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MK_ROMFS - Make a ROMFS image
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This program creates a ROMFS image that can be read by eCos.

mk_romfs - Create an eCos ROMFS disk image from the files
                      contained under a specified directory

Usage: ../support/mk_romfs [options] <fs_root> <fs_file>
 fs_root    is the directory containing the files to package into the ROMFS image
 fs_file    is the name of the ROMFS image file to create
          Options include:
 -v / -q    increase / decrease verbosity
 -n         do everything EXCEPT creating the output file
 -b         write a big-endian image (default is little endian)
 -l         collapse hard links to a single node

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How to use.
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For example, suppose you wish to access the following directories and files:
        /
        /etc    passwd, group
        /dev
        /mnt
        /tmp    (for a RAMFS)
        /var    (for a RAMFS)

1. Create the required directories and files under a suitable root, eg. under
   ~/rom:
        $ mkdir ~/rom
        $ cd ~/rom
        $ mkdir etc dev mnt tmp var
        $ cp /etc/passwd /etc/group etc/
                ( remembering to edit these files....;-)

2. Make the romfs image in a suitable place, eg /tftpboot for direct upload to
   the RedBoot monitor.
        $ mk_romfs -v . /tftpboot/romfs.img
        mk_romfs: Verbosity 2 little endian
        Phase 1  - Build file list
        Phase 2  - Calculate space allocation
        Phase 2a -     * Directories
        Phase 2b -     * Regular files
        Phase 2c -     * Executable files
        Phase 3  - Construct ROMFS image file (3 kb)
        Phase 3a -     * Node table
        Phase 3b -     * Data blocks
        /tftpboot/romfs.img completed

3. Connect to your target RedBoot monitor, and load the romfs image. You will
   need to determine a suitable place in RAM to load the image into.
        $ telnet xxx.xxx.xxx.xxx 1000
        Trying xxx.xxx.xxx.xxx...
        Connected to xxx.xxx.xxx.xxx.
        Escape character is '^]'.
        RedBoot> load romfs.img -r -v -b 0x1000000
        Raw file loaded 0x01000000-0x0100093e
        RedBoot>

4. Determine where to load the romfs image in the ROM. See what's there...
        RedBoot> fis list
        Name              FLASH addr   Mem addr    Length    Entry point
        RedBoot           0x50000000   0x50000000  0x020000  0x00000000
        RedBoot[backup]   0x50020000   0x50020000  0x020000  0x00000000
        RedBoot config    0x503C0000   0x503C0000  0x020000  0x00000000
        FIS directory     0x503E0000   0x503E0000  0x020000  0x00000000
        RedBoot> fis free
          0x50040000 .. 0x503C0000
        RedBoot>
   We can see that a suitable place would be 0x50040000.
   Alternatively, you can let RedBoot determine the address itself...

5. Copy the image from RAM to ROM...
        RedBoot> fis create -b 0x1000000 -l 0x940 RomFs
        ... Erase from 0x50040000-0x50040940: .
        ... Program from 0x01000000-0x01000940 at 0x50040000: .
        ... Erase from 0x503e0000-0x50400000: .
        ... Program from 0x01fd0000-0x01ff0000 at 0x503e0000: .
        RedBoot> fis list
        Name              FLASH addr   Mem addr    Length    Entry point
        RedBoot           0x50000000   0x50000000  0x020000  0x00000000
        RedBoot[backup]   0x50020000   0x50020000  0x020000  0x00000000
        RedBoot config    0x503C0000   0x503C0000  0x020000  0x00000000
        FIS directory     0x503E0000   0x503E0000  0x020000  0x00000000
        RomFs             0x50040000   0x01000000  0x000940  0x00000000
        RedBoot>

6. MAKE A NOTE OF THE ADDRESS IN FLASH THAT THE IMAGE IS LOADED AT.

   This address can then be used in your program in order to mount the
   filesystem.

   For example, to automatically mount the new romfs created above at
   /rom, you can use the following macro in your application:

       MTAB_ENTRY( romfs_mte1,
                   "/rom",
                   "romfs",
                   "",
                   (CYG_ADDRWORD) 0x50040000 );

   See the File I/O package documentation in the eCos Reference Manual
   ("Writing a New Filesystem") for more information about the MTAB_ENTRY
   macro.

   Alternatively, the filesystem can be dynamically mounted with a call
   to mount() such as the following:

     err = mount( "0x50040000", "/rom", "romfs" );