Subversion Repositories openrisc_2011-10-31

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.
   The ROMFS option 'CYGNUM_FS_ROM_BASE_ADDRESS' needs to be set to this
   value in order to access the filesystem.