diff options
Diffstat (limited to 'libfdt/fdt_ro.c')
| -rw-r--r-- | libfdt/fdt_ro.c | 116 |
1 files changed, 110 insertions, 6 deletions
diff --git a/libfdt/fdt_ro.c b/libfdt/fdt_ro.c index 9112c6a63..f88408395 100644 --- a/libfdt/fdt_ro.c +++ b/libfdt/fdt_ro.c @@ -48,11 +48,24 @@ static int offset_streq(const void *fdt, int offset, 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) { @@ -62,13 +75,13 @@ int fdt_subnode_offset_namelen(const void *fdt, int parentoffset, CHECK_HEADER(fdt); - tag = _fdt_next_tag(fdt, parentoffset, &nextoffset); + 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); + tag = fdt_next_tag(fdt, offset, &nextoffset, NULL); switch (tag) { case FDT_END: @@ -76,10 +89,15 @@ int fdt_subnode_offset_namelen(const void *fdt, int parentoffset, 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)) - /* Found it! */ return offset; break; @@ -99,12 +117,19 @@ int fdt_subnode_offset_namelen(const void *fdt, int parentoffset, 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); @@ -113,21 +138,33 @@ int fdt_path_offset(const void *fdt, const char *path) 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; @@ -137,6 +174,10 @@ int fdt_path_offset(const void *fdt, const char *path) 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) @@ -155,14 +196,14 @@ struct fdt_property *fdt_get_property(const void *fdt, if (nodeoffset % FDT_TAGSIZE) goto fail; - tag = _fdt_next_tag(fdt, nodeoffset, &nextoffset); + 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); + tag = fdt_next_tag(fdt, offset, &nextoffset, NULL); switch (tag) { case FDT_END: err = -FDT_ERR_TRUNCATED; @@ -177,6 +218,10 @@ struct fdt_property *fdt_get_property(const void *fdt, 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; @@ -216,6 +261,10 @@ struct fdt_property *fdt_get_property(const void *fdt, 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) { @@ -225,5 +274,60 @@ void *fdt_getprop(const void *fdt, int nodeoffset, if (! prop) return NULL; - return prop->data; + 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; +} + |