Add qemu 2.4.0

[kvmfornfv.git] / qemu / roms / u-boot / common / env_callback.c

diff --git a/qemu/roms/u-boot/common/env_callback.c b/qemu/roms/u-boot/common/env_callback.c
new file mode 100644 (file)
index 0000000..d03fa03
--- /dev/null
+++ b/qemu/roms/u-boot/common/env_callback.c
@@ -0,0 +1,135 @@
+/*
+ * (C) Copyright 2012
+ * Joe Hershberger, National Instruments, joe.hershberger@ni.com
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#include <common.h>
+#include <environment.h>
+
+#if defined(CONFIG_NEEDS_MANUAL_RELOC)
+DECLARE_GLOBAL_DATA_PTR;
+#endif
+
+/*
+ * Look up a callback function pointer by name
+ */
+static struct env_clbk_tbl *find_env_callback(const char *name)
+{
+       struct env_clbk_tbl *clbkp;
+       int i;
+       int num_callbacks = ll_entry_count(struct env_clbk_tbl, env_clbk);
+
+       if (name == NULL)
+               return NULL;
+
+       /* look up the callback in the linker-list */
+       for (i = 0, clbkp = ll_entry_start(struct env_clbk_tbl, env_clbk);
+            i < num_callbacks;
+            i++, clbkp++) {
+               if (strcmp(name, clbkp->name) == 0)
+                       return clbkp;
+       }
+
+       return NULL;
+}
+
+static int first_call = 1;
+static const char *callback_list;
+
+/*
+ * Look for a possible callback for a newly added variable
+ * This is called specifically when the variable did not exist in the hash
+ * previously, so the blanket update did not find this variable.
+ */
+void env_callback_init(ENTRY *var_entry)
+{
+       const char *var_name = var_entry->key;
+       char callback_name[256] = "";
+       struct env_clbk_tbl *clbkp;
+       int ret = 1;
+
+       if (first_call) {
+               callback_list = getenv(ENV_CALLBACK_VAR);
+               first_call = 0;
+       }
+
+       /* look in the ".callbacks" var for a reference to this variable */
+       if (callback_list != NULL)
+               ret = env_attr_lookup(callback_list, var_name, callback_name);
+
+       /* only if not found there, look in the static list */
+       if (ret)
+               ret = env_attr_lookup(ENV_CALLBACK_LIST_STATIC, var_name,
+                       callback_name);
+
+       /* if an association was found, set the callback pointer */
+       if (!ret && strlen(callback_name)) {
+               clbkp = find_env_callback(callback_name);
+               if (clbkp != NULL)
+#if defined(CONFIG_NEEDS_MANUAL_RELOC)
+                       var_entry->callback = clbkp->callback + gd->reloc_off;
+#else
+                       var_entry->callback = clbkp->callback;
+#endif
+       }
+}
+
+/*
+ * Called on each existing env var prior to the blanket update since removing
+ * a callback association should remove its callback.
+ */
+static int clear_callback(ENTRY *entry)
+{
+       entry->callback = NULL;
+
+       return 0;
+}
+
+/*
+ * Call for each element in the list that associates variables to callbacks
+ */
+static int set_callback(const char *name, const char *value)
+{
+       ENTRY e, *ep;
+       struct env_clbk_tbl *clbkp;
+
+       e.key   = name;
+       e.data  = NULL;
+       hsearch_r(e, FIND, &ep, &env_htab, 0);
+
+       /* does the env variable actually exist? */
+       if (ep != NULL) {
+               /* the assocaition delares no callback, so remove the pointer */
+               if (value == NULL || strlen(value) == 0)
+                       ep->callback = NULL;
+               else {
+                       /* assign the requested callback */
+                       clbkp = find_env_callback(value);
+                       if (clbkp != NULL)
+#if defined(CONFIG_NEEDS_MANUAL_RELOC)
+                               ep->callback = clbkp->callback + gd->reloc_off;
+#else
+                               ep->callback = clbkp->callback;
+#endif
+               }
+       }
+
+       return 0;
+}
+
+static int on_callbacks(const char *name, const char *value, enum env_op op,
+       int flags)
+{
+       /* remove all callbacks */
+       hwalk_r(&env_htab, clear_callback);
+
+       /* configure any static callback bindings */
+       env_attr_walk(ENV_CALLBACK_LIST_STATIC, set_callback);
+       /* configure any dynamic callback bindings */
+       env_attr_walk(value, set_callback);
+
+       return 0;
+}
+U_BOOT_ENV_CALLBACK(callbacks, on_callbacks);