Merge branch with pipable WIM support

[wimlib] / include / wimlib / header.h

diff --git a/include/wimlib/header.h b/include/wimlib/header.h
index 0702b45bfa9b9c30af662ee0e074cc46033b510e..238b6b22122858bd3ba8fe2870484b6062089c5e 100644 (file)
--- a/include/wimlib/header.h
+++ b/include/wimlib/header.h
@@ -3,24 +3,54 @@
 
 #include "wimlib/resource.h"
 #include "wimlib/types.h"
+#include "wimlib/endianness.h"
 
+/* Length of "Globally Unique ID" field in WIM header.  */
 #define WIM_GID_LEN    16
 
-/* Length of the WIM header on disk. */
+/* 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, but wimlib doesn't
+ * support it.  The differences between the versions are undocumented.  */
 #define WIM_VERSION 0x10d00
 
+/* 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))
+
 /* 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. */
+ * 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;