Allow manually specifying the sdmc NRO path with --sdmc

This allows the user to not require the NRO path to be on the Switch's microSD card and can instead be anywhere on their PC or any other storage.

The --sdmc MUST be the full path to where the NRO file is on the Switch's microSD card, excluding any drive letter. You don't need to start it with `sdmc:/`.
This is effectively the path to the NRO file that the NSP will load.

The NRO path must still exist and be an NRO file. It is expected to be the same NRO file that the manual --sdmc specifies.

nton/main.py

@@ -44,6 +44,7 @@ def main(version: bool, debug: bool) -> None:
 @click.option("-i", "--icon", type=Path, default=None, help="Title Icon (256x256px recommended, supports any image).")
 @click.option("--id", "id_", type=str, default=None, help="Title ID.")
 @click.option("--rom", type=str, default=None, help="ROM path for Direct RetroArch Game Forwarding.")
+@click.option("--sdmc", type=str, default=None, help="NRO path relative to the root of the Switch's microSD card.")
 def build(
     path: Path,
     name: str | None,
@@ -51,7 +52,8 @@ def build(
     version: str | None,
     icon: Path | None,
     id_: str | None,
-    rom: str | None
+    rom: str | None,
+    sdmc: str | None
 ) -> int:
     """
     Build an NSP that loads an NRO on the Switch's microSD card.
@@ -67,6 +69,8 @@ def build(
             same Title ID as another installed Title, but it's so miniscule you shouldn't realistically worry about it.
         rom: Path to a ROM file on the Switch's microSD card to create a forwarder that boots directly into the game
             using RetroArch. The NRO path must be to a RetroArch Core. It must also be an absolute path.
+        sdmc: Path to the NRO path relative to the root of the Switch's microSD card. This should only be used if the
+            NRO path you provided is NOT on the microSD card, as it is implicitly inferred.
     """
     log = logging.getLogger("build")
     log.info("Building!")
@@ -79,11 +83,20 @@ def build(
         log.error(f"The NRO path \"{path}\" is not to an NRO file.")
         return 1
 
-    # TODO: Improve this check by using win32 calls to see if the drive is a removable drive or not.
-    #       Perhaps there's also a way to see if it's specifically an SD card, but it might not be reliable.
-    if path.drive == "C":
-        log.error(f"The NRO path must be a path on your Switch's microSD card.")
-        return 1
+    if sdmc:
+        if not sdmc.startswith("sdmc:/"):
+            if not sdmc.startswith("/"):
+                sdmc = f"/{sdmc}"
+            sdmc = f"sdmc:{sdmc}"
+    else:
+        # TODO: Improve this check by using win32 calls to see if the drive is a removable drive or not.
+        #       Perhaps there's also a way to see if it's specifically an SD card, but it might not be reliable.
+        if path.drive == "C":
+            log.error("The NRO path must be a path on your Switch's microSD card to implicitly infer the sdmc path.")
+            log.error("You can use --sdmc to manually specify the path relative to the Switch's microSD card.")
+            return 1
+        # only works if the path is on the Switch's microSD card, or the relative path matches the microSD card
+        sdmc = str(path.resolve().absolute()).replace(f"{path.drive}:/", "sdmc:/")
 
     verification = nstool.verify(path, "nro")
     if verification:
@@ -104,6 +117,8 @@ def build(
             log.warning(f"The Title ID \"{id_}\" is already used by \"{title_ids.game_title_ids[id_]}\".")
     elif path.stem.lower() in title_ids.unofficial:
         id_ = title_ids.unofficial[path.stem.lower()]
+    elif sdmc and Path(sdmc).stem.lower() in title_ids.unofficial:
+        id_ = title_ids.unofficial[Path(sdmc).stem.lower()]
     else:
         id_ = "0100000000000000"
         while id_ in title_ids.ALL:
@@ -112,7 +127,7 @@ def build(
     if rom:
         if not rom.startswith("/"):
             rom = f"/{rom}"
-        if not str(path).lower().startswith(f"{path.drive.lower()}:/retroarch/cores/"):
+        if "/retroarch/cores/" not in (str(path) + str(sdmc)).lower():
             log.error(f"Setting a ROM path for the forwarder requires the NRO path to be to a RetroArch Core.")
             log.error(f"Make sure you set it to a RetroArch Core and not to RetroArch itself or any other NRO.")
             return 1
@@ -220,7 +235,7 @@ def build(
             log.critical(f"Failed to convert and strip the Icon, {e.output} [{e.returncode}]")
             return 2
 
-        next_nro_path = str(path.resolve().absolute()).replace(f"{path.drive}:/", "sdmc:/")
+        next_nro_path = sdmc
         next_nro_path_file.write_text(next_nro_path)
 
         next_argv = next_nro_path