Merge pull request #115 from ddvk/notifyonupdate

hook the notify function for the screenshare #71

README.md

@@ -66,6 +66,7 @@ Xochitl function name | Xochitl function role | Notes
 `wait` | Waits until the update-handling threads have started. This function is replaced by the client shim with a no-op to avoid conflicting with the server. | Calls `usleep(1000)`.
 `shutdown` | Stops the update-handling threads. This function is replaced by the client shim with a no-op to avoid conflicting with the server. | Uses the string `Shutting down...`.
 `getInstance` | Retrieves the instance of the singleton SWTCON class. This function is used by the server to interact with the screen. | Calls a function that itself calls `create` and `wait`.
+`notify` | Called when the framebuffer has been updated, used for the Qt signal/slot connections needed for ScreenShare to work | 
 
 The client and the server both ship the [hardcoded addresses](https://github.com/ddvk/remarkable2-framebuffer/blob/master/src/shared/config.cpp#L13) for these functions for various releases.
 If you get a message saying `Missing address for function […]`, it means that the release you’re running is not yet supported. Please report this in [this dedicated thread](https://github.com/ddvk/remarkable2-framebuffer/issues/18).

src/client/main.cpp

@@ -247,7 +247,10 @@ bool _Z7qputenvPKcRK10QByteArray(const char *name, const QByteArray &val) {
   return orig_fn(name, val);
 }
 
-void new_update_int4(void*, int x1, int y1, int x2, int y2, int waveform, int flags) {
+// called when the framebuffer is updated
+typedef uint32_t (*NotifyFunc)(void*, void*);
+NotifyFunc f_notify = 0;
+void new_update_int4(void* arg, int x1, int y1, int x2, int y2, int waveform, int flags) {
 #ifdef DEBUG
   std::cerr << "UPDATE HOOK CALLED" << std::endl;
   std::cerr << "x " << x1 << " " << x2 << std::endl;
@@ -263,6 +266,11 @@ void new_update_int4(void*, int x1, int y1, int x2, int y2, int waveform, int fl
   data.waveform = waveform;
   data.flags = flags;
   MSGQ.send(data);
+
+  if (f_notify != 0) {
+    QRect someRect(x1,y1, x2-x1, y2-y1) ;
+    f_notify(arg, &someRect);
+  }
 }
 
 void new_update_QRect(void* arg, QRect& rect, int waveform, bool flags) {
@@ -346,6 +354,13 @@ void intercept_xochitl(const Config& config) {
   replace_func(interceptor, config, "create", (void*) new_create_threads);
   replace_func(interceptor, config, "shutdown", (void*) new_shutdown);
   replace_func(interceptor, config, "wait", (void*) new_wait);
+
+  auto search = config.find("notify");
+  if (search == config.end()) {
+    std::cerr << "missing notify function, screenshare won't work" << std::endl;
+  } else {
+    f_notify = (NotifyFunc) std::get<void*>(search->second);
+  }
 }
 
 __attribute__((visibility("default")))

src/shared/config.cpp

@@ -352,6 +352,7 @@ create addr 0x4e7520
 shutdown addr 0x4e74b8
 wait addr 0x4e64c0
 getInstance addr 0x4db484
+notify addr 0x4d98a4
 
 )CONF";
 

tutorial/README.md

@@ -36,6 +36,7 @@ Before starting this tutorial, [download and install Ghidra](https://www.ghidra-
      - ![Search Memory](images/05-search-memory.png)
    - in "Search Value", put the *exact* search string with no typos. Partial search is okay, just be aware you might find partial string matches in other sections of code
      - `update` search string: `Unable to complete update: invalid waveform (`
+     - `notify` is the second function in the switch, case 8 in the `update` function
      - `create` search string: `Unable to start generator thread\n`
      - `shutdown` search string: `Shutting down...`
    - Click "Next". You should only find one result.