X-Git-Url: https://wimlib.net/git/?p=wimlib;a=blobdiff_plain;f=include%2Fwimlib%2Fheader.h;h=6c522fa2622ffd14299e90de0a3c72c9b62ae87c;hp=151d6c78b4dd1db9a08d97b4ba6423f1cfcc1495;hb=de567a8c5dcd0910a8c762d75bf11b9c9683396c;hpb=e8c3ca2d1d0cac3d64985b45a9f654d2029a7518 diff --git a/include/wimlib/header.h b/include/wimlib/header.h index 151d6c78..6c522fa2 100644 --- a/include/wimlib/header.h +++ b/include/wimlib/header.h @@ -1,126 +1,197 @@ #ifndef _WIMLIB_HEADER_H #define _WIMLIB_HEADER_H +#include + #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. Streams are always compressed independently. */ +#define WIM_VERSION_DEFAULT 0x10d00 + +/* Version number used for WIMs that allow multiple streams 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. (However wimlib will accept + * any value here 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 lookup table. */ + struct wim_reshdr_disk lookup_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 lookup_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 streams included in the WIM's lookup 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 streams included in the WIM's lookup 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 */