Tomato is an Open source code. Anyone can download it from the internet, customize it and run it on their own hardware. This tomato distribution can be run on various architectures. Developer can configure it according to his/her needs. Usually application specific codes are not changed frequently until and unless the developer wants to add new features or remove some features from it.

Following are the main directories in the distribution.

src/linux/linux:
        Total linux distribution. Kernel version is 2.4.20.
src/cfe:
        Source code of the bootloader CFE. CFE bootloader is running onto the WGR614L board also.

src/router:
        Total application specific code are there like busybox, network related tools etc.
src/image:
        After successful compilation firmware is put into this directory.
src/prebuilt:
        Prebuilt modules are present there like PPPoE, PPTP etc.
src/rts
        Source of utilities for computing various CRCs.
src/mksquashfs
        Source of squashfs and lzma present.

Support for WGR614L has been added into tomato source code so that tomato firmware can run onto that board also. Those are

src/linux/linux/arch/mips/brcm-boards:
        It actually contains WGR614L board specific code. Interrupt controller, serial driver, memory layout etc. We can call it as the BSP (Board Support Package) code of the WGR614L board.

linux/linux/drivers/mtd/maps/bcm947xx-flash.c:
linux/linux/drivers/mtd/devices/sflash.c:
        Source code of the flash driver.

src/et:
        Source code of Ethernet driver for WGR614L.

src/wl:
        Object code of Wireless driver for WGR614L.

src/shared:
src/include:
        Common code and header files used by all of the above.

Read More In: WGR614L Open Source Router