Introduce plugin_crt0.c that every plugin links.

It handles exit() properly, calling the handler also when the plugin returns
normally (also it makes exit() more standard compliant while at it).
It also holds PLUGIN_HEADER, so that it doesn't need to be in each plugin anymore.

To work better together with callbacks passed to rb->default_event_handler_ex introduce exit_on_usb() which will call the exit handler before showing the usb screen and exit() after it.
In most cases it was passed a callback which was manually called at all other return points. This can now be done via atexit().

In future plugin_crt0.c could also handle clearing bss, initializing iram and more.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@27862 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 9 insertions, 5 deletions

diff --git a/apps/plugin.h b/apps/plugin.h
index 624b7039b8..cb6cc83089 100644
--- a/apps/plugin.h
+++ b/apps/plugin.h
@@ -155,9 +155,13 @@ void* plugin_get_buffer(size_t *buffer_size);
 #define PLUGIN_MIN_API_VERSION 190
 
 /* plugin return codes */
+/* internal returns start at 0x100 to make exit(1..255) work */
+#define INTERNAL_PLUGIN_RETVAL_START 0x100
 enum plugin_status {
-    PLUGIN_OK = 0,
-    PLUGIN_USB_CONNECTED,
+    PLUGIN_OK = 0, /* PLUGIN_OK == EXIT_SUCCESS */
+    /* 1...255 reserved for exit() */
+    PLUGIN_USB_CONNECTED = INTERNAL_PLUGIN_RETVAL_START,
+    PLUGIN_POWEROFF,
     PLUGIN_GOTO_WPS,
     PLUGIN_ERROR = -1,
 };
@@ -912,14 +916,14 @@ extern unsigned char plugin_end_addr[];
         const struct plugin_header __header \
         __attribute__ ((section (".header")))= { \
         PLUGIN_MAGIC, TARGET_ID, PLUGIN_API_VERSION, \
-        plugin_start_addr, plugin_end_addr, plugin_start, &rb };
+        plugin_start_addr, plugin_end_addr, plugin__start, &rb };
 #else /* PLATFORM_HOSTED */
 #define PLUGIN_HEADER \
         const struct plugin_api *rb DATA_ATTR; \
         const struct plugin_header __header \
         __attribute__((visibility("default"))) = { \
         PLUGIN_MAGIC, TARGET_ID, PLUGIN_API_VERSION, \
-        NULL, NULL, plugin_start, &rb };
+        NULL, NULL, plugin__start, &rb };
 #endif /* CONFIG_PLATFORM */
 
 #ifdef PLUGIN_USE_IRAM
@@ -954,7 +958,7 @@ void plugin_tsr(bool (*exit_callback)(bool reenter));
 
 /* defined by the plugin */
 extern const struct plugin_api *rb;
-enum plugin_status plugin_start(const void* parameter)
+enum plugin_status plugin__start(const void* parameter)
     NO_PROF_ATTR;
 
 #endif /* __PCTOOL__ */