Merge pull request #1665 from antonio-nino-diaz-arm/an/fdt-helpers

Introduce new fdt helpers

common/fdt_wrappers.c

@@ -10,6 +10,7 @@
 #include <debug.h>
 #include <fdt_wrappers.h>
 #include <libfdt.h>
+#include <string.h>
 
 /*
  * Read cells from a given property of the given node. At most 2 cells of the
@@ -39,7 +40,6 @@ int fdtw_read_cells(const void *dtb, int node, const char *prop,
 		return -1;
 	}
 
-
 	/* Verify that property length accords with cell length */
 	if (NCELLS((unsigned int)value_len) != cells) {
 		WARN("Property length mismatch\n");
@@ -61,6 +61,77 @@ int fdtw_read_cells(const void *dtb, int node, const char *prop,
 	return 0;
 }
 
+/*
+ * Read cells from a given property of the given node. Any number of 32-bit
+ * cells of the property can be read. The fdt pointer is updated. Returns 0 on
+ * success, and -1 on error.
+ */
+int fdtw_read_array(const void *dtb, int node, const char *prop,
+		unsigned int cells, void *value)
+{
+	const uint32_t *value_ptr;
+	int value_len;
+
+	assert(dtb != NULL);
+	assert(prop != NULL);
+	assert(value != NULL);
+	assert(node >= 0);
+
+	/* Access property and obtain its length (in bytes) */
+	value_ptr = fdt_getprop_namelen(dtb, node, prop, (int)strlen(prop),
+			&value_len);
+	if (value_ptr == NULL) {
+		WARN("Couldn't find property %s in dtb\n", prop);
+		return -1;
+	}
+
+	/* Verify that property length accords with cell length */
+	if (NCELLS((unsigned int)value_len) != cells) {
+		WARN("Property length mismatch\n");
+		return -1;
+	}
+
+	uint32_t *dst = value;
+
+	for (unsigned int i = 0U; i < cells; i++) {
+		dst[i] = fdt32_to_cpu(value_ptr[i]);
+	}
+
+	return 0;
+}
+
+/*
+ * Read string from a given property of the given node. Up to 'size - 1'
+ * characters are read, and a NUL terminator is added. Returns 0 on success,
+ * and -1 upon error.
+ */
+int fdtw_read_string(const void *dtb, int node, const char *prop,
+		char *str, size_t size)
+{
+	const char *ptr;
+	size_t len;
+
+	assert(dtb != NULL);
+	assert(node >= 0);
+	assert(prop != NULL);
+	assert(str != NULL);
+	assert(size > 0U);
+
+	ptr = fdt_getprop_namelen(dtb, node, prop, (int)strlen(prop), NULL);
+	if (ptr == NULL) {
+		WARN("Couldn't find property %s in dtb\n", prop);
+		return -1;
+	}
+
+	len = strlcpy(str, ptr, size);
+	if (len >= size) {
+		WARN("String of property %s in dtb has been truncated\n", prop);
+		return -1;
+	}
+
+	return 0;
+}
+
 /*
  * Write cells in place to a given property of the given node. At most 2 cells
  * of the property are written. Returns 0 on success, and -1 upon error.

include/common/fdt_wrappers.h

@@ -14,6 +14,11 @@
 
 int fdtw_read_cells(const void *dtb, int node, const char *prop,
 		unsigned int cells, void *value);
+int fdtw_read_array(const void *dtb, int node, const char *prop,
+		unsigned int cells, void *value);
+int fdtw_read_string(const void *dtb, int node, const char *prop,
+		char *str, size_t size);
 int fdtw_write_inplace_cells(void *dtb, int node, const char *prop,
 		unsigned int cells, void *value);
+
 #endif /* __FDT_WRAPPERS__ */

include/lib/libc/string.h

@@ -28,5 +28,6 @@ void *memset(void *dst, int val, size_t count);
 size_t strlen(const char *s);
 size_t strnlen(const char *s, size_t maxlen);
 char *strrchr(const char *p, int ch);
+size_t strlcpy(char * dst, const char * src, size_t dsize);
 
 #endif /* STRING_H */

lib/libc/libc.mk

@@ -19,6 +19,7 @@ LIBC_SRCS	:=	$(addprefix lib/libc/,	\
 			snprintf.c			\
 			strchr.c			\
 			strcmp.c			\
+			strlcpy.c			\
 			strlen.c			\
 			strncmp.c			\
 			strnlen.c			\

lib/libc/strlcpy.c

@@ -0,0 +1,52 @@
+/*	$OpenBSD: strlcpy.c,v 1.12 2015/01/15 03:54:12 millert Exp $	*/
+
+/*
+ * SPDX-License-Identifier: ISC
+ *
+ * Copyright (c) 1998, 2015 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <stdint.h>
+#include <string.h>
+
+/*
+ * Copy string src to buffer dst of size dsize.  At most dsize-1
+ * chars will be copied.  Always NUL terminates (unless dsize == 0).
+ * Returns strlen(src); if retval >= dsize, truncation occurred.
+ */
+size_t
+strlcpy(char * dst, const char * src, size_t dsize)
+{
+	const char *osrc = src;
+	size_t nleft = dsize;
+
+	/* Copy as many bytes as will fit. */
+	if (nleft != 0) {
+		while (--nleft != 0) {
+			if ((*dst++ = *src++) == '\0')
+				break;
+		}
+	}
+
+	/* Not enough room in dst, add NUL and traverse rest of src. */
+	if (nleft == 0) {
+		if (dsize != 0)
+			*dst = '\0';		/* NUL-terminate dst */
+		while (*src++)
+			;
+	}
+
+	return(src - osrc - 1);	/* count does not include NUL */
+}