Add a few warning comments about the INIT_ATTR stuff.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@25024 a1c6a512-1295-4272-9138-f99709370657

apps/main.c

@@ -127,6 +127,10 @@ static void init(void);
 #ifdef SIMULATOR
 void app_main(void)
 #else
+/* main(), and various functions called by main() and init() may be
+ * be INIT_ATTR. These functions must not be called after the final call
+ * to root_menu() at the end of main()
+ * see definition of INIT_ATTR in config.h */
 int main(void)  INIT_ATTR __attribute__((noreturn));
 int main(void)
 #endif
@@ -161,6 +165,8 @@ int main(void)
 #endif /* #ifdef AUTOROCK */
 
     global_status.last_volume_change = 0;
+    /* no calls INIT_ATTR functions after this point anymore!
+     * see definition of INIT_ATTR in config.h */
     root_menu();
 }
 

firmware/export/config.h

@@ -748,6 +748,16 @@ Lyre prototype 1 */
 #define STATICIRAM static
 #endif
 #if (defined(CPU_PP) || (CONFIG_CPU == AS3525)) && !defined(SIMULATOR) && !defined(BOOTLOADER)
+/* Functions that have INIT_ATTR attached are NOT guaranteed to survive after
+ * root_menu() has been called. Their code may be overwritten by other data or
+ * code in order to save RAM, and references to them might point into
+ * zombie area.
+ *
+ * It is critical that you make sure these functions are only called before
+ * the final call to root_menu() (see apps/main.c) is called (i.e. basically
+ * only while main() runs), otherwise things may go wild,
+ * from crashes to freezes to exploding daps.
+ */
 #define INIT_ATTR       __attribute__ ((section(".init")))
 #define HAVE_INIT_ATTR
 #else