Embed assets in elf file (#2466)

* FBT: file_assets generator
* Elf file: process manifest section externally
* FBT, file_assets generator: add assets signature
* Storage: assets path alias
* Flipper application: assets unpacker
* Apps, Storage: use '/data' alias for apps data
* Storage: copy file to file
* Assets: log flag, fixes
* Update f18 api
* Assets: asserts
* Assets: fix signature_data check
* App assets: example
* Example assets: fix folder structure in readme
* Assets: fix error handling
* Assets builder: use ansii instead of utf-8, use .fapassets section instead of .fapfiles, add assets path to signature
* Elf file: comment strange places
* Storage: totaly optimized storage_file_copy_to_file

lib/flipper_application/flipper_application.c

@@ -1,6 +1,7 @@
 #include "flipper_application.h"
 #include "elf/elf_file.h"
 #include <notification/notification_messages.h>
+#include "application_assets.h"
 
 #define TAG "fapp"
 
@@ -55,24 +56,83 @@ static FlipperApplicationPreloadStatus
     return FlipperApplicationPreloadStatusSuccess;
 }
 
-/* Parse headers, load manifest */
-FlipperApplicationPreloadStatus
-    flipper_application_preload_manifest(FlipperApplication* app, const char* path) {
-    if(!elf_file_open(app->elf, path) || !elf_file_load_manifest(app->elf, &app->manifest)) {
+static bool flipper_application_process_manifest_section(
+    File* file,
+    size_t offset,
+    size_t size,
+    void* context) {
+    FlipperApplicationManifest* manifest = context;
+
+    if(size < sizeof(FlipperApplicationManifest)) {
+        return false;
+    }
+
+    if(manifest == NULL) {
+        return true;
+    }
+
+    return storage_file_seek(file, offset, true) &&
+           storage_file_read(file, manifest, size) == size;
+}
+
+// we can't use const char* as context because we will lose the const qualifier
+typedef struct {
+    const char* path;
+} FlipperApplicationPreloadAssetsContext;
+
+static bool flipper_application_process_assets_section(
+    File* file,
+    size_t offset,
+    size_t size,
+    void* context) {
+    FlipperApplicationPreloadAssetsContext* preload_context = context;
+    return flipper_application_assets_load(file, preload_context->path, offset, size);
+}
+
+static FlipperApplicationPreloadStatus
+    flipper_application_load(FlipperApplication* app, const char* path, bool load_full) {
+    if(!elf_file_open(app->elf, path)) {
+        return FlipperApplicationPreloadStatusInvalidFile;
+    }
+
+    // if we are loading full file
+    if(load_full) {
+        // load section table
+        if(!elf_file_load_section_table(app->elf)) {
+            return FlipperApplicationPreloadStatusInvalidFile;
+        }
+
+        // load assets section
+        FlipperApplicationPreloadAssetsContext preload_context = {.path = path};
+        if(elf_process_section(
+               app->elf,
+               ".fapassets",
+               flipper_application_process_assets_section,
+               &preload_context) == ElfProcessSectionResultCannotProcess) {
+            return FlipperApplicationPreloadStatusInvalidFile;
+        }
+    }
+
+    // load manifest section
+    if(elf_process_section(
+           app->elf, ".fapmeta", flipper_application_process_manifest_section, &app->manifest) !=
+       ElfProcessSectionResultSuccess) {
         return FlipperApplicationPreloadStatusInvalidFile;
     }
 
     return flipper_application_validate_manifest(app);
 }
 
+/* Parse headers, load manifest */
+FlipperApplicationPreloadStatus
+    flipper_application_preload_manifest(FlipperApplication* app, const char* path) {
+    return flipper_application_load(app, path, false);
+}
+
 /* Parse headers, load full file */
 FlipperApplicationPreloadStatus
     flipper_application_preload(FlipperApplication* app, const char* path) {
-    if(!elf_file_open(app->elf, path) || !elf_file_load_section_table(app->elf, &app->manifest)) {
-        return FlipperApplicationPreloadStatusInvalidFile;
-    }
-
-    return flipper_application_validate_manifest(app);
+    return flipper_application_load(app, path, true);
 }
 
 const FlipperApplicationManifest* flipper_application_get_manifest(FlipperApplication* app) {