diskOS installer: initial public beta

Flashes the diskOS custom UI onto the FiiO Snowsky Disc over Ingenic mask-ROM USB,
building the image from your own stock firmware. Runs from source via install.sh.

diskos_installer/platform_probe.py

@@ -0,0 +1,104 @@
+"""Host OS/arch detection and Snowsky-Disc device presence checks.
+
+Device USB identities we care about:
+  - Ingenic X2000 mask-ROM (flashing mode):  VID:PID 0a108:eaef  (a108:eaef)
+  - normal running device (not used for flashing) is a different id.
+
+We enumerate USB via pyusb (bundled) so we don't depend on `lsusb` being present.
+"""
+
+import platform
+import sys
+
+MASKROM_VID = 0x0a108 & 0xFFFF  # printed as a108 by lsusb; VID field is 0xa108
+MASKROM_PID = 0xeaef
+# lsusb shows "a108:eaef"; libusb reports idVendor=0xa108 idProduct=0xeaef
+MASKROM_VID = 0xa108
+
+
+def host():
+    """Return (os_key, arch_key) e.g. ('linux','x86_64') / ('macos','arm64')."""
+    sysname = platform.system().lower()
+    if sysname == "darwin":
+        os_key = "macos"
+    elif sysname == "linux":
+        os_key = "linux"
+    else:
+        os_key = sysname  # 'windows' etc. - unsupported for now
+    machine = platform.machine().lower()
+    arch = {
+        "x86_64": "x86_64", "amd64": "x86_64",
+        "arm64": "arm64", "aarch64": "arm64",
+    }.get(machine, machine)
+    return os_key, arch
+
+
+def host_tag():
+    o, a = host()
+    return f"{o}-{a}"
+
+
+def is_supported():
+    o, _ = host()
+    return o in ("linux", "macos")
+
+
+def _bundled_libusb_backend():
+    """A pyusb libusb1 backend pointed at OUR bundled libusb, so USB enumeration
+    works in the frozen app even when the system has no libusb. Returns a backend
+    or None (caller falls back to pyusb's default search)."""
+    try:
+        import glob
+        import os
+        import usb.backend.libusb1 as libusb1
+        from . import bundle
+        libdir = os.path.join(bundle.vendor_dir(), "lib")
+        # macOS dylib or Linux .so, whatever we bundled
+        for pat in ("libusb-1.0*.dylib", "libusb-1.0.so*", "libusb-1.0*"):
+            hits = sorted(glob.glob(os.path.join(libdir, pat)))
+            if hits:
+                return libusb1.get_backend(find_library=lambda _n, _p=hits[0]: _p)
+    except Exception:
+        pass
+    return None
+
+
+def _maskrom_count_pyusb():
+    """Count devices in Ingenic mask-ROM mode via pyusb. Returns int or None if
+    pyusb/backend is unavailable."""
+    try:
+        import usb.core  # pyusb (bundled)
+    except Exception:
+        return None
+    try:
+        backend = _bundled_libusb_backend()   # prefer our bundled libusb
+        devs = list(usb.core.find(find_all=True, idVendor=MASKROM_VID,
+                                  idProduct=MASKROM_PID, backend=backend))
+        return len(devs)
+    except Exception:
+        return None
+
+
+def _maskrom_count_lsusb():
+    """Fallback: parse `lsusb` if present (Linux)."""
+    import shutil
+    import subprocess
+    if not shutil.which("lsusb"):
+        return None
+    try:
+        out = subprocess.run(["lsusb"], capture_output=True, text=True, timeout=10).stdout
+    except Exception:
+        return None
+    return sum(1 for ln in out.splitlines() if "a108:eaef" in ln.lower())
+
+
+def maskrom_count():
+    """How many devices are currently in mask-ROM mode. Prefers pyusb, falls back
+    to lsusb, returns -1 if neither is available (caller should warn)."""
+    n = _maskrom_count_pyusb()
+    if n is not None:
+        return n
+    n = _maskrom_count_lsusb()
+    if n is not None:
+        return n
+    return -1