#ifndef _WIMLIB_HEADER_H
#define _WIMLIB_HEADER_H
+#include <limits.h>
+
#include "wimlib/resource.h"
#include "wimlib/types.h"
-#define WIM_MAGIC_LEN 8
-#define WIM_GID_LEN 16
-#define WIM_UNUSED_LEN 60
+/* Length of "Globally Unique ID" field in WIM header. */
+#define WIM_GUID_LEN 16
+
+/* Length of the WIM header on disk. wimlib currently requires that the header
+ * be exactly this size. */
+#define WIM_HEADER_DISK_SIZE 208
+
+/* Default WIM version number. Blobs are always compressed independently. */
+#define WIM_VERSION_DEFAULT 0x10d00
+
+/* Version number used for WIMs that allow multiple blobs combined into one
+ * resource ("solid resources", marked by WIM_RESHDR_FLAG_SOLID) and also a new
+ * compression format (LZMS). This version is new as of Windows 8 WIMGAPI.
+ * Although it is used by Windows 8 web downloader, it is not yet documented by
+ * Microsoft. */
+#define WIM_VERSION_SOLID 0xe00
+
+/* Note: there is another WIM version from Vista pre-releases, but it is not
+ * supported by wimlib. */
+
+/* WIM magic characters, translated to a single 64-bit number. */
+#define WIM_MAGIC \
+ (((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 number.
+ * */
+#define PWM_MAGIC \
+ (((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 {
+
+ /* +0x00: Magic characters WIM_MAGIC or PWM_MAGIC. */
+ le64 magic;
+
+ /* +0x08: Size of the WIM header, in bytes; WIM_HEADER_DISK_SIZE
+ * expected (currently the only supported value). */
+ u32 hdr_size;
+
+ /* +0x0c: Version of the WIM file. Recognized values are the
+ * WIM_VERSION_* constants from above. */
+ u32 wim_version;
+
+ /* +0x10: Flags for the WIM file (WIM_HDR_FLAG_*). */
+ u32 wim_flags;
+
+ /* +0x14: Uncompressed chunk size for non-solid compressed resources in
+ * the WIM or 0 if the WIM is uncompressed. */
+ u32 chunk_size;
+
+ /* +0x18: Globally unique identifier for the WIM file. Basically a
+ * bunch of random bytes. */
+ u8 guid[WIM_GUID_LEN];
+
+ /* +0x28: Number of this WIM part in the split WIM file, indexed from 1,
+ * or 1 if the WIM is not split. */
+ u16 part_number;
-/* Length of the WIM header on disk. */
-#define WIM_HEADER_DISK_SIZE (148 + WIM_UNUSED_LEN)
+ /* +0x2a: Total number of parts of the split WIM file, or 1 if the WIM
+ * is not split. */
+ u16 total_parts;
-/* Compressed resources in the WIM are divided into separated compressed chunks
- * of this size. */
-#define WIM_CHUNK_SIZE 32768
+ /* +0x2c: Number of images in the WIM. WIMGAPI requires that this be at
+ * least 1. wimlib allows 0. */
+ u32 image_count;
-/* 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
+ /* +0x30: Location and size of the WIM's blob table. */
+ struct wim_reshdr_disk blob_table_reshdr;
-/* Header at the very beginning of the WIM file. */
-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];
+ /* +0x48: Location and size of the WIM's XML data. */
+ struct wim_reshdr_disk xml_data_reshdr;
- /* size of WIM header in bytes. */
- //u32 hdr_size;
+ /* +0x60: 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;
- /* 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;
+ /* +0x78: 1-based index of the bootable image of the WIM, or 0 if no
+ * image is bootable. */
+ u32 boot_idx;
- /* Bitwise OR of one or more of the WIM_HDR_FLAG_* defined below. */
- u32 flags;
+ /* +0x7c: 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
+ * this structure is essential. */
+ struct wim_reshdr_disk integrity_table_reshdr;
- /* 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;
+ /* +0x94: Unused bytes. */
+ u8 unused[60];
- /* A unique identifier for the WIM file. */
- u8 guid[WIM_GID_LEN];
+ /* +0xd0 (208) */
+} _packed_attribute;
- /* Part number of the WIM file in a spanned set. */
- u16 part_number;
+#define MAX_IMAGES (((INT_MAX < INT32_MAX) ? INT_MAX : INT32_MAX) - 1)
- /* Total number of parts in a spanned set. */
+/* In-memory representation of a WIM header. See `struct wim_header_disk' for
+ * field descriptions. */
+struct wim_header {
+ u64 magic;
+ u32 wim_version;
+ u32 flags;
+ u32 chunk_size;
+ u8 guid[WIM_GUID_LEN];
+ u16 part_number;
u16 total_parts;
-
- /* Number of images in the WIM file. */
u32 image_count;
-
- /* Location, size, and flags of the lookup table of the WIM. */
- struct resource_entry lookup_table_res_entry;
-
- /* Location, size, and flags for the XML data of the WIM. */
- struct resource_entry xml_res_entry;
-
- /* 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;
-
- /* The index of the bootable image in the WIM file. If 0, there are no
- * bootable images available. */
+ struct wim_reshdr blob_table_reshdr;
+ struct wim_reshdr xml_data_reshdr;
+ struct wim_reshdr boot_metadata_reshdr;
u32 boot_idx;
-
- /* 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: */
+/* WIM header flags ('wim_flags' field of 'struct wim_header_disk'): */
-/* Reserved for future use */
+/* Reserved flag. */
#define WIM_HDR_FLAG_RESERVED 0x00000001
-/* Files and metadata in the WIM are compressed. */
+/* The WIM may contain compressed resources --- specifically, resources with
+ * WIM_RESHDR_FLAG_COMPRESSED set in their headers. Exactly one of the more
+ * specific WIM_HDR_FLAG_COMPRESSION_* flags must be set to specify the
+ * compression format used. */
#define WIM_HDR_FLAG_COMPRESSION 0x00000002
-/* WIM is read-only (wimlib ignores this because it's pretty much pointless) */
+/* The 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
- * WIM. Or in other words, this WIM is part of a split WIM. */
+/* The WIM is part of a split WIM. */
#define WIM_HDR_FLAG_SPANNED 0x00000008
-/* The WIM contains resources only; no filesystem metadata. wimlib ignores this
- * flag, as it looks for resources in all the WIMs anyway. */
+/* All blobs included in the WIM's blob table are non-metadata (do not have
+ * WIM_RESHDR_FLAG_METADATA set). wimlib ignores this flag and clears it on new
+ * WIM files it writes. */
#define WIM_HDR_FLAG_RESOURCE_ONLY 0x00000010
-/* The WIM contains metadata only. wimlib ignores this flag. Note that all the
- * metadata resources for a split WIM should be in the first part. */
+/* All blobs included in the WIM's blob table are metadata (have
+ * WIM_RESHDR_FLAG_METADATA set). wimlib ignores this flag and clears it on new
+ * WIM files it writes. */
#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
- * WIMLIB_ADD_FLAG_{RPFIX,NORPFIX} in wimlib.h. Note that
- * WIM_HDR_FLAG_RP_FIX is a header flag and just sets the default behavior for
- * the WIM; it can still be overridder on a per-image basis. But there is no
- * flag to set the default behavior for a specific image. */
+/* Reparse point fixup flag. See docs for the --rpfix and --norpfix options to
+ * 'wimlib-imagex capture', or the WIMLIB_ADD_FLAG_{RPFIX,NORPFIX} flags in
+ * wimlib.h. Note that WIM_HDR_FLAG_RP_FIX is a header flag and just sets the
+ * default behavior for the WIM; it can still be programatically overridden on a
+ * per-image basis. But there is no flag in the file format to set the default
+ * behavior for a specific image. */
#define WIM_HDR_FLAG_RP_FIX 0x00000080
-/* Unused, reserved flag for another compression type */
+/* Unused, reserved flag for another compression type. */
#define WIM_HDR_FLAG_COMPRESS_RESERVED 0x00010000
-/* Resources within the WIM are compressed using "XPRESS" compression, which is
- * a LZ77-based compression algorithm. */
+/* Resources in the WIM with WIM_RESHDR_FLAG_COMPRESSED set in their headers are
+ * compressed with XPRESS compression. */
#define WIM_HDR_FLAG_COMPRESS_XPRESS 0x00020000
-/* Resources within the WIM are compressed using "LZX" compression. This is also
- * a LZ77-based algorithm. */
+/* Resources in the WIM with WIM_RESHDR_FLAG_COMPRESSED set in their headers are
+ * compressed with LZX compression. */
#define WIM_HDR_FLAG_COMPRESS_LZX 0x00040000
+/* Resources in the WIM with WIM_RESHDR_FLAG_COMPRESSED set in their headers are
+ * compressed with LZMS compression. Note: this flag is only valid if the WIM
+ * version is WIM_VERSION_SOLID. Also, this flag is only supported in wimlib
+ * v1.6.0 and later and WIMGAPI Windows 8 and later. */
+#define WIM_HDR_FLAG_COMPRESS_LZMS 0x00080000
+
+/* XPRESS, with small chunk size??? */
+#define WIM_HDR_FLAG_COMPRESS_XPRESS_2 0x00200000
+
#endif /* _WIMLIB_HEADER_H */