1 files changed, 43 insertions, 0 deletions
diff --git a/doc/genisoimage/README.macosx b/doc/genisoimage/README.macosx
new file mode 100644
index 0000000..e082bfc
--- /dev/null
+++ b/doc/genisoimage/README.macosx
@@ -0,0 +1,43 @@
+Notes on using the --osx-hfs option when running genisoimage on MacOS X
+
+genisoimage does not use any of the MacOS APIs to access files - it uses
+standard (POSIX style) library calls. Under normal circumstances, all
+genisoimage will 'see' is the data fork of files on an HFS (or HFS+) file system.
+
+However, Apple have provided a way for POSIX style applications to 
+access the resource fork - using the following syntax:
+
+If a file exists on an HFS volume with the name 'foo', then the resource fork
+can be accessed using the file name 'foo/rsrc' or foo/..namedfork/rsrc'
+(the data fork can also be accessed using 'foo/..namedfork/data').
+
+These 'pseudo' file names are not normally visible in a directory - unless
+you access them directly (e.g. 'ls -l */rsrc etc).
+
+To access the finder information, Apple have provided an undocumented library
+function called getattrlist(). Fortunately there are example of its usage
+in the Darwin (MacOS kernel) source code.
+
+
+Although MacOS X can use HFS(+) as its file system, Apple have decided to
+move away from using HFS to store finder info and resource data - for 
+example, the TYPE of a file may be based on its file name extension and the
+TYPE field in the finder info empty.
+
+genisoimage knows nothing about these file name extension mappings, so if the
+--osx-hfs option is used and the source files are on MacOS X HFS(+) volumes,
+by the fact that they are HFS files, they will get identified as 'MacOS X HFS'
+and the resulting file on the output CD image will have empty TYPE and CREATOR
+fields.
+
+Therefore, if the input finderinfo is blank and the the resource fork is
+empty, genisoimage will assume the input file is not a 'real' HFS file - which
+means the TYPE and CREATOR may then be set using the file's magic number or
+genisoimage' file name extension mapping.
+
+The only real benefit of using the --osx-hfs option is when the source files
+are on an OS9 or earlier HFS or HFS+ volume e.g. an existing HFS CD.
+
+James Pearson 3-Jul-2002
+Edited for program name change by Eduard Bloch, 2006
+