system compression: force XPRESS4K on files accessed by Windows bootloader
authorEric Biggers <ebiggers3@gmail.com>
Thu, 24 Sep 2015 03:30:34 +0000 (22:30 -0500)
committerEric Biggers <ebiggers3@gmail.com>
Thu, 24 Sep 2015 04:23:24 +0000 (23:23 -0500)
doc/man1/wimlib-imagex-apply.1
src/win32_apply.c

index 5bab69b..b12f8fd 100644 (file)
@@ -400,6 +400,10 @@ Exclusions are handled in the same way as with the \fB--wimboot\fR option.
 That is: if it exists, the [PrepopulateList] section of the file
 \\Windows\\System32\\WimBootCompress.ini in the WIM image will be read, and
 files matching any of the patterns in this section will not be compressed.
+In addition, wimlib has a hardcoded list of files which it knows to, for
+compatibility with the Windows bootloader which only supports
+XPRESS4K-compressed files, always extract using either XPRESS4K or no
+compression.
 .SH NOTES
 \fIData integrity\fR:  WIM files include SHA1 message digests for file data.
 \fBwimlib-imagex apply\fR calculates the SHA1 message digest of every file
index ce62d6a..5bc1e51 100644 (file)
@@ -151,6 +151,11 @@ struct win32_apply_ctx {
        /* Number of files on which we couldn't set System Compression.  */
        unsigned long num_system_compression_failures;
 
+       /* The number of files on which we used XPRESS4K System Compression
+        * rather than a stronger variant, to be compatible with the Windows
+        * bootloader.  */
+       unsigned long num_xpress4k_forced_files;
+
        /* Have we tried to enable short name support on the target volume yet?
         */
        bool tried_to_enable_short_names;
@@ -2264,6 +2269,22 @@ get_system_compression_format(int extract_flags)
        return FILE_PROVIDER_COMPRESSION_FORMAT_LZX;
 }
 
+
+static const wchar_t *
+get_system_compression_format_string(int format)
+{
+       switch (format) {
+       case FILE_PROVIDER_COMPRESSION_FORMAT_XPRESS4K:
+               return L"XPRESS4K";
+       case FILE_PROVIDER_COMPRESSION_FORMAT_XPRESS8K:
+               return L"XPRESS8K";
+       case FILE_PROVIDER_COMPRESSION_FORMAT_XPRESS16K:
+               return L"XPRESS16K";
+       default:
+               return L"LZX";
+       }
+}
+
 static NTSTATUS
 set_system_compression(HANDLE h, int format)
 {
@@ -2299,6 +2320,43 @@ set_system_compression(HANDLE h, int format)
        return status;
 }
 
+/* Hard-coded list of files which the Windows bootloader needs to access before
+ * the WOF driver has been loaded.  Since the Windows bootloader only supports
+ * the XPRESS4K variant of System Compression, such files should not be
+ * compressed using other variants.  */
+static wchar_t *xpress4k_only_pattern_strings[] = {
+       L"*winload.*",
+       L"*winresume.*",
+       L"\\Windows\\AppPatch\\drvmain.sdb",
+       L"\\Windows\\Fonts\\vgaoem.fon",
+       L"\\Windows\\Fonts\\vgasys.fon",
+       L"\\Windows\\INF\\errata.inf",
+       L"\\Windows\\System32\\config\\*",
+       L"\\Windows\\System32\\ntkrnlpa.exe",
+       L"\\Windows\\System32\\ntoskrnl.exe",
+       L"\\Windows\\System32\\bootvid.dll",
+       L"\\Windows\\System32\\ci.dll",
+       L"\\Windows\\System32\\hal*.dll",
+       L"\\Windows\\System32\\mcupdate_AuthenticAMD.dll",
+       L"\\Windows\\System32\\mcupdate_GenuineIntel.dll",
+       L"\\Windows\\System32\\pshed.dll",
+       L"\\Windows\\System32\\apisetschema.dll",
+       L"\\Windows\\System32\\api-ms-win*.dll",
+       L"\\Windows\\System32\\ext-ms-win*.dll",
+       L"\\Windows\\System32\\KernelBase.dll",
+       L"\\Windows\\System32\\drivers\\*.sys",
+       L"\\Windows\\System32\\*.nls",
+       L"\\Windows\\System32\\kbd*.dll",
+       L"\\Windows\\System32\\kd*.dll",
+       L"\\Windows\\System32\\clfs.sys",
+       L"\\Windows\\System32\\CodeIntegrity\\driver.stl",
+};
+
+static const struct string_set xpress4k_only_patterns = {
+       .strings = xpress4k_only_pattern_strings,
+       .num_strings = ARRAY_LEN(xpress4k_only_pattern_strings),
+};
+
 static NTSTATUS
 set_system_compression_on_inode(struct wim_inode *inode, int format,
                                struct win32_apply_ctx *ctx)
@@ -2307,6 +2365,41 @@ set_system_compression_on_inode(struct wim_inode *inode, int format,
        NTSTATUS status;
        HANDLE h;
 
+       /* If needed, force the XPRESS4K format for this file.  */
+       if (format != FILE_PROVIDER_COMPRESSION_FORMAT_XPRESS4K) {
+               /* We need to check the patterns against every name of the
+                * inode, in case any of them match.  */
+               struct wim_dentry *dentry;
+               inode_for_each_extraction_alias(dentry, inode) {
+                       bool incompatible;
+
+                       if (calculate_dentry_full_path(dentry)) {
+                               ERROR("Unable to compute file path!");
+                               return STATUS_NO_MEMORY;
+                       }
+
+                       incompatible = match_pattern_list(dentry->d_full_path,
+                                                         &xpress4k_only_patterns);
+                       FREE(dentry->d_full_path);
+                       dentry->d_full_path = NULL;
+
+                       if (incompatible) {
+                               if (ctx->num_xpress4k_forced_files++ == 0) {
+                                       WARNING("For compatibility with the "
+                                               "Windows bootloader, some "
+                                               "files are being\n"
+                                               "          compacted "
+                                               "using the XPRESS4K format "
+                                               "instead of the %"TS" format\n"
+                                               "          you requested.",
+                                               get_system_compression_format_string(format));
+                               }
+                               format = FILE_PROVIDER_COMPRESSION_FORMAT_XPRESS4K;
+                               break;
+                       }
+               }
+       }
+
        /* Open the extracted file.  */
        status = create_file(&h, GENERIC_READ | GENERIC_WRITE, NULL,
                             0, FILE_OPEN, 0,