WebSVN – HelenOS – Diff – /trunk/boot/genarch/ofw_tree.c

 /** Transfer information from one OpenFirmware node into its memory representation.
+ *
  * Transfer entire information from the OpenFirmware device tree 'current' node to
  * its memory representation in 'current_node'. This function recursively processes
+ * all node's children. Node's peers are processed iteratively in order to prevent
- * all node's peers and children.
+ * stack from overflowing.
+ *
  * @param current_node  Pointer to uninitialized ofw_tree_node structure that will
  *          become the memory represenation of 'current'.
  * @param parent_node   Parent ofw_tree_node structure or NULL in case of root node.
  * @param current   OpenFirmware phandle to the current device tree node.
+{
     static char path[MAX_PATH_LEN+1];
     static char name[OFW_TREE_PROPERTY_MAX_NAMELEN];
     phandle peer;
     phandle child;
-    unsigned properties = 0;
     size_t len;
     int i;
+    while (current_node) {
-    /*
+        /*
-     * Initialize node.
+         * Initialize node.
-     */
+         */
-    current_node->parent = parent_node;
+        current_node->parent = parent_node;
-    current_node->peer = NULL;
+        current_node->peer = NULL;
-    current_node->child = NULL;
+        current_node->child = NULL;
-    current_node->node_handle = current;
+        current_node->node_handle = current;
-    current_node->properties = 0;
+        current_node->properties = 0;
-    current_node->property = NULL;
+        current_node->property = NULL;
-    current_node->device = NULL;
+        current_node->device = NULL;
-    /*
+        /*
-     * Get the disambigued name.
+         * Get the disambigued name.
-     */
+         */
-    len = ofw_package_to_path(current, path, MAX_PATH_LEN);
+        len = ofw_package_to_path(current, path, MAX_PATH_LEN);
-    if (len == -1)
+        if (len == -1)
-        return;
+            return;
-    path[len] = '\0';
+        path[len] = '\0';
-    for (i = len - 1; i >= 0 && path[i] != '/'; i--)
+        for (i = len - 1; i >= 0 && path[i] != '/'; i--)
-        ;
+            ;
-    i++;                                /* do not include '/' */
+        i++;    /* do not include '/' */
-    len -= i;
-    current_node->da_name = ofw_tree_space_alloc(len + 1);      /* add space for trailing '\0' */
-    if (!current_node->da_name)
-        return;
-    memcpy(current_node->da_name, &path[i], len);
-    current_node->da_name[len] = '\0';
-    /*
-     * Recursively process the potential peer node.
-     */
-    peer = ofw_get_peer_node(current);
-    if (peer != 0 && peer != -1) {
-        ofw_tree_node_t *peer_node;
-        peer_node = ofw_tree_node_alloc();
-        if (peer_node) {
-            ofw_tree_node_process(peer_node, parent_node, peer);
-            current_node->peer = peer_node;
-        }
-    }
+        len -= i;
+        /* add space for trailing '\0' */
+        current_node->da_name = ofw_tree_space_alloc(len + 1);
+        if (!current_node->da_name)
+            return;
+        memcpy(current_node->da_name, &path[i], len);
+        current_node->da_name[len] = '\0';
-    /*
+        /*
-     * Recursively process the potential child node.
+         * Recursively process the potential child node.
-     */
+         */
-    child = ofw_get_child_node(current);
+        child = ofw_get_child_node(current);
-    if (child != 0 && child != -1) {
+        if (child != 0 && child != -1) {
-        ofw_tree_node_t *child_node;
+            ofw_tree_node_t *child_node;
-        child_node = ofw_tree_node_alloc();
+            child_node = ofw_tree_node_alloc();
-        if (child_node) {
+            if (child_node) {
-            ofw_tree_node_process(child_node, current_node, child);
+                ofw_tree_node_process(child_node, current_node, child);
-            current_node->child = child_node;
+                current_node->child = child_node;
+            }
+        }
-    }
-    /*
+        /*
-     * Count properties.
+         * Count properties.
-     */
+         */
-    name[0] = '\0';
+        name[0] = '\0';
-    while (ofw_next_property(current, name, name) == 1)
+        while (ofw_next_property(current, name, name) == 1)
-        current_node->properties++;
+            current_node->properties++;
-    if (!current_node->properties)
+        if (!current_node->properties)
-        return;
+            return;
-    /*
+        /*
-     * Copy properties.
+         * Copy properties.
-     */
+         */
-    current_node->property = ofw_tree_properties_alloc(current_node->properties);
+        current_node->property = ofw_tree_properties_alloc(current_node->properties);
-    if (!current_node->property)
+        if (!current_node->property)
-        return;
+            return;
-    name[0] = '\0';
+        name[0] = '\0';
-    for (i = 0; ofw_next_property(current, name, name) == 1; i++) {
+        for (i = 0; ofw_next_property(current, name, name) == 1; i++) {
-        size_t size;
+            size_t size;
-        if (i == current_node->properties)
+            if (i == current_node->properties)
-            break;
+                break;
-        memcpy(current_node->property[i].name, name, OFW_TREE_PROPERTY_MAX_NAMELEN);
+            memcpy(current_node->property[i].name, name,
+                OFW_TREE_PROPERTY_MAX_NAMELEN);
-        current_node->property[i].name[OFW_TREE_PROPERTY_MAX_NAMELEN] = '\0';
+            current_node->property[i].name[OFW_TREE_PROPERTY_MAX_NAMELEN] = '\0';
-        size = ofw_get_proplen(current, name);
+            size = ofw_get_proplen(current, name);
-        current_node->property[i].size = size;
+            current_node->property[i].size = size;
-        if (size) {
+            if (size) {
-            void *buf;
+                void *buf;
-            buf = ofw_tree_space_alloc(size);
+                buf = ofw_tree_space_alloc(size);
-            if (current_node->property[i].value = buf) {
+                if (current_node->property[i].value = buf) {
+                    /*
+                     * Copy property value to memory node.
+                     */
+                    (void) ofw_get_property(current, name, buf, size);
+                }
+            } else {
+                current_node->property[i].value = NULL;
+            }
+        }
+        current_node->properties = i;   /* Just in case we ran out of memory. */
+        /*
+         * Iteratively process the next peer node.
+         * Note that recursion is a bad idea here.
+         * Due to the topology of the OpenFirmware device tree,
+         * the nesting of peer nodes could be to wide and the
+         * risk of overflowing the stack is too real.
+         */
+        peer = ofw_get_peer_node(current);
+        if (peer != 0 && peer != -1) {
+            ofw_tree_node_t *peer_node;
+            peer_node = ofw_tree_node_alloc();
+            if (peer_node) {
+                current_node->peer = peer_node;
+                current_node = peer_node;
+                current = peer;
                 /*
-                 * Copy property value to memory node.
+                 * Process the peer in next iteration.
                  */
-                (void) ofw_get_property(current, name, buf, size);
+                continue;
+            }
-        } else {
-            current_node->property[i].value = NULL;
+        }
+        /*
+         * No more peers on this level.
+         */
+        break;
+    }
-    current_node->properties = i;   /* Just in case we ran out of memory. */
+}
 /** Construct memory representation of OpenFirmware device tree.
+ *
  * @return NULL on failure or pointer to the root node.

Subversion Repositories HelenOS

(root)/trunk/boot/genarch/ofw_tree.c – Rev 1909 → 1973