[add] Using 'ledgered' to extract metadata from the application elf

Pipfile

@@ -15,6 +15,7 @@ pillow = ">=8.0.0,<11.0.0"
 pyelftools = ">=0.27,<1.0"
 pyqt5 = ">=5.15.2,<6.0.0"
 requests = ">=2.25.1,<3.0.0"
+ledgered = ">=0.6.2"
 
 [requires]
 python_version = "3.9"

pyproject.toml

@@ -32,6 +32,7 @@ dependencies = [
     "pyelftools>=0.27,<1.0",
     "pyqt5>=5.15.2,<6.0.0",
     "requests>=2.25.1,<3.0.0",
+    "ledgered>=0.6.2",
 ]
 dynamic = ["version"]
 

speculos/main.py

@@ -16,6 +16,7 @@
 import threading
 import pkg_resources
 from elftools.elf.elffile import ELFFile
+from ledgered.binary import LedgerBinaryApp
 from mnemonic import mnemonic
 from typing import Optional, Type
 
@@ -48,28 +49,6 @@ def set_pdeath(sig):
     libc.prctl(PR_SET_PDEATHSIG, sig)
 
 
-ELF_METADATA_SECTIONS = [
-    "target",
-    "app_name",
-    "app_version",
-    "api_level"
-]
-
-
-def get_elf_ledger_metadata(app_path):
-    with open(app_path, 'rb') as fp:
-        elf = ELFFile(fp)
-        metadata = {}
-        for section_name in ELF_METADATA_SECTIONS:
-            section = elf.get_section_by_name(f"ledger.{section_name}")
-            if section:
-                metadata[section_name] = section.data().decode("utf-8").strip()
-                if section_name == "target":
-                    if metadata[section_name] == "nanos2":
-                        metadata[section_name] = "nanosp"
-    return metadata
-
-
 def get_elf_infos(app_path):
     with open(app_path, 'rb') as fp:
         elf = ELFFile(fp)
@@ -140,21 +119,6 @@ def get_cx_infos(app_path):
     return sh_offset, sh_size, sh_load, cx_ram_size, cx_ram_load
 
 
-def get_elf_fonts_size(app_path):
-    '''
-    Check for C_bagl_fonts symbol to determine if the app use BAGL or NBGL syscalls.
-    If C_bagl_fonts is found, it means that this app uses BAGL (useful on NanoX and NanoSP)
-    '''
-    with open(app_path, 'rb') as fp:
-        elf = ELFFile(fp)
-        symtab = elf.get_section_by_name('.symtab')
-        bagl_fonts_symbol = symtab.get_symbol_by_name('C_bagl_fonts')
-        if bagl_fonts_symbol is not None:
-            return bagl_fonts_symbol[0]['st_size']
-
-    return 0
-
-
 def run_qemu(s1: socket.socket, s2: socket.socket, args: argparse.Namespace, use_bagl: bool) -> int:
     argv = ['qemu-arm-static']
 
@@ -335,24 +299,25 @@ def main(prog=None) -> int:
 
     # Init model and api_level if not specified from app elf metadata
     app_path = getattr(args, 'app.elf')
-    metadata = get_elf_ledger_metadata(app_path)
+    binary = LedgerBinaryApp(app_path)
     if not args.model:
-        if "target" not in metadata:
+        if binary.sections.target is None:
             logger.error("Device model not detected from elf. Then it must be specified")
             sys.exit(1)
         else:
-            args.model = metadata["target"]
+            args.model = "nanosp" if binary.sections.target == "nanos2" else binary.sections.target
             logger.warn(f"Device model detected from metadata: {args.model}")
 
-    # For Nano S and Blue, it can only be BAGL
-    if args.model == "nanos" or args.model == "blue":
-        use_bagl = True
+    # 'bagl' is the default value of the binary.sections.sdk_graphics. We need to
+    # manage the cases where it is NOT 'bagl' but the section does not exists yet
+    if args.model in ["stax", "flex"]:
+        use_bagl = False
     else:
-        use_bagl = get_elf_fonts_size(app_path) != 0
+        use_bagl = binary.sections.sdk_graphics == "bagl"
 
     if not args.apiLevel:
-        if "api_level" in metadata:
-            args.apiLevel = metadata["api_level"]
+        if binary.sections.api_level is not None:
+            args.apiLevel = binary.sections.api_level
             logger.warn(f"Api level detected from metadata: {args.apiLevel}")
 
     # Check args.apiLevel, 0 is an invalid value
@@ -362,8 +327,8 @@ def main(prog=None) -> int:
 
     # Set SPECULOS_DETECTED_APPNAME env variable for proper emulation.
     # See sys_os_registry_get_current_app_tag() for corresponding usage.
-    app_name = metadata.get("app_name")
-    app_version = metadata.get("app_version")
+    app_name = binary.sections.app_name
+    app_version = binary.sections.app_version
     if app_name and app_version:
         os.environ["SPECULOS_DETECTED_APPNAME"] = f"{app_name}:{app_version}"
 
@@ -376,8 +341,7 @@ def main(prog=None) -> int:
             lib_name = None
             lib_path = lib_arg
 
-        metadata = get_elf_ledger_metadata(lib_path)
-        elf_lib_name = metadata.get("app_name", None)
+        elf_lib_name = LedgerBinaryApp(lib_path).sections.app_name
 
         if lib_name is None:
             if elf_lib_name is None:
@@ -396,14 +360,14 @@ def main(prog=None) -> int:
 
     # Check model and api_level against all lib elf metadata
     for path in [app_path] + [x.split(":")[1] for x in args.library]:
-        metadata = get_elf_ledger_metadata(path)
+        binary = LedgerBinaryApp(path)
 
-        elf_model = metadata.get("target", args.model)
+        elf_model = ("nanosp" if binary.sections.target == "nanos2" else binary.sections.target) or args.model
         if args.model != elf_model:
             logger.error(f"Invalid model in {path} ({elf_model} vs {args.model})")
             sys.exit(1)
 
-        elf_api_level = metadata.get("api_level", "0")
+        elf_api_level = binary.sections.api_level or "0"
         # Check args.apiLevel against elf api level. If elf api level == 0 (SDK master
         # reserved value) ignore it.
         if elf_api_level != "0" and args.apiLevel != elf_api_level: