Initial import of ViperOS

Scripts/check_disk.py

@@ -0,0 +1,91 @@
+import struct
+f = open(r'd:\Users\TermiNexus\Desktop\TransPyC\ViperOS\disk.img', 'rb')
+f.seek(0)
+first_sector = f.read(512)
+first_byte = first_sector[0]
+
+if first_byte == 0xEB or first_byte == 0xE9:
+    lba_start = 0
+    bpb = first_sector
+else:
+    ptype = struct.unpack_from('<B', first_sector, 450)[0]
+    lba_start = struct.unpack_from('<I', first_sector, 454)[0]
+    f.seek(lba_start * 512)
+    bpb = f.read(512)
+
+bytes_per_sec = struct.unpack_from('<H', bpb, 11)[0]
+sec_per_clus = struct.unpack_from('<B', bpb, 13)[0]
+rsvd = struct.unpack_from('<H', bpb, 14)[0]
+num_fats = struct.unpack_from('<B', bpb, 16)[0]
+root_clus = struct.unpack_from('<I', bpb, 44)[0]
+fat_size = struct.unpack_from('<I', bpb, 36)[0]
+data_start = rsvd + num_fats * fat_size
+
+print(f'BPS={bytes_per_sec} SPC={sec_per_clus} rsvd={rsvd} NF={num_fats} root_clus={root_clus} fat_size={fat_size} data_start={data_start}')
+
+def read_dir(f, lba_start, data_start, sec_per_clus, bytes_per_sec, cluster, indent="  ", depth=0):
+    if depth > 5:
+        return
+    cluster_sec = data_start + (cluster - 2) * sec_per_clus
+    f.seek((lba_start + cluster_sec) * 512)
+    dir_data = f.read(sec_per_clus * bytes_per_sec)
+    off = 0
+    lfn_parts = {}
+    while off < len(dir_data):
+        first = dir_data[off]
+        if first == 0:
+            break
+        if first == 0xE5:
+            off += 32
+            lfn_parts = {}
+            continue
+        attr = dir_data[off + 11]
+        if attr == 0x0F:  # LFN entry
+            seq = first & 0x3F
+            lfn_chars = []
+            for i in range(5):
+                c = struct.unpack_from('<H', dir_data, off + 2 + i * 2)[0]
+                if c != 0xFFFF and c != 0:
+                    lfn_chars.append(chr(c))
+            for i in range(6):
+                c = struct.unpack_from('<H', dir_data, off + 14 + i * 2)[0]
+                if c != 0xFFFF and c != 0:
+                    lfn_chars.append(chr(c))
+            for i in range(2):
+                c = struct.unpack_from('<H', dir_data, off + 28 + i * 2)[0]
+                if c != 0xFFFF and c != 0:
+                    lfn_chars.append(chr(c))
+            lfn_parts[seq] = ''.join(lfn_chars)
+            off += 32
+            continue
+        if attr == 8:  # Volume label
+            off += 32
+            lfn_parts = {}
+            continue
+        name_bytes = dir_data[off:off + 11]
+        name_str = name_bytes.decode('ascii', errors='replace')
+        nt_case = dir_data[off + 12]
+        clus_hi = struct.unpack_from('<H', dir_data, off + 20)[0]
+        clus_lo = struct.unpack_from('<H', dir_data, off + 26)[0]
+        clus = (clus_hi << 16) | clus_lo
+        fsize = struct.unpack_from('<I', dir_data, off + 28)[0]
+        # Reconstruct LFN
+        lfn = ''
+        if lfn_parts:
+            lfn = ''.join(lfn_parts.get(i, '') for i in sorted(lfn_parts.keys()))
+        case_info = ""
+        if nt_case & 0x08:
+            case_info += " [base_lower]"
+        if nt_case & 0x10:
+            case_info += " [ext_lower]"
+        print(f'{indent}SFN=[{name_str}] NT=0x{nt_case:02X}{case_info} LFN="{lfn}" attr=0x{attr:02X} clus={clus} size={fsize}')
+        if attr & 0x10 and clus >= 2:
+            # Skip . and .. entries
+            sfn_name = name_str.rstrip()
+            if sfn_name != '.' and sfn_name != '..':
+                read_dir(f, lba_start, data_start, sec_per_clus, bytes_per_sec, clus, indent + "  ", depth + 1)
+        off += 32
+        lfn_parts = {}
+
+read_dir(f, lba_start, data_start, sec_per_clus, bytes_per_sec, root_clus)
+f.close()