node of extended boot config. If the
114 * extended boot config is not initiized, return NULL.
116 struct xbc_node
* __init
xbc_root_node(void)
118 if (unlikely(!xbc_data
))
125 * xbc_node_index() - Get the index of XBC node
126 * @node: A target node of getting index.
128 * Return the index number of @node in XBC node list.
130 int __init
xbc_node_index(struct xbc_node
*node
)
132 return node
- &xbc_nodes
[0];
136 * xbc_node_get_parent() - Get the parent XBC node
137 * @node: An XBC node.
139 * Return the parent node of @node. If the node is top node of the tree,
142 struct xbc_node
* __init
xbc_node_get_parent(struct xbc_node
*node
)
144 return node
->parent
== XBC_NODE_MAX
? NULL
: &xbc_nodes
[node
->parent
];
148 * xbc_node_get_child() - Get the child XBC node
149 * @node: An XBC node.
151 * Return the first child node of @node. If the node has no child, return
154 struct xbc_node
* __init
xbc_node_get_child(struct xbc_node
*node
)
156 return node
->child
? &xbc_nodes
[node
->child
] : NULL
;
160 * xbc_node_get_next() - Get the next sibling XBC node
161 * @node: An XBC node.
163 * Return the NEXT sibling node of @node. If the node has no next sibling,
164 * return NULL. Note that even if this returns NULL, it doesn't mean @node
165 * has no siblings. (You also has to check whether the parent's child node
168 struct xbc_node
* __init
xbc_node_get_next(struct xbc_node
*node
)
170 return node
->next
? &xbc_nodes
[node
->next
] : NULL
;
174 * xbc_node_get_data() - Get the data of XBC node
175 * @node: An XBC node.
177 * Return the data (which is always a null terminated string) of @node.
178 * If the node has invalid data, warn and return NULL.
180 const char * __init
xbc_node_get_data(struct xbc_node
*node
)
182 int offset
= node
->data
& ~XBC_VALUE
;
184 if (WARN_ON(offset
>= xbc_data_size
))
187 return xbc_data
+ offset
;
191 xbc_node_match_prefix(struct xbc_node
*node
, const char **prefix
)
193 const char *p
= xbc_node_get_data(node
);
196 if (strncmp(*prefix
, p
, len
))
210 * xbc_node_find_subkey() - Find a subkey node which matches given key
211 * @parent: An XBC node.
212 * @key: A key string.
214 * Search a key node under @parent which matches @key. The @key can contain
215 * several words jointed with '.'. If @parent is NULL, this searches the
216 * node from whole tree. Return NULL if no node is matched.
218 struct xbc_node
* __init
219 xbc_node_find_subkey(struct xbc_node
*parent
, const char *key
)
221 struct xbc_node
*node
;
224 node
= xbc_node_get_subkey(parent
);
226 node
= xbc_root_node();
228 while (node
&& xbc_node_is_key(node
)) {
229 if (!xbc_node_match_prefix(node
, &key
))
230 node
= xbc_node_get_next(node
);
231 else if (*key
!= '\0')
232 node
= xbc_node_get_subkey(node
);
241 * xbc_node_find_value() - Find a value node which matches given key
242 * @parent: An XBC node.
243 * @key: A key string.
244 * @vnode: A container pointer of found XBC node.
246 * Search a value node under @parent whose (parent) key node matches @key,
247 * store it in *@vnode, and returns the value string.
248 * The @key can contain several words jointed with '.'. If @parent is NULL,
249 * this searches the node from whole tree. Return the value string if a
250 * matched key found, return NULL if no node is matched.
251 * Note that this returns 0-length string and stores NULL in *@vnode if the
252 * key has no value. And also it will return the value of the first entry if
253 * the value is an array.
256 xbc_node_find_value(struct xbc_node
*parent
, const char *key
,
257 struct xbc_node
**vnode
)
259 struct xbc_node
*node
= xbc_node_find_subkey(parent
, key
);
261 if (!node
|| !xbc_node_is_key(node
))
264 node
= xbc_node_get_child(node
);
265 if (node
&& !xbc_node_is_value(node
))
271 return node
? xbc_node_get_data(node
) : "";
275 * xbc_node_compose_key_after() - Compose partial key string of the XBC node
276 * @root: Root XBC node
277 * @node: Target XBC node.
278 * @buf: A buffer to store the key.
279 * @size: The size of the @buf.
281 * Compose the partial key of the @node into @buf, which is starting right
282 * after @root (@root is not included.) If @root is NULL, this returns full
283 * key words of @node.
284 * Returns the total length of the key stored in @buf. Returns -EINVAL
285 * if @node is NULL or @root is not the ancestor of @node or @root is @node,
286 * or returns -ERANGE if the key depth is deeper than max depth.
287 * This is expected to be used with xbc_find_node() to list up all (child)
288 * keys under given key.
290 int __init
xbc_node_compose_key_after(struct xbc_node
*root
,
291 struct xbc_node
*node
,
292 char *buf
, size_t size
)
294 uint16_t keys
[XBC_DEPTH_MAX
];
295 int depth
= 0, ret
= 0, total
= 0;
297 if (!node
|| node
== root
)
300 if (xbc_node_is_value(node
))
301 node
= xbc_node_get_parent(node
);
303 while (node
&& node
!= root
) {
304 keys
[depth
++] = xbc_node_index(node
);
305 if (depth
== XBC_DEPTH_MAX
)
307 node
= xbc_node_get_parent(node
);
312 while (--depth
>= 0) {
313 node
= xbc_nodes
+ keys
[depth
];
314 ret
= snprintf(buf
, size
, "%s%s", xbc_node_get_data(node
),
331 * xbc_node_find_next_leaf() - Find the next leaf node under given node
332 * @root: An XBC root node
333 * @node: An XBC node which starts from.
335 * Search the next leaf node (which means the terminal key node) of @node
336 * under @root node (including @root node itself).
337 * Return the next node or NULL if next leaf node is not found.
339 struct xbc_node
* __init
xbc_node_find_next_leaf(struct xbc_node
*root
,
340 struct xbc_node
*node
)
342 struct xbc_node
*next
;
344 if (unlikely(!xbc_data
))
347 if (!node
) { /* First try */
352 /* Leaf node may have a subkey */
353 next
= xbc_node_get_subkey(node
);
359 if (node
== root
) /* @root was a leaf, no child node. */
362 while (!node
->next
) {
363 node
= xbc_node_get_parent(node
);
366 /* User passed a node which is not uder parent */
370 node
= xbc_node_get_next(node
);
374 while (node
&& !xbc_node_is_leaf(node
))
375 node
= xbc_node_get_child(node
);
381 * xbc_node_find_next_key_value() - Find the next key-value pair nodes
382 * @root: An XBC root node
383 * @leaf: A container pointer of XBC node which starts from.
385 * Search the next leaf node (which means the terminal key node) of *@leaf
386 * under @root node. Returns the value and update *@leaf if next leaf node
387 * is found, or NULL if no next leaf node is found.
388 * Note that this returns 0-length string if the key has no value, or
389 * the value of the first entry if the value is an array.
391 const char * __init
xbc_node_find_next_key_value(struct xbc_node
*root
,
392 struct xbc_node
**leaf
)
394 /* tip must be passed */
398 *leaf
= xbc_node_find_next_leaf(root
, *leaf
);
402 return xbc_node_get_data(xbc_node_get_child(*leaf
));
404 return ""; /* No value key */
407 /* XBC parse and tree build */
409 static int __init
xbc_init_node(struct xbc_node
*node
, char *data
, uint32_t flag
)
411 unsigned long offset
= data
- xbc_data
;
413 if (WARN_ON(offset
>= XBC_DATA_MAX
))
416 node
->data
= (uint16_t)offset
| flag
;
423 static struct xbc_node
* __init
xbc_add_node(char *data
, uint32_t flag
)
425 struct xbc_node
*node
;
427 if (xbc_node_num
== XBC_NODE_MAX
)
430 node
= &xbc_nodes
[xbc_node_num
++];
431 if (xbc_init_node(node
, data
, flag
) < 0)
437 static inline __init
struct xbc_node
*xbc_last_sibling(struct xbc_node
*node
)
440 node
= xbc_node_get_next(node
);
445 static inline __init
struct xbc_node
*xbc_last_child(struct xbc_node
*node
)
448 node
= xbc_node_get_child(node
);
453 static struct xbc_node
* __init
__xbc_add_sibling(char *data
, uint32_t flag
, bool head
)
455 struct xbc_node
*sib
, *node
= xbc_add_node(data
, flag
);
459 /* Ignore @head in this case */
460 node
->parent
= XBC_NODE_MAX
;
461 sib
= xbc_last_sibling(xbc_nodes
);
462 sib
->next
= xbc_node_index(node
);
464 node
->parent
= xbc_node_index(last_parent
);
465 if (!last_parent
->child
|| head
) {
466 node
->next
= last_parent
->child
;
467 last_parent
->child
= xbc_node_index(node
);
469 sib
= xbc_node_get_child(last_parent
);
470 sib
= xbc_last_sibling(sib
);
471 sib
->next
= xbc_node_index(node
);
475 xbc_parse_error("Too many nodes", data
);
480 static inline struct xbc_node
* __init
xbc_add_sibling(char *data
, uint32_t flag
)
482 return __xbc_add_sibling(data
, flag
, false);
485 static inline struct xbc_node
* __init
xbc_add_head_sibling(char *data
, uint32_t flag
)
487 return __xbc_add_sibling(data
, flag
, true);
490 static inline __init
struct xbc_node
*xbc_add_child(char *data
, uint32_t flag
)
492 struct xbc_node
*node
= xbc_add_sibling(data
, flag
);
500 static inline __init
bool xbc_valid_keyword(char *key
)
505 while (isalnum(*key
) || *key
== '-' || *key
== '_')
511 static char *skip_comment(char *p
)
515 ret
= strchr(p
, '\n');
524 static char *skip_spaces_until_newline(char *p
)
526 while (isspace(*p
) && *p
!= '\n')
531 static int __init
__xbc_open_brace(char *p
)
533 /* Push the last key as open brace */
534 open_brace
[brace_index
++] = xbc_node_index(last_parent
);
535 if (brace_index
>= XBC_DEPTH_MAX
)
536 return xbc_parse_error("Exceed max depth of braces", p
);
541 static int __init
__xbc_close_brace(char *p
)
544 if (!last_parent
|| brace_index
< 0 ||
545 (open_brace
[brace_index
] != xbc_node_index(last_parent
)))
546 return xbc_parse_error("Unexpected closing brace", p
);
548 if (brace_index
== 0)
551 last_parent
= &xbc_nodes
[open_brace
[brace_index
- 1]];
557 * Return delimiter or error, no node added. As same as lib/cmdline.c,
558 * you can use " around spaces, but can't escape " for value.
560 static int __init
__xbc_parse_value(char **__v
, char **__n
)
570 if (*v
== '"' || *v
== '\'') {
576 if (!isprint(c
) && !isspace(c
))
577 return xbc_parse_error("Non printable value", p
);
583 p
= skip_spaces_until_newline(p
);
585 if (c
&& !strchr(",;\n#}", c
))
586 return xbc_parse_error("No value delimiter", p
);
591 if (strchr(",;\n#}", c
)) {
598 return xbc_parse_error("No closing quotes", p
);
601 c
= '\n'; /* A comment must be treated as a newline */
609 static int __init
xbc_parse_array(char **__v
)
611 struct xbc_node
*node
;
615 if (last_parent
->child
)
616 last_parent
= xbc_node_get_child(last_parent
);
619 c
= __xbc_parse_value(__v
, &next
);
623 node
= xbc_add_child(*__v
, XBC_VALUE
);
634 struct xbc_node
*find_match_node(struct xbc_node
*node
, char *k
)
637 if (!strcmp(xbc_node_get_data(node
), k
))
639 node
= xbc_node_get_next(node
);
644 static int __init
__xbc_add_key(char *k
)
646 struct xbc_node
*node
, *child
;
648 if (!xbc_valid_keyword(k
))
649 return xbc_parse_error("Invalid keyword", k
);
651 if (unlikely(xbc_node_num
== 0))
654 if (!last_parent
) /* the first level */
655 node
= find_match_node(xbc_nodes
, k
);
657 child
= xbc_node_get_child(last_parent
);
658 /* Since the value node is the first child, skip it. */
659 if (child
&& xbc_node_is_value(child
))
660 child
= xbc_node_get_next(child
);
661 node
= find_match_node(child
, k
);
668 node
= xbc_add_child(k
, XBC_KEY
);
675 static int __init
__xbc_parse_keys(char *k
)
681 while ((p
= strchr(k
, '.'))) {
683 ret
= __xbc_add_key(k
);
689 return __xbc_add_key(k
);
692 static int __init
xbc_parse_kv(char **k
, char *v
, int op
)
694 struct xbc_node
*prev_parent
= last_parent
;
695 struct xbc_node
*child
;
699 ret
= __xbc_parse_keys(*k
);
703 c
= __xbc_parse_value(&v
, &next
);
707 child
= xbc_node_get_child(last_parent
);
708 if (child
&& xbc_node_is_value(child
)) {
710 return xbc_parse_error("Value is redefined", v
);
712 unsigned short nidx
= child
->next
;
714 xbc_init_node(child
, v
, XBC_VALUE
);
715 child
->next
= nidx
; /* keep subkeys */
719 last_parent
= xbc_last_child(child
);
721 /* The value node should always be the first child */
722 if (!xbc_add_head_sibling(v
, XBC_VALUE
))
726 if (c
== ',') { /* Array */
727 c
= xbc_parse_array(&next
);
732 last_parent
= prev_parent
;
735 ret
= __xbc_close_brace(next
- 1);
745 static int __init
xbc_parse_key(char **k
, char *n
)
747 struct xbc_node
*prev_parent
= last_parent
;
752 ret
= __xbc_parse_keys(*k
);
755 last_parent
= prev_parent
;
762 static int __init
xbc_open_brace(char **k
, char *n
)
766 ret
= __xbc_parse_keys(*k
);
771 return __xbc_open_brace(n
- 1);
774 static int __init
xbc_close_brace(char **k
, char *n
)
778 ret
= xbc_parse_key(k
, n
);
781 /* k is updated in xbc_parse_key() */
783 return __xbc_close_brace(n
- 1);
786 static int __init
xbc_verify_tree(void)
788 int i
, depth
, len
, wlen
;
789 struct xbc_node
*n
, *m
;
793 n
= &xbc_nodes
[open_brace
[brace_index
]];
794 return xbc_parse_error("Brace is not closed",
795 xbc_node_get_data(n
));
799 if (xbc_node_num
== 0) {
800 xbc_parse_error("Empty config", xbc_data
);
804 for (i
= 0; i
< xbc_node_num
; i
++) {
805 if (xbc_nodes
[i
].next
> xbc_node_num
) {
806 return xbc_parse_error("No closing brace",
807 xbc_node_get_data(xbc_nodes
+ i
));
811 /* Key tree limitation check */
817 wlen
= strlen(xbc_node_get_data(n
)) + 1;
819 if (len
> XBC_KEYLEN_MAX
)
820 return xbc_parse_error("Too long key length",
821 xbc_node_get_data(n
));
823 m
= xbc_node_get_child(n
);
824 if (m
&& xbc_node_is_key(m
)) {
827 if (depth
> XBC_DEPTH_MAX
)
828 return xbc_parse_error("Too many key words",
829 xbc_node_get_data(n
));
833 m
= xbc_node_get_next(n
);
835 n
= xbc_node_get_parent(n
);
838 len
-= strlen(xbc_node_get_data(n
)) + 1;
840 m
= xbc_node_get_next(n
);
848 /* Need to setup xbc_data and xbc_nodes before call this. */
849 static int __init
xbc_parse_tree(void)
857 q
= strpbrk(p
, "{}=+;:\n#");
861 ret
= xbc_parse_error("No delimiter", p
);
871 ret
= xbc_parse_error(c
== '+' ?
872 "Wrong '+' operator" :
873 "Wrong ':' operator",
879 ret
= xbc_parse_kv(&p
, q
, c
);
882 ret
= xbc_open_brace(&p
, q
);
889 ret
= xbc_parse_key(&p
, q
);
892 ret
= xbc_close_brace(&p
, q
);
901 * xbc_exit() - Clean up all parsed bootconfig
903 * This clears all data structures of parsed bootconfig on memory.
904 * If you need to reuse xbc_init() with new boot config, you can
907 void __init
xbc_exit(void)
909 xbc_free_mem(xbc_data
, xbc_data_size
);
913 xbc_free_mem(xbc_nodes
, sizeof(struct xbc_node
) * XBC_NODE_MAX
);
919 * xbc_init() - Parse given XBC file and build XBC internal tree
920 * @data: The boot config text original data
921 * @size: The size of @data
922 * @emsg: A pointer of const char * to store the error message
923 * @epos: A pointer of int to store the error position
925 * This parses the boot config text in @data. @size must be smaller
927 * Return the number of stored nodes (>0) if succeeded, or -errno
928 * if there is any error.
929 * In error cases, @emsg will be updated with an error message and
930 * @epos will be updated with the error position which is the byte offset
931 * of @buf. If the error is not a parser error, @epos will be -1.
933 int __init
xbc_init(const char *data
, size_t size
, const char **emsg
, int *epos
)
942 *emsg
= "Bootconfig is already initialized";
945 if (size
> XBC_DATA_MAX
|| size
== 0) {
947 *emsg
= size
? "Config data is too big" :
948 "Config data is empty";
952 xbc_data
= xbc_alloc_mem(size
+ 1);
955 *emsg
= "Failed to allocate bootconfig data";
958 memcpy(xbc_data
, data
, size
);
959 xbc_data
[size
] = '\0';
960 xbc_data_size
= size
+ 1;
962 xbc_nodes
= xbc_alloc_mem(sizeof(struct xbc_node
) * XBC_NODE_MAX
);
965 *emsg
= "Failed to allocate bootconfig nodes";
969 memset(xbc_nodes
, 0, sizeof(struct xbc_node
) * XBC_NODE_MAX
);
971 ret
= xbc_parse_tree();
973 ret
= xbc_verify_tree();