初始化奇妙小屏幕控制器项目

2026-09-08 22:56:52 +08:00
commit 8d368de3b5
491 changed files with 67678 additions and 0 deletions
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+from __future__ import annotations
+
+from pathlib import Path
+import struct
+
+
+SECTOR_BYTES = 512
+PARTITION_LBA = 1
+PARTITION_SECTORS = 8192
+RESERVED_SECTORS = 1
+FAT_COUNT = 2
+FAT_SECTORS = 32
+ROOT_ENTRIES = 512
+ROOT_SECTORS = ROOT_ENTRIES * 32 // SECTOR_BYTES
+DATA_RELATIVE_SECTOR = RESERVED_SECTORS + FAT_COUNT * FAT_SECTORS + ROOT_SECTORS
+
+
+def build_fixture(path: Path, config_file: bytes) -> Path:
+    if len(config_file) != 64 * 1024:
+        raise ValueError("配置文件必须为 64 KiB")
+    image = bytearray((PARTITION_LBA + PARTITION_SECTORS) * SECTOR_BYTES)
+    image[510:512] = b"\x55\xaa"
+    partition_entry = 446
+    image[partition_entry + 4] = 0x06
+    struct.pack_into("<II", image, partition_entry + 8, PARTITION_LBA, PARTITION_SECTORS)
+
+    boot = PARTITION_LBA * SECTOR_BYTES
+    image[boot : boot + 3] = b"\xeb\x3c\x90"
+    image[boot + 3 : boot + 11] = b"MSDOS5.0"
+    struct.pack_into("<H", image, boot + 11, SECTOR_BYTES)
+    image[boot + 13] = 1
+    struct.pack_into("<H", image, boot + 14, RESERVED_SECTORS)
+    image[boot + 16] = FAT_COUNT
+    struct.pack_into("<H", image, boot + 17, ROOT_ENTRIES)
+    struct.pack_into("<H", image, boot + 19, PARTITION_SECTORS)
+    image[boot + 21] = 0xF8
+    struct.pack_into("<H", image, boot + 22, FAT_SECTORS)
+    image[boot + 510 : boot + 512] = b"\x55\xaa"
+
+    fat = bytearray(FAT_SECTORS * SECTOR_BYTES)
+    struct.pack_into("<HH", fat, 0, 0xFFF8, 0xFFFF)
+    clusters = len(config_file) // SECTOR_BYTES
+    for index in range(clusters):
+        cluster = 2 + index
+        struct.pack_into("<H", fat, cluster * 2, 0xFFFF if index == clusters - 1 else cluster + 1)
+    first_fat = boot + RESERVED_SECTORS * SECTOR_BYTES
+    image[first_fat : first_fat + len(fat)] = fat
+    image[first_fat + len(fat) : first_fat + 2 * len(fat)] = fat
+
+    root = boot + (RESERVED_SECTORS + FAT_COUNT * FAT_SECTORS) * SECTOR_BYTES
+    image[root : root + 11] = b"MSCCFG  BIN"
+    image[root + 11] = 0x20
+    struct.pack_into("<H", image, root + 26, 2)
+    struct.pack_into("<I", image, root + 28, len(config_file))
+    data = boot + DATA_RELATIVE_SECTOR * SECTOR_BYTES
+    image[data : data + len(config_file)] = config_file
+    path.write_bytes(image)
+    return path
+
+
+def first_fat_offset() -> int:
+    return (PARTITION_LBA + RESERVED_SECTORS) * SECTOR_BYTES
+