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1// SPDX-License-Identifier: GPL-2.02/*3 * Extra Boot Config4 * Masami Hiramatsu <mhiramat@kernel.org>5 */6 7/*8 * NOTE: This is only for tools/bootconfig, because tools/bootconfig will9 * run the parser sanity test.10 * This does NOT mean lib/bootconfig.c is available in the user space.11 * However, if you change this file, please make sure the tools/bootconfig12 * has no issue on building and running.13 */14#include <linux/bootconfig.h>15 16#ifdef __KERNEL__17#include <linux/bug.h>18#include <linux/ctype.h>19#include <linux/errno.h>20#include <linux/kernel.h>21#include <linux/memblock.h>22#include <linux/string.h>23 24#ifdef CONFIG_BOOT_CONFIG_EMBED25/* embedded_bootconfig_data is defined in bootconfig-data.S */26extern __visible const char embedded_bootconfig_data[];27extern __visible const char embedded_bootconfig_data_end[];28 29const char * __init xbc_get_embedded_bootconfig(size_t *size)30{31	*size = embedded_bootconfig_data_end - embedded_bootconfig_data;32	return (*size) ? embedded_bootconfig_data : NULL;33}34#endif35#endif36 37/*38 * Extra Boot Config (XBC) is given as tree-structured ascii text of39 * key-value pairs on memory.40 * xbc_parse() parses the text to build a simple tree. Each tree node is41 * simply a key word or a value. A key node may have a next key node or/and42 * a child node (both key and value). A value node may have a next value43 * node (for array).44 */45 46static struct xbc_node *xbc_nodes __initdata;47static int xbc_node_num __initdata;48static char *xbc_data __initdata;49static size_t xbc_data_size __initdata;50static struct xbc_node *last_parent __initdata;51static const char *xbc_err_msg __initdata;52static int xbc_err_pos __initdata;53static int open_brace[XBC_DEPTH_MAX] __initdata;54static int brace_index __initdata;55 56#ifdef __KERNEL__57static inline void * __init xbc_alloc_mem(size_t size)58{59	return memblock_alloc(size, SMP_CACHE_BYTES);60}61 62static inline void __init xbc_free_mem(void *addr, size_t size, bool early)63{64	if (early)65		memblock_free(addr, size);66	else if (addr)67		memblock_free_late(__pa(addr), size);68}69 70#else /* !__KERNEL__ */71 72static inline void *xbc_alloc_mem(size_t size)73{74	return malloc(size);75}76 77static inline void xbc_free_mem(void *addr, size_t size, bool early)78{79	free(addr);80}81#endif82/**83 * xbc_get_info() - Get the information of loaded boot config84 * @node_size: A pointer to store the number of nodes.85 * @data_size: A pointer to store the size of bootconfig data.86 *87 * Get the number of used nodes in @node_size if it is not NULL,88 * and the size of bootconfig data in @data_size if it is not NULL.89 * Return 0 if the boot config is initialized, or return -ENODEV.90 */91int __init xbc_get_info(int *node_size, size_t *data_size)92{93	if (!xbc_data)94		return -ENODEV;95 96	if (node_size)97		*node_size = xbc_node_num;98	if (data_size)99		*data_size = xbc_data_size;100	return 0;101}102 103static int __init xbc_parse_error(const char *msg, const char *p)104{105	xbc_err_msg = msg;106	xbc_err_pos = (int)(p - xbc_data);107 108	return -EINVAL;109}110 111/**112 * xbc_root_node() - Get the root node of extended boot config113 *114 * Return the address of root node of extended boot config. If the115 * extended boot config is not initiized, return NULL.116 */117struct xbc_node * __init xbc_root_node(void)118{119	if (unlikely(!xbc_data))120		return NULL;121 122	return xbc_nodes;123}124 125/**126 * xbc_node_index() - Get the index of XBC node127 * @node: A target node of getting index.128 *129 * Return the index number of @node in XBC node list.130 */131int __init xbc_node_index(struct xbc_node *node)132{133	return node - &xbc_nodes[0];134}135 136/**137 * xbc_node_get_parent() - Get the parent XBC node138 * @node: An XBC node.139 *140 * Return the parent node of @node. If the node is top node of the tree,141 * return NULL.142 */143struct xbc_node * __init xbc_node_get_parent(struct xbc_node *node)144{145	return node->parent == XBC_NODE_MAX ? NULL : &xbc_nodes[node->parent];146}147 148/**149 * xbc_node_get_child() - Get the child XBC node150 * @node: An XBC node.151 *152 * Return the first child node of @node. If the node has no child, return153 * NULL.154 */155struct xbc_node * __init xbc_node_get_child(struct xbc_node *node)156{157	return node->child ? &xbc_nodes[node->child] : NULL;158}159 160/**161 * xbc_node_get_next() - Get the next sibling XBC node162 * @node: An XBC node.163 *164 * Return the NEXT sibling node of @node. If the node has no next sibling,165 * return NULL. Note that even if this returns NULL, it doesn't mean @node166 * has no siblings. (You also has to check whether the parent's child node167 * is @node or not.)168 */169struct xbc_node * __init xbc_node_get_next(struct xbc_node *node)170{171	return node->next ? &xbc_nodes[node->next] : NULL;172}173 174/**175 * xbc_node_get_data() - Get the data of XBC node176 * @node: An XBC node.177 *178 * Return the data (which is always a null terminated string) of @node.179 * If the node has invalid data, warn and return NULL.180 */181const char * __init xbc_node_get_data(struct xbc_node *node)182{183	int offset = node->data & ~XBC_VALUE;184 185	if (WARN_ON(offset >= xbc_data_size))186		return NULL;187 188	return xbc_data + offset;189}190 191static bool __init192xbc_node_match_prefix(struct xbc_node *node, const char **prefix)193{194	const char *p = xbc_node_get_data(node);195	int len = strlen(p);196 197	if (strncmp(*prefix, p, len))198		return false;199 200	p = *prefix + len;201	if (*p == '.')202		p++;203	else if (*p != '\0')204		return false;205	*prefix = p;206 207	return true;208}209 210/**211 * xbc_node_find_subkey() - Find a subkey node which matches given key212 * @parent: An XBC node.213 * @key: A key string.214 *215 * Search a key node under @parent which matches @key. The @key can contain216 * several words jointed with '.'. If @parent is NULL, this searches the217 * node from whole tree. Return NULL if no node is matched.218 */219struct xbc_node * __init220xbc_node_find_subkey(struct xbc_node *parent, const char *key)221{222	struct xbc_node *node;223 224	if (parent)225		node = xbc_node_get_subkey(parent);226	else227		node = xbc_root_node();228 229	while (node && xbc_node_is_key(node)) {230		if (!xbc_node_match_prefix(node, &key))231			node = xbc_node_get_next(node);232		else if (*key != '\0')233			node = xbc_node_get_subkey(node);234		else235			break;236	}237 238	return node;239}240 241/**242 * xbc_node_find_value() - Find a value node which matches given key243 * @parent: An XBC node.244 * @key: A key string.245 * @vnode: A container pointer of found XBC node.246 *247 * Search a value node under @parent whose (parent) key node matches @key,248 * store it in *@vnode, and returns the value string.249 * The @key can contain several words jointed with '.'. If @parent is NULL,250 * this searches the node from whole tree. Return the value string if a251 * matched key found, return NULL if no node is matched.252 * Note that this returns 0-length string and stores NULL in *@vnode if the253 * key has no value. And also it will return the value of the first entry if254 * the value is an array.255 */256const char * __init257xbc_node_find_value(struct xbc_node *parent, const char *key,258		    struct xbc_node **vnode)259{260	struct xbc_node *node = xbc_node_find_subkey(parent, key);261 262	if (!node || !xbc_node_is_key(node))263		return NULL;264 265	node = xbc_node_get_child(node);266	if (node && !xbc_node_is_value(node))267		return NULL;268 269	if (vnode)270		*vnode = node;271 272	return node ? xbc_node_get_data(node) : "";273}274 275/**276 * xbc_node_compose_key_after() - Compose partial key string of the XBC node277 * @root: Root XBC node278 * @node: Target XBC node.279 * @buf: A buffer to store the key.280 * @size: The size of the @buf.281 *282 * Compose the partial key of the @node into @buf, which is starting right283 * after @root (@root is not included.) If @root is NULL, this returns full284 * key words of @node.285 * Returns the total length of the key stored in @buf. Returns -EINVAL286 * if @node is NULL or @root is not the ancestor of @node or @root is @node,287 * or returns -ERANGE if the key depth is deeper than max depth.288 * This is expected to be used with xbc_find_node() to list up all (child)289 * keys under given key.290 */291int __init xbc_node_compose_key_after(struct xbc_node *root,292				      struct xbc_node *node,293				      char *buf, size_t size)294{295	uint16_t keys[XBC_DEPTH_MAX];296	int depth = 0, ret = 0, total = 0;297 298	if (!node || node == root)299		return -EINVAL;300 301	if (xbc_node_is_value(node))302		node = xbc_node_get_parent(node);303 304	while (node && node != root) {305		keys[depth++] = xbc_node_index(node);306		if (depth == XBC_DEPTH_MAX)307			return -ERANGE;308		node = xbc_node_get_parent(node);309	}310	if (!node && root)311		return -EINVAL;312 313	while (--depth >= 0) {314		node = xbc_nodes + keys[depth];315		ret = snprintf(buf, size, "%s%s", xbc_node_get_data(node),316			       depth ? "." : "");317		if (ret < 0)318			return ret;319		if (ret > size) {320			size = 0;321		} else {322			size -= ret;323			buf += ret;324		}325		total += ret;326	}327 328	return total;329}330 331/**332 * xbc_node_find_next_leaf() - Find the next leaf node under given node333 * @root: An XBC root node334 * @node: An XBC node which starts from.335 *336 * Search the next leaf node (which means the terminal key node) of @node337 * under @root node (including @root node itself).338 * Return the next node or NULL if next leaf node is not found.339 */340struct xbc_node * __init xbc_node_find_next_leaf(struct xbc_node *root,341						 struct xbc_node *node)342{343	struct xbc_node *next;344 345	if (unlikely(!xbc_data))346		return NULL;347 348	if (!node) {	/* First try */349		node = root;350		if (!node)351			node = xbc_nodes;352	} else {353		/* Leaf node may have a subkey */354		next = xbc_node_get_subkey(node);355		if (next) {356			node = next;357			goto found;358		}359 360		if (node == root)	/* @root was a leaf, no child node. */361			return NULL;362 363		while (!node->next) {364			node = xbc_node_get_parent(node);365			if (node == root)366				return NULL;367			/* User passed a node which is not uder parent */368			if (WARN_ON(!node))369				return NULL;370		}371		node = xbc_node_get_next(node);372	}373 374found:375	while (node && !xbc_node_is_leaf(node))376		node = xbc_node_get_child(node);377 378	return node;379}380 381/**382 * xbc_node_find_next_key_value() - Find the next key-value pair nodes383 * @root: An XBC root node384 * @leaf: A container pointer of XBC node which starts from.385 *386 * Search the next leaf node (which means the terminal key node) of *@leaf387 * under @root node. Returns the value and update *@leaf if next leaf node388 * is found, or NULL if no next leaf node is found.389 * Note that this returns 0-length string if the key has no value, or390 * the value of the first entry if the value is an array.391 */392const char * __init xbc_node_find_next_key_value(struct xbc_node *root,393						 struct xbc_node **leaf)394{395	/* tip must be passed */396	if (WARN_ON(!leaf))397		return NULL;398 399	*leaf = xbc_node_find_next_leaf(root, *leaf);400	if (!*leaf)401		return NULL;402	if ((*leaf)->child)403		return xbc_node_get_data(xbc_node_get_child(*leaf));404	else405		return "";	/* No value key */406}407 408/* XBC parse and tree build */409 410static int __init xbc_init_node(struct xbc_node *node, char *data, uint32_t flag)411{412	unsigned long offset = data - xbc_data;413 414	if (WARN_ON(offset >= XBC_DATA_MAX))415		return -EINVAL;416 417	node->data = (uint16_t)offset | flag;418	node->child = 0;419	node->next = 0;420 421	return 0;422}423 424static struct xbc_node * __init xbc_add_node(char *data, uint32_t flag)425{426	struct xbc_node *node;427 428	if (xbc_node_num == XBC_NODE_MAX)429		return NULL;430 431	node = &xbc_nodes[xbc_node_num++];432	if (xbc_init_node(node, data, flag) < 0)433		return NULL;434 435	return node;436}437 438static inline __init struct xbc_node *xbc_last_sibling(struct xbc_node *node)439{440	while (node->next)441		node = xbc_node_get_next(node);442 443	return node;444}445 446static inline __init struct xbc_node *xbc_last_child(struct xbc_node *node)447{448	while (node->child)449		node = xbc_node_get_child(node);450 451	return node;452}453 454static struct xbc_node * __init __xbc_add_sibling(char *data, uint32_t flag, bool head)455{456	struct xbc_node *sib, *node = xbc_add_node(data, flag);457 458	if (node) {459		if (!last_parent) {460			/* Ignore @head in this case */461			node->parent = XBC_NODE_MAX;462			sib = xbc_last_sibling(xbc_nodes);463			sib->next = xbc_node_index(node);464		} else {465			node->parent = xbc_node_index(last_parent);466			if (!last_parent->child || head) {467				node->next = last_parent->child;468				last_parent->child = xbc_node_index(node);469			} else {470				sib = xbc_node_get_child(last_parent);471				sib = xbc_last_sibling(sib);472				sib->next = xbc_node_index(node);473			}474		}475	} else476		xbc_parse_error("Too many nodes", data);477 478	return node;479}480 481static inline struct xbc_node * __init xbc_add_sibling(char *data, uint32_t flag)482{483	return __xbc_add_sibling(data, flag, false);484}485 486static inline struct xbc_node * __init xbc_add_head_sibling(char *data, uint32_t flag)487{488	return __xbc_add_sibling(data, flag, true);489}490 491static inline __init struct xbc_node *xbc_add_child(char *data, uint32_t flag)492{493	struct xbc_node *node = xbc_add_sibling(data, flag);494 495	if (node)496		last_parent = node;497 498	return node;499}500 501static inline __init bool xbc_valid_keyword(char *key)502{503	if (key[0] == '\0')504		return false;505 506	while (isalnum(*key) || *key == '-' || *key == '_')507		key++;508 509	return *key == '\0';510}511 512static char *skip_comment(char *p)513{514	char *ret;515 516	ret = strchr(p, '\n');517	if (!ret)518		ret = p + strlen(p);519	else520		ret++;521 522	return ret;523}524 525static char *skip_spaces_until_newline(char *p)526{527	while (isspace(*p) && *p != '\n')528		p++;529	return p;530}531 532static int __init __xbc_open_brace(char *p)533{534	/* Push the last key as open brace */535	open_brace[brace_index++] = xbc_node_index(last_parent);536	if (brace_index >= XBC_DEPTH_MAX)537		return xbc_parse_error("Exceed max depth of braces", p);538 539	return 0;540}541 542static int __init __xbc_close_brace(char *p)543{544	brace_index--;545	if (!last_parent || brace_index < 0 ||546	    (open_brace[brace_index] != xbc_node_index(last_parent)))547		return xbc_parse_error("Unexpected closing brace", p);548 549	if (brace_index == 0)550		last_parent = NULL;551	else552		last_parent = &xbc_nodes[open_brace[brace_index - 1]];553 554	return 0;555}556 557/*558 * Return delimiter or error, no node added. As same as lib/cmdline.c,559 * you can use " around spaces, but can't escape " for value.560 */561static int __init __xbc_parse_value(char **__v, char **__n)562{563	char *p, *v = *__v;564	int c, quotes = 0;565 566	v = skip_spaces(v);567	while (*v == '#') {568		v = skip_comment(v);569		v = skip_spaces(v);570	}571	if (*v == '"' || *v == '\'') {572		quotes = *v;573		v++;574	}575	p = v - 1;576	while ((c = *++p)) {577		if (!isprint(c) && !isspace(c))578			return xbc_parse_error("Non printable value", p);579		if (quotes) {580			if (c != quotes)581				continue;582			quotes = 0;583			*p++ = '\0';584			p = skip_spaces_until_newline(p);585			c = *p;586			if (c && !strchr(",;\n#}", c))587				return xbc_parse_error("No value delimiter", p);588			if (*p)589				p++;590			break;591		}592		if (strchr(",;\n#}", c)) {593			*p++ = '\0';594			v = strim(v);595			break;596		}597	}598	if (quotes)599		return xbc_parse_error("No closing quotes", p);600	if (c == '#') {601		p = skip_comment(p);602		c = '\n';	/* A comment must be treated as a newline */603	}604	*__n = p;605	*__v = v;606 607	return c;608}609 610static int __init xbc_parse_array(char **__v)611{612	struct xbc_node *node;613	char *next;614	int c = 0;615 616	if (last_parent->child)617		last_parent = xbc_node_get_child(last_parent);618 619	do {620		c = __xbc_parse_value(__v, &next);621		if (c < 0)622			return c;623 624		node = xbc_add_child(*__v, XBC_VALUE);625		if (!node)626			return -ENOMEM;627		*__v = next;628	} while (c == ',');629	node->child = 0;630 631	return c;632}633 634static inline __init635struct xbc_node *find_match_node(struct xbc_node *node, char *k)636{637	while (node) {638		if (!strcmp(xbc_node_get_data(node), k))639			break;640		node = xbc_node_get_next(node);641	}642	return node;643}644 645static int __init __xbc_add_key(char *k)646{647	struct xbc_node *node, *child;648 649	if (!xbc_valid_keyword(k))650		return xbc_parse_error("Invalid keyword", k);651 652	if (unlikely(xbc_node_num == 0))653		goto add_node;654 655	if (!last_parent)	/* the first level */656		node = find_match_node(xbc_nodes, k);657	else {658		child = xbc_node_get_child(last_parent);659		/* Since the value node is the first child, skip it. */660		if (child && xbc_node_is_value(child))661			child = xbc_node_get_next(child);662		node = find_match_node(child, k);663	}664 665	if (node)666		last_parent = node;667	else {668add_node:669		node = xbc_add_child(k, XBC_KEY);670		if (!node)671			return -ENOMEM;672	}673	return 0;674}675 676static int __init __xbc_parse_keys(char *k)677{678	char *p;679	int ret;680 681	k = strim(k);682	while ((p = strchr(k, '.'))) {683		*p++ = '\0';684		ret = __xbc_add_key(k);685		if (ret)686			return ret;687		k = p;688	}689 690	return __xbc_add_key(k);691}692 693static int __init xbc_parse_kv(char **k, char *v, int op)694{695	struct xbc_node *prev_parent = last_parent;696	struct xbc_node *child;697	char *next;698	int c, ret;699 700	ret = __xbc_parse_keys(*k);701	if (ret)702		return ret;703 704	c = __xbc_parse_value(&v, &next);705	if (c < 0)706		return c;707 708	child = xbc_node_get_child(last_parent);709	if (child && xbc_node_is_value(child)) {710		if (op == '=')711			return xbc_parse_error("Value is redefined", v);712		if (op == ':') {713			unsigned short nidx = child->next;714 715			xbc_init_node(child, v, XBC_VALUE);716			child->next = nidx;	/* keep subkeys */717			goto array;718		}719		/* op must be '+' */720		last_parent = xbc_last_child(child);721	}722	/* The value node should always be the first child */723	if (!xbc_add_head_sibling(v, XBC_VALUE))724		return -ENOMEM;725 726array:727	if (c == ',') {	/* Array */728		c = xbc_parse_array(&next);729		if (c < 0)730			return c;731	}732 733	last_parent = prev_parent;734 735	if (c == '}') {736		ret = __xbc_close_brace(next - 1);737		if (ret < 0)738			return ret;739	}740 741	*k = next;742 743	return 0;744}745 746static int __init xbc_parse_key(char **k, char *n)747{748	struct xbc_node *prev_parent = last_parent;749	int ret;750 751	*k = strim(*k);752	if (**k != '\0') {753		ret = __xbc_parse_keys(*k);754		if (ret)755			return ret;756		last_parent = prev_parent;757	}758	*k = n;759 760	return 0;761}762 763static int __init xbc_open_brace(char **k, char *n)764{765	int ret;766 767	ret = __xbc_parse_keys(*k);768	if (ret)769		return ret;770	*k = n;771 772	return __xbc_open_brace(n - 1);773}774 775static int __init xbc_close_brace(char **k, char *n)776{777	int ret;778 779	ret = xbc_parse_key(k, n);780	if (ret)781		return ret;782	/* k is updated in xbc_parse_key() */783 784	return __xbc_close_brace(n - 1);785}786 787static int __init xbc_verify_tree(void)788{789	int i, depth, len, wlen;790	struct xbc_node *n, *m;791 792	/* Brace closing */793	if (brace_index) {794		n = &xbc_nodes[open_brace[brace_index]];795		return xbc_parse_error("Brace is not closed",796					xbc_node_get_data(n));797	}798 799	/* Empty tree */800	if (xbc_node_num == 0) {801		xbc_parse_error("Empty config", xbc_data);802		return -ENOENT;803	}804 805	for (i = 0; i < xbc_node_num; i++) {806		if (xbc_nodes[i].next > xbc_node_num) {807			return xbc_parse_error("No closing brace",808				xbc_node_get_data(xbc_nodes + i));809		}810	}811 812	/* Key tree limitation check */813	n = &xbc_nodes[0];814	depth = 1;815	len = 0;816 817	while (n) {818		wlen = strlen(xbc_node_get_data(n)) + 1;819		len += wlen;820		if (len > XBC_KEYLEN_MAX)821			return xbc_parse_error("Too long key length",822				xbc_node_get_data(n));823 824		m = xbc_node_get_child(n);825		if (m && xbc_node_is_key(m)) {826			n = m;827			depth++;828			if (depth > XBC_DEPTH_MAX)829				return xbc_parse_error("Too many key words",830						xbc_node_get_data(n));831			continue;832		}833		len -= wlen;834		m = xbc_node_get_next(n);835		while (!m) {836			n = xbc_node_get_parent(n);837			if (!n)838				break;839			len -= strlen(xbc_node_get_data(n)) + 1;840			depth--;841			m = xbc_node_get_next(n);842		}843		n = m;844	}845 846	return 0;847}848 849/* Need to setup xbc_data and xbc_nodes before call this. */850static int __init xbc_parse_tree(void)851{852	char *p, *q;853	int ret = 0, c;854 855	last_parent = NULL;856	p = xbc_data;857	do {858		q = strpbrk(p, "{}=+;:\n#");859		if (!q) {860			p = skip_spaces(p);861			if (*p != '\0')862				ret = xbc_parse_error("No delimiter", p);863			break;864		}865 866		c = *q;867		*q++ = '\0';868		switch (c) {869		case ':':870		case '+':871			if (*q++ != '=') {872				ret = xbc_parse_error(c == '+' ?873						"Wrong '+' operator" :874						"Wrong ':' operator",875							q - 2);876				break;877			}878			fallthrough;879		case '=':880			ret = xbc_parse_kv(&p, q, c);881			break;882		case '{':883			ret = xbc_open_brace(&p, q);884			break;885		case '#':886			q = skip_comment(q);887			fallthrough;888		case ';':889		case '\n':890			ret = xbc_parse_key(&p, q);891			break;892		case '}':893			ret = xbc_close_brace(&p, q);894			break;895		}896	} while (!ret);897 898	return ret;899}900 901/**902 * _xbc_exit() - Clean up all parsed bootconfig903 * @early: Set true if this is called before budy system is initialized.904 *905 * This clears all data structures of parsed bootconfig on memory.906 * If you need to reuse xbc_init() with new boot config, you can907 * use this.908 */909void __init _xbc_exit(bool early)910{911	xbc_free_mem(xbc_data, xbc_data_size, early);912	xbc_data = NULL;913	xbc_data_size = 0;914	xbc_node_num = 0;915	xbc_free_mem(xbc_nodes, sizeof(struct xbc_node) * XBC_NODE_MAX, early);916	xbc_nodes = NULL;917	brace_index = 0;918}919 920/**921 * xbc_init() - Parse given XBC file and build XBC internal tree922 * @data: The boot config text original data923 * @size: The size of @data924 * @emsg: A pointer of const char * to store the error message925 * @epos: A pointer of int to store the error position926 *927 * This parses the boot config text in @data. @size must be smaller928 * than XBC_DATA_MAX.929 * Return the number of stored nodes (>0) if succeeded, or -errno930 * if there is any error.931 * In error cases, @emsg will be updated with an error message and932 * @epos will be updated with the error position which is the byte offset933 * of @buf. If the error is not a parser error, @epos will be -1.934 */935int __init xbc_init(const char *data, size_t size, const char **emsg, int *epos)936{937	int ret;938 939	if (epos)940		*epos = -1;941 942	if (xbc_data) {943		if (emsg)944			*emsg = "Bootconfig is already initialized";945		return -EBUSY;946	}947	if (size > XBC_DATA_MAX || size == 0) {948		if (emsg)949			*emsg = size ? "Config data is too big" :950				"Config data is empty";951		return -ERANGE;952	}953 954	xbc_data = xbc_alloc_mem(size + 1);955	if (!xbc_data) {956		if (emsg)957			*emsg = "Failed to allocate bootconfig data";958		return -ENOMEM;959	}960	memcpy(xbc_data, data, size);961	xbc_data[size] = '\0';962	xbc_data_size = size + 1;963 964	xbc_nodes = xbc_alloc_mem(sizeof(struct xbc_node) * XBC_NODE_MAX);965	if (!xbc_nodes) {966		if (emsg)967			*emsg = "Failed to allocate bootconfig nodes";968		_xbc_exit(true);969		return -ENOMEM;970	}971	memset(xbc_nodes, 0, sizeof(struct xbc_node) * XBC_NODE_MAX);972 973	ret = xbc_parse_tree();974	if (!ret)975		ret = xbc_verify_tree();976 977	if (ret < 0) {978		if (epos)979			*epos = xbc_err_pos;980		if (emsg)981			*emsg = xbc_err_msg;982		_xbc_exit(true);983	} else984		ret = xbc_node_num;985 986	return ret;987}988