#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
/* Compressed resources in the WIM are divided into separated compressed chunks
- * of this size. */
+ * 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, but we don't support it
- * yet. The differences between the versions are undocumented. */
+/* 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
-/* 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];
+/* 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; WIM_VERSION expected (currently the only
+ * supported value). */
+ u32 wim_version;
+
+ /* Flags for the WIM file (WIM_HDR_FLAG_*) */
+ u32 wim_flags;
+
+ /* Uncompressed chunk size of resources in the WIM. 0 if the WIM is
+ * uncompressed. If compressed, WIM_CHUNK_SIZE is expected (currently
+ * the only supported value). */
+ 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;
- /* size of WIM header in bytes. */
- //u32 hdr_size;
+ /* Location and size of the WIM's lookup table. */
+ struct resource_entry_disk lookup_table_res_entry;
- /* 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;
+ /* 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. */
+struct wim_header {
+
+ /* Magic characters: either WIM_MAGIC or PWM_MAGIC. */
+ le64 magic;
/* 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;
-
/* A unique identifier for the WIM file. */
u8 guid[WIM_GID_LEN];
/* 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];
};
/* 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
projects / wimlib / blobdiff