Implement posix app loading (#643)

- Added POSIX desktop support for SDK builds, application packaging, and integration testing.
- Added POSIX filesystem partitions and improved application path handling.
- Added simulator support for loading and running applications dynamically.
- Improved simulator task stack handling and display startup reliability.
- Improved simulator display scaling, resizing, high-DPI support, and pointer accuracy.
- Fixed LVGL timers and input polling on POSIX. (fixes simulator with Linux on some Intel graphics platforms)
- Standardized data paths across platforms.
- Logging now works via separate task: this allows apps to write to log without it affecting their stdout (for apps that output text as relevant date for other apps, like the File Selection app)
- Fixes for app stdio

Tactility/CMakeLists.txt

@@ -88,6 +88,7 @@ else ()
 
     list(APPEND REQUIRES_LIST
         platform-posix
+        app-posix-module
         freertos_kernel
         cJSON
         lvgl
@@ -181,6 +182,34 @@ else ()
     target_include_directories(Tactility PUBLIC Include/)
     target_include_directories(Tactility PRIVATE Private/)
     target_link_libraries(Tactility PRIVATE ${TACTILITY_REQUIRES_LIST})
+    # Exports Tactility's own symbols (-rdynamic) so a dlopen()ed app-posix-module app can resolve
+    # calls back into it - the OS-native equivalent of app-esp32-module's custom symbol resolver.
+    set_target_properties(Tactility PROPERTIES ENABLE_EXPORTS ON)
+    # Routes every pthread_attr_setstack() call (FreeRTOS's POSIX port hands each task a stack
+    # carved out of its own heap through this) to __wrap_pthread_attr_setstack() in
+    # Platforms/platform-posix/source/pthread_stack_wrap.c, which no-ops it - see that file for why.
+    # --wrap is a GNU ld option; Apple's linker doesn't support it.
+    if (NOT APPLE)
+        target_link_options(Tactility PRIVATE "-Wl,--wrap=pthread_attr_setstack")
+        # Routes every read()/write()/close() call to Tactility/Source/AppStdioWrap.cpp's
+        # __wrap_read/write/close(), which forward into app_io_read/write/close() - the fd-table
+        # dispatch that lets an app's own stdio (e.g. a fileselection dialog's printf'd result
+        # path) reach an AppStream a parent bound via app_manager_start_with_streams(). Mirrors
+        # what ESP-IDF's build already does for the ESP32 target (see top-level CMakeLists.txt).
+        target_link_options(Tactility PRIVATE "-Wl,--wrap=read" "-Wl,--wrap=write" "-Wl,--wrap=close")
+        # glibc's printf/fprintf/etc don't call the public write() symbol internally (they're
+        # already compiled into libc.so, out of --wrap's reach), so the read/write/close wrap
+        # above can't see them. Newlib (ESP-IDF) doesn't have this gap - its stdio does call the
+        # wrappable syscall stubs - so this block is POSIX-only. Wrapping these symbols instead
+        # redirects OUR OWN calls to them (the only ones --wrap can rewrite) through
+        # AppStdioWrap.cpp's __wrap_* functions, which check the target stream (stdout/stdin) and
+        # fall back to the real libc function for any other FILE*.
+        target_link_options(Tactility PRIVATE
+            "-Wl,--wrap=printf" "-Wl,--wrap=fprintf" "-Wl,--wrap=vprintf" "-Wl,--wrap=vfprintf"
+            "-Wl,--wrap=puts" "-Wl,--wrap=fputs" "-Wl,--wrap=putchar" "-Wl,--wrap=fputc"
+            "-Wl,--wrap=getchar" "-Wl,--wrap=fgetc" "-Wl,--wrap=fgets"
+        )
+    endif ()
 endif ()
 
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