Add support for errno in plugins.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@24109 a1c6a512-1295-4272-9138-f99709370657

apps/plugin.c

@@ -40,6 +40,7 @@
 #include "version.h"
 #include "storage.h"
 #include "pcmbuf.h"
+#include "errno.h"
 
 #if CONFIG_CHARGING
 #include "power.h"
@@ -680,6 +681,7 @@ static const struct plugin_api rockbox_api = {
     viewportmanager_theme_enable,
     viewportmanager_theme_undo,
 #endif
+    &errno
 };
 
 int plugin_load(const char* plugin, const void* parameter)

apps/plugin.h

@@ -860,6 +860,7 @@ struct plugin_api {
                                          struct viewport *viewport);
     void (*viewportmanager_theme_undo)(enum screen_type screen, bool force_redraw);
 #endif
+    int* __errno;
 };
 
 /* plugin header */

firmware/include/errno.h

@@ -10,7 +10,11 @@
 
 #ifndef _SYS_ERRNO_H_
 
+#ifdef PLUGIN
+#define errno   (*rb->__errno)
+#else
 extern int errno;
+#endif
 
 #define	EPERM 1		/* Not super-user */
 #define	ENOENT 2	/* No such file or directory */