/* Length of the WIM header on disk. */
#define WIM_HEADER_DISK_SIZE 208
-/* Compressed resources in the WIM are divided into separated compressed chunks
- * of this size. This value is unfortunately not configurable (at least when
- * compatibility with Microsoft's software is desired). */
-#define WIM_CHUNK_SIZE 32768
-
/* Version of the WIM file. There is an older version (used for prerelease
* versions of Windows Vista), but wimlib doesn't support it. The differences
* between the versions are undocumented. */
#define WIM_VERSION 0x10d00
+/* Version number used for a different WIM format, which as of Windows 8 can be
+ * created by passing 0x20000000 in dwFlagsAndAttributes to WIMGAPI's
+ * WIMCreateFile() and specifying either NONE, XPRESS, or LZMS compression.
+ * This format is, however, currently undocumented by Microsoft and is seemingly
+ * incompatible with their own ImageX and Dism programs. wimlib does not yet
+ * support this format. */
+#define WIM_MYSTERY_VERSION 0xe00
+
/* WIM magic characters, translated to a single 64-bit little endian number. */
#define WIM_MAGIC \
cpu_to_le64(((u64)'M' << 0) | \
((u64)'\0' << 48) | \
((u64)'\0' << 54))
+/* On-disk format of the WIM header. */
+struct wim_header_disk {
+
+ /* Magic characters "MSWIM\0\0\0" */
+ le64 magic;
+
+ /* Size of the WIM header, in bytes; WIM_HEADER_DISK_SIZE expected
+ * (currently the only supported value). */
+ u32 hdr_size;
+
+ /* Version of the WIM file; WIM_VERSION expected (currently the only
+ * supported value). */
+ u32 wim_version;
+
+ /* Flags for the WIM file (WIM_HDR_FLAG_*) */
+ u32 wim_flags;
+
+ /* Chunk size for compressed resources in the WIM, or 0 if the WIM is
+ * uncompressed. */
+ u32 chunk_size;
+
+ /* Globally unique identifier for the WIM file. Basically a bunch of
+ * random bytes. */
+ u8 guid[WIM_GID_LEN];
+
+ /* Number of this WIM part in the split WIM file, indexed from 1, or 1
+ * if the WIM is not split. */
+ u16 part_number;
+
+ /* Total number of parts of the split WIM file, or 1 if the WIM is not
+ * split. */
+ u16 total_parts;
+
+ /* Number of images in the WIM. */
+ u32 image_count;
+
+ /* Location and size of the WIM's lookup table. */
+ struct resource_entry_disk lookup_table_res_entry;
+
+ /* Location and size of the WIM's XML data. */
+ struct resource_entry_disk xml_data_res_entry;
+
+ /* Location and size of metadata resource for the bootable image of the
+ * WIM, or all zeroes if no image is bootable. */
+ struct resource_entry_disk boot_metadata_res_entry;
+
+ /* 1-based index of the bootable image of the WIM, or 0 if no image is
+ * bootable. */
+ u32 boot_idx;
+
+ /* Location and size of the WIM's integrity table, or all zeroes if the
+ * WIM has no integrity table.
+ *
+ * Note the integrity_table_res_entry here is 4-byte aligned even though
+ * it would ordinarily be 8-byte aligned--- hence, the _packed_attribute
+ * on the `struct wim_header_disk' is essential. */
+ struct resource_entry_disk integrity_table_res_entry;
+
+ /* Unused bytes. */
+ u8 unused[60];
+} _packed_attribute;
+
+
/* Header at the very beginning of the WIM file. This is the in-memory
* representation and does not include all fields; see `struct wim_header_disk'
* for the on-disk structure. */
/* Bitwise OR of one or more of the WIM_HDR_FLAG_* defined below. */
u32 flags;
+ /* Compressed resource chunk size */
+ u32 chunk_size;
+
/* A unique identifier for the WIM file. */
u8 guid[WIM_GID_LEN];
#define WIM_HDR_FLAG_COMPRESS_RESERVED 0x00010000
/* Resources within the WIM are compressed using "XPRESS" compression, which is
- * a LZ77-based compression algorithm. */
+ * a LZ77-based compression algorithm. */
#define WIM_HDR_FLAG_COMPRESS_XPRESS 0x00020000
/* Resources within the WIM are compressed using "LZX" compression. This is also
* a LZ77-based algorithm. */
#define WIM_HDR_FLAG_COMPRESS_LZX 0x00040000
+/* Starting in Windows 8, WIMGAPI can create WIMs using LZMS compression, and
+ * this flag is set on such WIMs. However, an additional undocumented flag
+ * needs to be provided to WIMCreateFile() to create such WIMs, and the version
+ * number in the header of the resulting WIMs is different (3584). None of this
+ * is actually documented, and wimlib does not yet support this compression
+ * format. */
+#define WIM_HDR_FLAG_COMPRESS_LZMS 0x00080000
+
#endif /* _WIMLIB_HEADER_H */