IMFS question

[Joel Sherrill]

Glen M Cornell wrote:
> 
> Chris Johns wrote:
> 
> > Glen M Cornell wrote:
> >
> >> Is there a utility or procedure to convert a directory of files into
> >> an in-memory file system?
> >>
> >
> > What I have done with a m68k target is make a tar file (not
> > compressed) of the files to serve. Then run:
> >
> >
> >   m68k-rtems-ld -r -o pages-tar.o -b binary pages.tar
> >
> very cool.  I've been converting files to c code, then compiling - which
> could take a long time.  I use the following bourne shell function:

This is a good alternative and I have used it for other static
data in the past.


> convert_file() {
>   FILE=$1
>   NAME=$2
> 
>   cat - <<EOF
> /*
>  * File data for ${FILE}
>  */
> static unsigned char file_${NAME}[] = {
> EOF
> 
>   # Because a file may not be a text file, we can't place the
>   # code in a string of bytes as characters.  Instead, we will
>   # use od to print out the hexadecimal values of each character
>   # as an element in an array of unsigned bytes:
>   cat $FILE | /bin/od -v -t xC | cut -c9- |
>     sed -e '/^[     ]*$/d' -e 's/\([0-9a-f][0-9a-f]\)/0x\1,/g'
> 
>   echo "};"
>   echo ""
> }
> 
> to essentially do the same thing as the ld trick.
> 
> However, what I'm looking to do is create the file system at compile
> time to avoid any startup-time penalties associated with creating the
> file system and creating/copying the directories and files.

It doesn't copy the files, it leaves them in the tar image until
modified.  If they are read-only, they will never leave the
static image.

-- 
Joel Sherrill, Ph.D.             Director of Research & Development
joel at OARcorp.com                 On-Line Applications Research
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