#include "wimlib/resource.h"
#include "wimlib/types.h"
+#include "wimlib/endianness.h"
-#define WIM_MAGIC_LEN 8
+/* Length of "Globally Unique ID" field in WIM header. */
#define WIM_GID_LEN 16
-#define WIM_UNUSED_LEN 60
-/* Length of the WIM header on disk. */
-#define WIM_HEADER_DISK_SIZE (148 + WIM_UNUSED_LEN)
+/* Length of the WIM header on disk. */
+#define WIM_HEADER_DISK_SIZE 208
+
+/* 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_DEFAULT 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 currently undocumented by Microsoft and is seemingly
+ * incompatible with their own ImageX and Dism programs; however, it seems to be
+ * used for Windows 8 updates. The format appears to feature a new flag (0x10)
+ * in resource entries, which I've named WIM_RESHDR_FLAG_CONCAT. */
+#define WIM_VERSION_STREAM_CONCAT 0xe00
+
+/* WIM magic characters, translated to a single 64-bit little endian number. */
+#define WIM_MAGIC \
+ cpu_to_le64(((u64)'M' << 0) | \
+ ((u64)'S' << 8) | \
+ ((u64)'W' << 16) | \
+ ((u64)'I' << 24) | \
+ ((u64)'M' << 32) | \
+ ((u64)'\0' << 40) | \
+ ((u64)'\0' << 48) | \
+ ((u64)'\0' << 54))
+
+/* wimlib pipable WIM magic characters, translated to a single 64-bit little
+ * endian number. */
+#define PWM_MAGIC \
+ cpu_to_le64(((u64)'W' << 0) | \
+ ((u64)'L' << 8) | \
+ ((u64)'P' << 16) | \
+ ((u64)'W' << 24) | \
+ ((u64)'M' << 32) | \
+ ((u64)'\0' << 40) | \
+ ((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
+ * TODO */
+ 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 wim_reshdr_disk lookup_table_reshdr;
-/* Compressed resources in the WIM are divided into separated compressed chunks
- * of this size. */
-#define WIM_CHUNK_SIZE 32768
+ /* Location and size of the WIM's XML data. */
+ struct wim_reshdr_disk xml_data_reshdr;
-/* Version of the WIM file. There is an older version, but we don't support it
- * yet. The differences between the versions are undocumented. */
-#define WIM_VERSION 0x10d00
+ /* Location and size of metadata resource for the bootable image of the
+ * WIM, or all zeroes if no image is bootable. */
+ struct wim_reshdr_disk boot_metadata_reshdr;
-/* Header at the very beginning of the WIM file. */
+ /* 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_reshdr 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 wim_reshdr_disk integrity_table_reshdr;
+
+ /* 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. */
struct wim_header {
- /* Identifies the file as WIM file. Must be exactly
- * {'M', 'S', 'W', 'I', 'M', 0, 0, 0} */
- //u8 magic[WIM_MAGIC_LEN];
- /* size of WIM header in bytes. */
- //u32 hdr_size;
+ /* Magic characters: either WIM_MAGIC or PWM_MAGIC. */
+ le64 magic;
- /* Version of the WIM file. Microsoft provides no documentation about
- * exactly what this field affects about the file format, other than the
- * fact that more recent versions have a higher value. */
- //u32 version;
+ /* Version of the WIM file */
+ u32 wim_version;
/* Bitwise OR of one or more of the WIM_HDR_FLAG_* defined below. */
u32 flags;
- /* The size of the pieces that the uncompressed files were split up into
- * when they were compressed. This should be the same as
- * WIM_CHUNK_SIZE. Microsoft incorrectly documents this as "the size of
- * the compressed .wim file in bytes".*/
- //u32 chunk_size;
+ /* Compressed resource chunk size */
+ u32 chunk_size;
/* A unique identifier for the WIM file. */
u8 guid[WIM_GID_LEN];
u32 image_count;
/* Location, size, and flags of the lookup table of the WIM. */
- struct resource_entry lookup_table_res_entry;
+ struct wim_reshdr lookup_table_reshdr;
/* Location, size, and flags for the XML data of the WIM. */
- struct resource_entry xml_res_entry;
+ struct wim_reshdr xml_data_reshdr;
/* Location, size, and flags for the boot metadata. This means the
* metadata resource for the image specified by boot_idx below. Should
* be zeroed out if boot_idx is 0. */
- struct resource_entry boot_metadata_res_entry;
+ struct wim_reshdr boot_metadata_reshdr;
/* The index of the bootable image in the WIM file. If 0, there are no
* bootable images available. */
/* The location of the optional integrity table used to verify the
* integrity WIM. Zeroed out if there is no integrity table.*/
- struct resource_entry integrity;
-
- /* Reserved for future disuse */
- //u8 unused[WIM_UNUSED_LEN];
+ struct wim_reshdr integrity_table_reshdr;
};
/* Flags for the `flags' field of the struct wim_header: */
/* Files and metadata in the WIM are compressed. */
#define WIM_HDR_FLAG_COMPRESSION 0x00000002
-/* WIM is read-only (wimlib ignores this because it's pretty much pointless) */
+/* WIM is read-only, so modifications should not be allowed even if the WIM is
+ * writable at the filesystem level. */
#define WIM_HDR_FLAG_READONLY 0x00000004
/* Resource data specified by images in this WIM may be contained in a different
* metadata resources for a split WIM should be in the first part. */
#define WIM_HDR_FLAG_METADATA_ONLY 0x00000020
-/* Lock field to prevent multiple writers from writing the WIM concurrently.
- * wimlib ignores this flag as it uses flock() to acquire a real lock on the
- * file (if supported by the underlying filesystem). */
+/* The WIM is currently being written or appended to. */
#define WIM_HDR_FLAG_WRITE_IN_PROGRESS 0x00000040
/* Reparse point fixup flag. See docs for --rpfix and --norpfix in imagex, or
#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 */
git://wimlib.net / wimlib / blobdiff