summaryrefslogtreecommitdiff
path: root/libfdt/fdt_ro.c
diff options
context:
space:
mode:
Diffstat (limited to 'libfdt/fdt_ro.c')
-rw-r--r--libfdt/fdt_ro.c402
1 files changed, 402 insertions, 0 deletions
diff --git a/libfdt/fdt_ro.c b/libfdt/fdt_ro.c
new file mode 100644
index 0000000..4e2c325
--- /dev/null
+++ b/libfdt/fdt_ro.c
@@ -0,0 +1,402 @@
+/*
+ * libfdt - Flat Device Tree manipulation
+ * Copyright (C) 2006 David Gibson, IBM Corporation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+#include "libfdt_env.h"
+
+#include <fdt.h>
+#include <libfdt.h>
+
+#include "libfdt_internal.h"
+
+#define CHECK_HEADER(fdt) { \
+ int err; \
+ if ((err = fdt_check_header(fdt)) != 0) \
+ return err; \
+}
+
+static int offset_streq(const void *fdt, int offset,
+ const char *s, int len)
+{
+ const char *p = fdt_offset_ptr(fdt, offset, len+1);
+
+ if (! p)
+ /* short match */
+ return 0;
+
+ if (memcmp(p, s, len) != 0)
+ return 0;
+
+ if (p[len] != '\0')
+ return 0;
+
+ return 1;
+}
+
+/*
+ * Return a pointer to the string at the given string offset.
+ */
+char *fdt_string(const void *fdt, int stroffset)
+{
+ return (char *)fdt + fdt_off_dt_strings(fdt) + stroffset;
+}
+
+/*
+ * Return the node offset of the node specified by:
+ * parentoffset - starting place (0 to start at the root)
+ * name - name being searched for
+ * namelen - length of the name: typically strlen(name)
+ *
+ * Notes:
+ * If the start node has subnodes, the subnodes are _not_ searched for the
+ * requested name.
+ */
+int fdt_subnode_offset_namelen(const void *fdt, int parentoffset,
+ const char *name, int namelen)
+{
+ int level = 0;
+ uint32_t tag;
+ int offset, nextoffset;
+
+ CHECK_HEADER(fdt);
+
+ tag = fdt_next_tag(fdt, parentoffset, &nextoffset, NULL);
+ if (tag != FDT_BEGIN_NODE)
+ return -FDT_ERR_BADOFFSET;
+
+ do {
+ offset = nextoffset;
+ tag = fdt_next_tag(fdt, offset, &nextoffset, NULL);
+
+ switch (tag) {
+ case FDT_END:
+ return -FDT_ERR_TRUNCATED;
+
+ case FDT_BEGIN_NODE:
+ level++;
+ /*
+ * If we are nested down levels, ignore the strings
+ * until we get back to the proper level.
+ */
+ if (level != 1)
+ continue;
+
+ /* Return the offset if this is "our" string. */
+ if (offset_streq(fdt, offset+FDT_TAGSIZE, name, namelen))
+ return offset;
+ break;
+
+ case FDT_END_NODE:
+ level--;
+ break;
+
+ case FDT_PROP:
+ case FDT_NOP:
+ break;
+
+ default:
+ return -FDT_ERR_BADSTRUCTURE;
+ }
+ } while (level >= 0);
+
+ return -FDT_ERR_NOTFOUND;
+}
+
+/*
+ * See fdt_subnode_offset_namelen()
+ */
+int fdt_subnode_offset(const void *fdt, int parentoffset,
+ const char *name)
+{
+ return fdt_subnode_offset_namelen(fdt, parentoffset, name, strlen(name));
+}
+
+/*
+ * Searches for the node corresponding to the given path and returns the
+ * offset of that node.
+ */
+int fdt_path_offset(const void *fdt, const char *path)
+{
+ const char *end = path + strlen(path);
+ const char *p = path;
+ int offset = 0;
+
+ CHECK_HEADER(fdt);
+
+ /* Paths must be absolute */
+ if (*path != '/')
+ return -FDT_ERR_BADPATH;
+
+ while (*p) {
+ const char *q;
+
+ /* Skip path separator(s) */
+ while (*p == '/')
+ p++;
+ if (! *p)
+ return -FDT_ERR_BADPATH;
+
+ /*
+ * Find the next path separator. The characters between
+ * p and q are the next segment of the the path to find.
+ */
+ q = strchr(p, '/');
+ if (! q)
+ q = end;
+
+ /*
+ * Find the offset corresponding to the this path segment.
+ */
+ offset = fdt_subnode_offset_namelen(fdt, offset, p, q-p);
+
+ /* Oops, error, abort abort abort */
+ if (offset < 0)
+ return offset;
+
+ p = q;
+ }
+
+ return offset;
+}
+
+/*
+ * Given the offset of a node and a name of a property in that node, return
+ * a pointer to the property struct.
+ */
+struct fdt_property *fdt_get_property(const void *fdt,
+ int nodeoffset,
+ const char *name, int *lenp)
+{
+ int level = 0;
+ uint32_t tag;
+ struct fdt_property *prop;
+ int namestroff;
+ int offset, nextoffset;
+ int err;
+
+ if ((err = fdt_check_header(fdt)) != 0)
+ goto fail;
+
+ err = -FDT_ERR_BADOFFSET;
+ if (nodeoffset % FDT_TAGSIZE)
+ goto fail;
+
+ tag = fdt_next_tag(fdt, nodeoffset, &nextoffset, NULL);
+ if (tag != FDT_BEGIN_NODE)
+ goto fail;
+
+ do {
+ offset = nextoffset;
+
+ tag = fdt_next_tag(fdt, offset, &nextoffset, NULL);
+ switch (tag) {
+ case FDT_END:
+ err = -FDT_ERR_TRUNCATED;
+ goto fail;
+
+ case FDT_BEGIN_NODE:
+ level++;
+ break;
+
+ case FDT_END_NODE:
+ level--;
+ break;
+
+ case FDT_PROP:
+ /*
+ * If we are nested down levels, ignore the strings
+ * until we get back to the proper level.
+ */
+ if (level != 0)
+ continue;
+
+ err = -FDT_ERR_BADSTRUCTURE;
+ prop = fdt_offset_ptr_typed(fdt, offset, prop);
+ if (! prop)
+ goto fail;
+ namestroff = fdt32_to_cpu(prop->nameoff);
+ if (streq(fdt_string(fdt, namestroff), name)) {
+ /* Found it! */
+ int len = fdt32_to_cpu(prop->len);
+ prop = fdt_offset_ptr(fdt, offset,
+ sizeof(*prop)+len);
+ if (! prop)
+ goto fail;
+
+ if (lenp)
+ *lenp = len;
+
+ return prop;
+ }
+ break;
+
+ case FDT_NOP:
+ break;
+
+ default:
+ err = -FDT_ERR_BADSTRUCTURE;
+ goto fail;
+ }
+ } while (level >= 0);
+
+ err = -FDT_ERR_NOTFOUND;
+fail:
+ if (lenp)
+ *lenp = err;
+ return NULL;
+}
+
+/*
+ * Given the offset of a node and a name of a property in that node, return
+ * a pointer to the property data (ONLY).
+ */
+void *fdt_getprop(const void *fdt, int nodeoffset,
+ const char *name, int *lenp)
+{
+ const struct fdt_property *prop;
+
+ prop = fdt_get_property(fdt, nodeoffset, name, lenp);
+ if (! prop)
+ return NULL;
+
+ return (void *)prop->data;
+}
+
+
+uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset, char **namep)
+{
+ const uint32_t *tagp, *lenp;
+ uint32_t tag;
+ const char *p;
+
+ if (offset % FDT_TAGSIZE)
+ return -1;
+
+ tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE);
+ if (! tagp)
+ return FDT_END; /* premature end */
+ tag = fdt32_to_cpu(*tagp);
+ offset += FDT_TAGSIZE;
+
+ switch (tag) {
+ case FDT_BEGIN_NODE:
+ if(namep)
+ *namep = fdt_offset_ptr(fdt, offset, 1);
+
+ /* skip name */
+ do {
+ p = fdt_offset_ptr(fdt, offset++, 1);
+ } while (p && (*p != '\0'));
+ if (! p)
+ return FDT_END;
+ break;
+ case FDT_PROP:
+ lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp));
+ if (! lenp)
+ return FDT_END;
+ /*
+ * Get the property and set the namep to the name.
+ */
+ if(namep) {
+ struct fdt_property *prop;
+
+ prop = fdt_offset_ptr_typed(fdt, offset - FDT_TAGSIZE, prop);
+ if (! prop)
+ return -FDT_ERR_BADSTRUCTURE;
+ *namep = fdt_string(fdt, fdt32_to_cpu(prop->nameoff));
+ }
+ /* skip name offset, length and value */
+ offset += 2*FDT_TAGSIZE + fdt32_to_cpu(*lenp);
+ break;
+ }
+
+ if (nextoffset)
+ *nextoffset = ALIGN(offset, FDT_TAGSIZE);
+
+ return tag;
+}
+
+/*
+ * Return the number of used reserve map entries and total slots available.
+ */
+int fdt_num_reservemap(void *fdt, int *used, int *total)
+{
+ struct fdt_reserve_entry *re;
+ int start;
+ int end;
+ int err = fdt_check_header(fdt);
+
+ if (err != 0)
+ return err;
+
+ start = fdt_off_mem_rsvmap(fdt);
+
+ /*
+ * Convention is that the reserve map is before the dt_struct,
+ * but it does not have to be.
+ */
+ end = fdt_totalsize(fdt);
+ if (end > fdt_off_dt_struct(fdt))
+ end = fdt_off_dt_struct(fdt);
+ if (end > fdt_off_dt_strings(fdt))
+ end = fdt_off_dt_strings(fdt);
+
+ /*
+ * Since the reserved area list is zero terminated, you get one fewer.
+ */
+ if (total)
+ *total = ((end - start) / sizeof(struct fdt_reserve_entry)) - 1;
+
+ if (used) {
+ *used = 0;
+ while (start < end) {
+ re = (struct fdt_reserve_entry *)(fdt + start);
+ if (re->size == 0)
+ return 0; /* zero size terminates the list */
+
+ *used += 1;
+ start += sizeof(struct fdt_reserve_entry);
+ }
+ /*
+ * If we get here, there was no zero size termination.
+ */
+ return -FDT_ERR_BADLAYOUT;
+ }
+ return 0;
+}
+
+/*
+ * Return the nth reserve map entry.
+ */
+int fdt_get_reservemap(void *fdt, int n, struct fdt_reserve_entry *re)
+{
+ int used;
+ int total;
+ int err;
+
+ err = fdt_num_reservemap(fdt, &used, &total);
+ if (err != 0)
+ return err;
+
+ if (n >= total)
+ return -FDT_ERR_NOSPACE;
+ if (re) {
+ *re = *(struct fdt_reserve_entry *)
+ _fdt_offset_ptr(fdt, n * sizeof(struct fdt_reserve_entry));
+ }
+ return 0;
+}
generated by cgit v1.1 at 2024-12-01 05:31:12 +0000