[FL-3097] fbt, faploader: minimal app module implementation (#2420)

* fbt, faploader: minimal app module implementation
* faploader, libs: moved API hashtable core to flipper_application
* example: compound api
* lib: flipper_application: naming fixes, doxygen comments
* fbt: changed `requires` manifest field behavior for app extensions
* examples: refactored plugin apps; faploader: changed new API naming; fbt: changed PLUGIN app type meaning
* loader: dropped support for debug apps & plugin menus
* moved applications/plugins -> applications/external
* Restored x bit on chiplist_convert.py
* git: fixed free-dap submodule path
* pvs: updated submodule paths
* examples: example_advanced_plugins.c: removed potential memory leak on errors
* examples: example_plugins: refined requires
* fbt: not deploying app modules for debug/sample apps; extra validation for .PLUGIN-type apps
* apps: removed cdefines for external apps
* fbt: moved ext app path definition
* fbt: reworked fap_dist handling; f18: synced api_symbols.csv
* fbt: removed resources_paths for extapps
* scripts: reworked storage
* scripts: reworked runfap.py & selfupdate.py to use new api
* wip: fal runner
* fbt: moved file packaging into separate module
* scripts: storage: fixes
* scripts: storage: minor fixes for new api
* fbt: changed internal artifact storage details for external apps
* scripts: storage: additional fixes and better error reporting; examples: using APP_DATA_PATH()
* fbt, scripts: reworked launch_app to deploy plugins; moved old runfap.py to distfap.py
* fbt: extra check for plugins descriptors
* fbt: additional checks in emitter
* fbt: better info message on SDK rebuild
* scripts: removed requirements.txt
* loader: removed remnants of plugins & debug menus
* post-review fixes

lib/flipper_application/elf/elf_api_interface.h

@@ -3,10 +3,14 @@
 #include <elf.h>
 #include <stdbool.h>
 
-#define ELF_INVALID_ADDRESS 0xFFFFFFFF
-
-typedef struct {
+/**
+ * @brief Interface for ELF loader to resolve symbols
+ */
+typedef struct ElfApiInterface {
     uint16_t api_version_major;
     uint16_t api_version_minor;
-    bool (*resolver_callback)(const char* name, Elf32_Addr* address);
+    bool (*resolver_callback)(
+        const struct ElfApiInterface* interface,
+        const char* name,
+        Elf32_Addr* address);
 } ElfApiInterface;

lib/flipper_application/elf/elf_file.c

@@ -17,6 +17,8 @@
 #define FURI_LOG_D(...)
 #endif
 
+#define ELF_INVALID_ADDRESS 0xFFFFFFFF
+
 #define TRAMPOLINE_CODE_SIZE 6
 
 /**
@@ -166,7 +168,7 @@ static ELFSection* elf_section_of(ELFFile* elf, int index) {
 static Elf32_Addr elf_address_of(ELFFile* elf, Elf32_Sym* sym, const char* sName) {
     if(sym->st_shndx == SHN_UNDEF) {
         Elf32_Addr addr = 0;
-        if(elf->api_interface->resolver_callback(sName, &addr)) {
+        if(elf->api_interface->resolver_callback(elf->api_interface, sName, &addr)) {
             return addr;
         }
     } else {
@@ -514,10 +516,13 @@ static SectionType elf_preload_section(
         section_p->sec_idx = section_idx;
 
         if(section_header->sh_type == SHT_PREINIT_ARRAY) {
+            furi_assert(elf->preinit_array == NULL);
             elf->preinit_array = section_p;
         } else if(section_header->sh_type == SHT_INIT_ARRAY) {
+            furi_assert(elf->init_array == NULL);
             elf->init_array = section_p;
         } else if(section_header->sh_type == SHT_FINI_ARRAY) {
+            furi_assert(elf->fini_array == NULL);
             elf->fini_array = section_p;
         }
 
@@ -605,10 +610,17 @@ ELFFile* elf_file_alloc(Storage* storage, const ElfApiInterface* api_interface)
     elf->api_interface = api_interface;
     ELFSectionDict_init(elf->sections);
     AddressCache_init(elf->trampoline_cache);
+    elf->init_array_called = false;
     return elf;
 }
 
 void elf_file_free(ELFFile* elf) {
+    // furi_check(!elf->init_array_called);
+    if(elf->init_array_called) {
+        FURI_LOG_W(TAG, "Init array was called, but fini array wasn't");
+        elf_file_call_section_list(elf->fini_array, true);
+    }
+
     // free sections data
     {
         ELFSectionDict_it_t it;
@@ -774,19 +786,26 @@ ELFFileLoadStatus elf_file_load_sections(ELFFile* elf) {
     return status;
 }
 
-void elf_file_pre_run(ELFFile* elf) {
+void elf_file_call_init(ELFFile* elf) {
+    furi_check(!elf->init_array_called);
     elf_file_call_section_list(elf->preinit_array, false);
     elf_file_call_section_list(elf->init_array, false);
+    elf->init_array_called = true;
 }
 
-int32_t elf_file_run(ELFFile* elf, void* args) {
-    int32_t result;
-    result = ((int32_t(*)(void*))elf->entry)(args);
-    return result;
+bool elf_file_is_init_complete(ELFFile* elf) {
+    return elf->init_array_called;
 }
 
-void elf_file_post_run(ELFFile* elf) {
+void* elf_file_get_entry_point(ELFFile* elf) {
+    furi_check(elf->init_array_called);
+    return (void*)elf->entry;
+}
+
+void elf_file_call_fini(ELFFile* elf) {
+    furi_check(elf->init_array_called);
     elf_file_call_section_list(elf->fini_array, true);
+    elf->init_array_called = false;
 }
 
 const ElfApiInterface* elf_file_get_api_interface(ELFFile* elf_file) {

lib/flipper_application/elf/elf_file.h

@@ -82,24 +82,34 @@ bool elf_file_load_section_table(ELFFile* elf_file);
 ELFFileLoadStatus elf_file_load_sections(ELFFile* elf_file);
 
 /**
- * @brief Execute ELF file pre-run stage, call static constructors for example (load stage #3)
+ * @brief Execute ELF file pre-run stage, 
+ * call static constructors for example (load stage #3)
+ * Must be done before invoking any code from the ELF file
  * @param elf 
  */
-void elf_file_pre_run(ELFFile* elf);
+void elf_file_call_init(ELFFile* elf);
 
 /**
- * @brief Run ELF file (load stage #4)
+ * @brief Check if ELF file pre-run stage was executed and its code is runnable
+ * @param elf 
+ */
+bool elf_file_is_init_complete(ELFFile* elf);
+
+/**
+ * @brief Get actual entry point for ELF file
  * @param elf_file 
  * @param args 
  * @return int32_t 
  */
-int32_t elf_file_run(ELFFile* elf_file, void* args);
+void* elf_file_get_entry_point(ELFFile* elf_file);
 
 /**
- * @brief Execute ELF file post-run stage, call static destructors for example (load stage #5)
+ * @brief Execute ELF file post-run stage, 
+ * call static destructors for example (load stage #5)
+ * Must be done if any code from the ELF file was executed
  * @param elf 
  */
-void elf_file_post_run(ELFFile* elf);
+void elf_file_call_fini(ELFFile* elf);
 
 /**
  * @brief Get ELF file API interface

lib/flipper_application/elf/elf_file_i.h

@@ -45,6 +45,8 @@ struct ELFFile {
     ELFSection* preinit_array;
     ELFSection* init_array;
     ELFSection* fini_array;
+
+    bool init_array_called;
 };
 
 #ifdef __cplusplus