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
, bool early
)
67 memblock_free(addr
, size
);
69 memblock_free_late(__pa(addr
), size
);
72 #else /* !__KERNEL__ */
74 static inline void *xbc_alloc_mem(size_t size
)
79 static inline void xbc_free_mem(void *addr
, size_t size
, bool early
)
85 * xbc_get_info() - Get the information of loaded boot config
86 * @node_size: A pointer to store the number of nodes.
87 * @data_size: A pointer to store the size of bootconfig data.
89 * Get the number of used nodes in @node_size if it is not NULL,
90 * and the size of bootconfig data in @data_size if it is not NULL.
91 * Return 0 if the boot config is initialized, or return -ENODEV.
93 int __init
xbc_get_info(int *node_size
, size_t *data_size
)
99 *node_size
= xbc_node_num
;
101 *data_size
= xbc_data_size
;
105 static int __init
xbc_parse_error(const char *msg
, const char *p
)
108 xbc_err_pos
= (int)(p
- xbc_data
);
114 * xbc_root_node() - Get the root node of extended boot config
116 * Return the address of root node of extended boot config. If the
117 * extended boot config is not initiized, return NULL.
119 struct xbc_node
* __init
xbc_root_node(void)
121 if (unlikely(!xbc_data
))
128 * xbc_node_index() - Get the index of XBC node
129 * @node: A target node of getting index.
131 * Return the index number of @node in XBC node list.
133 int __init
xbc_node_index(struct xbc_node
*node
)
135 return node
- &xbc_nodes
[0];
139 * xbc_node_get_parent() - Get the parent XBC node
140 * @node: An XBC node.
142 * Return the parent node of @node. If the node is top node of the tree,
145 struct xbc_node
* __init
xbc_node_get_parent(struct xbc_node
*node
)
147 return node
->parent
== XBC_NODE_MAX
? NULL
: &xbc_nodes
[node
->parent
];
151 * xbc_node_get_child() - Get the child XBC node
152 * @node: An XBC node.
154 * Return the first child node of @node. If the node has no child, return
157 struct xbc_node
* __init
xbc_node_get_child(struct xbc_node
*node
)
159 return node
->child
? &xbc_nodes
[node
->child
] : NULL
;
163 * xbc_node_get_next() - Get the next sibling XBC node
164 * @node: An XBC node.
166 * Return the NEXT sibling node of @node. If the node has no next sibling,
167 * return NULL. Note that even if this returns NULL, it doesn't mean @node
168 * has no siblings. (You also has to check whether the parent's child node
171 struct xbc_node
* __init
xbc_node_get_next(struct xbc_node
*node
)
173 return node
->next
? &xbc_nodes
[node
->next
] : NULL
;
177 * xbc_node_get_data() - Get the data of XBC node
178 * @node: An XBC node.
180 * Return the data (which is always a null terminated string) of @node.
181 * If the node has invalid data, warn and return NULL.
183 const char * __init
xbc_node_get_data(struct xbc_node
*node
)
185 int offset
= node
->data
& ~XBC_VALUE
;
187 if (WARN_ON(offset
>= xbc_data_size
))
190 return xbc_data
+ offset
;
194 xbc_node_match_prefix(struct xbc_node
*node
, const char **prefix
)
196 const char *p
= xbc_node_get_data(node
);
199 if (strncmp(*prefix
, p
, len
))
213 * xbc_node_find_subkey() - Find a subkey node which matches given key
214 * @parent: An XBC node.
215 * @key: A key string.
217 * Search a key node under @parent which matches @key. The @key can contain
218 * several words jointed with '.'. If @parent is NULL, this searches the
219 * node from whole tree. Return NULL if no node is matched.
221 struct xbc_node
* __init
222 xbc_node_find_subkey(struct xbc_node
*parent
, const char *key
)
224 struct xbc_node
*node
;
227 node
= xbc_node_get_subkey(parent
);
229 node
= xbc_root_node();
231 while (node
&& xbc_node_is_key(node
)) {
232 if (!xbc_node_match_prefix(node
, &key
))
233 node
= xbc_node_get_next(node
);
234 else if (*key
!= '\0')
235 node
= xbc_node_get_subkey(node
);
244 * xbc_node_find_value() - Find a value node which matches given key
245 * @parent: An XBC node.
246 * @key: A key string.
247 * @vnode: A container pointer of found XBC node.
249 * Search a value node under @parent whose (parent) key node matches @key,
250 * store it in *@vnode, and returns the value string.
251 * The @key can contain several words jointed with '.'. If @parent is NULL,
252 * this searches the node from whole tree. Return the value string if a
253 * matched key found, return NULL if no node is matched.
254 * Note that this returns 0-length string and stores NULL in *@vnode if the
255 * key has no value. And also it will return the value of the first entry if
256 * the value is an array.
259 xbc_node_find_value(struct xbc_node
*parent
, const char *key
,
260 struct xbc_node
**vnode
)
262 struct xbc_node
*node
= xbc_node_find_subkey(parent
, key
);
264 if (!node
|| !xbc_node_is_key(node
))
267 node
= xbc_node_get_child(node
);
268 if (node
&& !xbc_node_is_value(node
))
274 return node
? xbc_node_get_data(node
) : "";
278 * xbc_node_compose_key_after() - Compose partial key string of the XBC node
279 * @root: Root XBC node
280 * @node: Target XBC node.
281 * @buf: A buffer to store the key.
282 * @size: The size of the @buf.
284 * Compose the partial key of the @node into @buf, which is starting right
285 * after @root (@root is not included.) If @root is NULL, this returns full
286 * key words of @node.
287 * Returns the total length of the key stored in @buf. Returns -EINVAL
288 * if @node is NULL or @root is not the ancestor of @node or @root is @node,
289 * or returns -ERANGE if the key depth is deeper than max depth.
290 * This is expected to be used with xbc_find_node() to list up all (child)
291 * keys under given key.
293 int __init
xbc_node_compose_key_after(struct xbc_node
*root
,
294 struct xbc_node
*node
,
295 char *buf
, size_t size
)
297 uint16_t keys
[XBC_DEPTH_MAX
];
298 int depth
= 0, ret
= 0, total
= 0;
300 if (!node
|| node
== root
)
303 if (xbc_node_is_value(node
))
304 node
= xbc_node_get_parent(node
);
306 while (node
&& node
!= root
) {
307 keys
[depth
++] = xbc_node_index(node
);
308 if (depth
== XBC_DEPTH_MAX
)
310 node
= xbc_node_get_parent(node
);
315 while (--depth
>= 0) {
316 node
= xbc_nodes
+ keys
[depth
];
317 ret
= snprintf(buf
, size
, "%s%s", xbc_node_get_data(node
),
334 * xbc_node_find_next_leaf() - Find the next leaf node under given node
335 * @root: An XBC root node
336 * @node: An XBC node which starts from.
338 * Search the next leaf node (which means the terminal key node) of @node
339 * under @root node (including @root node itself).
340 * Return the next node or NULL if next leaf node is not found.
342 struct xbc_node
* __init
xbc_node_find_next_leaf(struct xbc_node
*root
,
343 struct xbc_node
*node
)
345 struct xbc_node
*next
;
347 if (unlikely(!xbc_data
))
350 if (!node
) { /* First try */
355 /* Leaf node may have a subkey */
356 next
= xbc_node_get_subkey(node
);
362 if (node
== root
) /* @root was a leaf, no child node. */
365 while (!node
->next
) {
366 node
= xbc_node_get_parent(node
);
369 /* User passed a node which is not uder parent */
373 node
= xbc_node_get_next(node
);
377 while (node
&& !xbc_node_is_leaf(node
))
378 node
= xbc_node_get_child(node
);
384 * xbc_node_find_next_key_value() - Find the next key-value pair nodes
385 * @root: An XBC root node
386 * @leaf: A container pointer of XBC node which starts from.
388 * Search the next leaf node (which means the terminal key node) of *@leaf
389 * under @root node. Returns the value and update *@leaf if next leaf node
390 * is found, or NULL if no next leaf node is found.
391 * Note that this returns 0-length string if the key has no value, or
392 * the value of the first entry if the value is an array.
394 const char * __init
xbc_node_find_next_key_value(struct xbc_node
*root
,
395 struct xbc_node
**leaf
)
397 /* tip must be passed */
401 *leaf
= xbc_node_find_next_leaf(root
, *leaf
);
405 return xbc_node_get_data(xbc_node_get_child(*leaf
));
407 return ""; /* No value key */
410 /* XBC parse and tree build */
412 static int __init
xbc_init_node(struct xbc_node
*node
, char *data
, uint32_t flag
)
414 unsigned long offset
= data
- xbc_data
;
416 if (WARN_ON(offset
>= XBC_DATA_MAX
))
419 node
->data
= (uint16_t)offset
| flag
;
426 static struct xbc_node
* __init
xbc_add_node(char *data
, uint32_t flag
)
428 struct xbc_node
*node
;
430 if (xbc_node_num
== XBC_NODE_MAX
)
433 node
= &xbc_nodes
[xbc_node_num
++];
434 if (xbc_init_node(node
, data
, flag
) < 0)
440 static inline __init
struct xbc_node
*xbc_last_sibling(struct xbc_node
*node
)
443 node
= xbc_node_get_next(node
);
448 static inline __init
struct xbc_node
*xbc_last_child(struct xbc_node
*node
)
451 node
= xbc_node_get_child(node
);
456 static struct xbc_node
* __init
__xbc_add_sibling(char *data
, uint32_t flag
, bool head
)
458 struct xbc_node
*sib
, *node
= xbc_add_node(data
, flag
);
462 /* Ignore @head in this case */
463 node
->parent
= XBC_NODE_MAX
;
464 sib
= xbc_last_sibling(xbc_nodes
);
465 sib
->next
= xbc_node_index(node
);
467 node
->parent
= xbc_node_index(last_parent
);
468 if (!last_parent
->child
|| head
) {
469 node
->next
= last_parent
->child
;
470 last_parent
->child
= xbc_node_index(node
);
472 sib
= xbc_node_get_child(last_parent
);
473 sib
= xbc_last_sibling(sib
);
474 sib
->next
= xbc_node_index(node
);
478 xbc_parse_error("Too many nodes", data
);
483 static inline struct xbc_node
* __init
xbc_add_sibling(char *data
, uint32_t flag
)
485 return __xbc_add_sibling(data
, flag
, false);
488 static inline struct xbc_node
* __init
xbc_add_head_sibling(char *data
, uint32_t flag
)
490 return __xbc_add_sibling(data
, flag
, true);
493 static inline __init
struct xbc_node
*xbc_add_child(char *data
, uint32_t flag
)
495 struct xbc_node
*node
= xbc_add_sibling(data
, flag
);
503 static inline __init
bool xbc_valid_keyword(char *key
)
508 while (isalnum(*key
) || *key
== '-' || *key
== '_')
514 static char *skip_comment(char *p
)
518 ret
= strchr(p
, '\n');
527 static char *skip_spaces_until_newline(char *p
)
529 while (isspace(*p
) && *p
!= '\n')
534 static int __init
__xbc_open_brace(char *p
)
536 /* Push the last key as open brace */
537 open_brace
[brace_index
++] = xbc_node_index(last_parent
);
538 if (brace_index
>= XBC_DEPTH_MAX
)
539 return xbc_parse_error("Exceed max depth of braces", p
);
544 static int __init
__xbc_close_brace(char *p
)
547 if (!last_parent
|| brace_index
< 0 ||
548 (open_brace
[brace_index
] != xbc_node_index(last_parent
)))
549 return xbc_parse_error("Unexpected closing brace", p
);
551 if (brace_index
== 0)
554 last_parent
= &xbc_nodes
[open_brace
[brace_index
- 1]];
560 * Return delimiter or error, no node added. As same as lib/cmdline.c,
561 * you can use " around spaces, but can't escape " for value.
563 static int __init
__xbc_parse_value(char **__v
, char **__n
)
573 if (*v
== '"' || *v
== '\'') {
579 if (!isprint(c
) && !isspace(c
))
580 return xbc_parse_error("Non printable value", p
);
586 p
= skip_spaces_until_newline(p
);
588 if (c
&& !strchr(",;\n#}", c
))
589 return xbc_parse_error("No value delimiter", p
);
594 if (strchr(",;\n#}", c
)) {
601 return xbc_parse_error("No closing quotes", p
);
604 c
= '\n'; /* A comment must be treated as a newline */
612 static int __init
xbc_parse_array(char **__v
)
614 struct xbc_node
*node
;
618 if (last_parent
->child
)
619 last_parent
= xbc_node_get_child(last_parent
);
622 c
= __xbc_parse_value(__v
, &next
);
626 node
= xbc_add_child(*__v
, XBC_VALUE
);
637 struct xbc_node
*find_match_node(struct xbc_node
*node
, char *k
)
640 if (!strcmp(xbc_node_get_data(node
), k
))
642 node
= xbc_node_get_next(node
);
647 static int __init
__xbc_add_key(char *k
)
649 struct xbc_node
*node
, *child
;
651 if (!xbc_valid_keyword(k
))
652 return xbc_parse_error("Invalid keyword", k
);
654 if (unlikely(xbc_node_num
== 0))
657 if (!last_parent
) /* the first level */
658 node
= find_match_node(xbc_nodes
, k
);
660 child
= xbc_node_get_child(last_parent
);
661 /* Since the value node is the first child, skip it. */
662 if (child
&& xbc_node_is_value(child
))
663 child
= xbc_node_get_next(child
);
664 node
= find_match_node(child
, k
);
671 node
= xbc_add_child(k
, XBC_KEY
);
678 static int __init
__xbc_parse_keys(char *k
)
684 while ((p
= strchr(k
, '.'))) {
686 ret
= __xbc_add_key(k
);
692 return __xbc_add_key(k
);
695 static int __init
xbc_parse_kv(char **k
, char *v
, int op
)
697 struct xbc_node
*prev_parent
= last_parent
;
698 struct xbc_node
*child
;
702 ret
= __xbc_parse_keys(*k
);
706 c
= __xbc_parse_value(&v
, &next
);
710 child
= xbc_node_get_child(last_parent
);
711 if (child
&& xbc_node_is_value(child
)) {
713 return xbc_parse_error("Value is redefined", v
);
715 unsigned short nidx
= child
->next
;
717 xbc_init_node(child
, v
, XBC_VALUE
);
718 child
->next
= nidx
; /* keep subkeys */
722 last_parent
= xbc_last_child(child
);
724 /* The value node should always be the first child */
725 if (!xbc_add_head_sibling(v
, XBC_VALUE
))
729 if (c
== ',') { /* Array */
730 c
= xbc_parse_array(&next
);
735 last_parent
= prev_parent
;
738 ret
= __xbc_close_brace(next
- 1);
748 static int __init
xbc_parse_key(char **k
, char *n
)
750 struct xbc_node
*prev_parent
= last_parent
;
755 ret
= __xbc_parse_keys(*k
);
758 last_parent
= prev_parent
;
765 static int __init
xbc_open_brace(char **k
, char *n
)
769 ret
= __xbc_parse_keys(*k
);
774 return __xbc_open_brace(n
- 1);
777 static int __init
xbc_close_brace(char **k
, char *n
)
781 ret
= xbc_parse_key(k
, n
);
784 /* k is updated in xbc_parse_key() */
786 return __xbc_close_brace(n
- 1);
789 static int __init
xbc_verify_tree(void)
791 int i
, depth
, len
, wlen
;
792 struct xbc_node
*n
, *m
;
796 n
= &xbc_nodes
[open_brace
[brace_index
]];
797 return xbc_parse_error("Brace is not closed",
798 xbc_node_get_data(n
));
802 if (xbc_node_num
== 0) {
803 xbc_parse_error("Empty config", xbc_data
);
807 for (i
= 0; i
< xbc_node_num
; i
++) {
808 if (xbc_nodes
[i
].next
> xbc_node_num
) {
809 return xbc_parse_error("No closing brace",
810 xbc_node_get_data(xbc_nodes
+ i
));
814 /* Key tree limitation check */
820 wlen
= strlen(xbc_node_get_data(n
)) + 1;
822 if (len
> XBC_KEYLEN_MAX
)
823 return xbc_parse_error("Too long key length",
824 xbc_node_get_data(n
));
826 m
= xbc_node_get_child(n
);
827 if (m
&& xbc_node_is_key(m
)) {
830 if (depth
> XBC_DEPTH_MAX
)
831 return xbc_parse_error("Too many key words",
832 xbc_node_get_data(n
));
836 m
= xbc_node_get_next(n
);
838 n
= xbc_node_get_parent(n
);
841 len
-= strlen(xbc_node_get_data(n
)) + 1;
843 m
= xbc_node_get_next(n
);
851 /* Need to setup xbc_data and xbc_nodes before call this. */
852 static int __init
xbc_parse_tree(void)
860 q
= strpbrk(p
, "{}=+;:\n#");
864 ret
= xbc_parse_error("No delimiter", p
);
874 ret
= xbc_parse_error(c
== '+' ?
875 "Wrong '+' operator" :
876 "Wrong ':' operator",
882 ret
= xbc_parse_kv(&p
, q
, c
);
885 ret
= xbc_open_brace(&p
, q
);
892 ret
= xbc_parse_key(&p
, q
);
895 ret
= xbc_close_brace(&p
, q
);
904 * _xbc_exit() - Clean up all parsed bootconfig
905 * @early: Set true if this is called before budy system is initialized.
907 * This clears all data structures of parsed bootconfig on memory.
908 * If you need to reuse xbc_init() with new boot config, you can
911 void __init
_xbc_exit(bool early
)
913 xbc_free_mem(xbc_data
, xbc_data_size
, early
);
917 xbc_free_mem(xbc_nodes
, sizeof(struct xbc_node
) * XBC_NODE_MAX
, early
);
923 * xbc_init() - Parse given XBC file and build XBC internal tree
924 * @data: The boot config text original data
925 * @size: The size of @data
926 * @emsg: A pointer of const char * to store the error message
927 * @epos: A pointer of int to store the error position
929 * This parses the boot config text in @data. @size must be smaller
931 * Return the number of stored nodes (>0) if succeeded, or -errno
932 * if there is any error.
933 * In error cases, @emsg will be updated with an error message and
934 * @epos will be updated with the error position which is the byte offset
935 * of @buf. If the error is not a parser error, @epos will be -1.
937 int __init
xbc_init(const char *data
, size_t size
, const char **emsg
, int *epos
)
946 *emsg
= "Bootconfig is already initialized";
949 if (size
> XBC_DATA_MAX
|| size
== 0) {
951 *emsg
= size
? "Config data is too big" :
952 "Config data is empty";
956 xbc_data
= xbc_alloc_mem(size
+ 1);
959 *emsg
= "Failed to allocate bootconfig data";
962 memcpy(xbc_data
, data
, size
);
963 xbc_data
[size
] = '\0';
964 xbc_data_size
= size
+ 1;
966 xbc_nodes
= xbc_alloc_mem(sizeof(struct xbc_node
) * XBC_NODE_MAX
);
969 *emsg
= "Failed to allocate bootconfig nodes";
973 memset(xbc_nodes
, 0, sizeof(struct xbc_node
) * XBC_NODE_MAX
);
975 ret
= xbc_parse_tree();
977 ret
= xbc_verify_tree();