This is firmware pack/unpack utility for jboot-based routers.
You also need squashfs and unsquashfs (you can get it from firmware-mod-kit) of corresponding versions.

OpenSource replacement for binboy from SDK found in:
D-Link DIR-510L
D-Link DWR-116
D-Link DWR-521 Rev.B
D-Link DWR-921
Zyxel LTE 3301
Zyxel LTE 3311
Lava Telecom LR-25G001

Now only static kernel/bootloader offsets supported (see in code)

./openbinboy [-c] [-e] < -i input.bin | -x input.bin >

  -c      Use old style jboot CRC for some calculations (DWR-921 and others), if you see CRC mismatches, try this option
  -e      Use big endian for all calculations (all except Zyxel LTE3301-Q222)
  -i      Print headers and do sanity check on whole firmware or single container
  -x      Extract files from whole firmware to bootloader.bin + kernel.bin + rootfs.bin + branding.bin
  -t      Use specified unixtime for inclusion to image header
  -h      Add branding header to input file { [-c] [-e] [-t unixtime ] -i input.bin -o output.bin }
  -n      Assemble whole firmware { -n [-c] [-e] [-t unixtime ] -k kernel.bin -r rootfs.bin [-u bootloader.bin] [-b branding.bin ] -o output.bin }
  -L      Kernel load address for firmware creation (default 0x80000000)
  -E      Kernel entry point for firmware creation (default 0x80000000)
  -I      Device ID (text) for build firmware (default "LVA6E3804001")
  -V      Device ID (binary) for build firmware (0x6e38)


NOTES:
1. Bootloader (and often branding) is not necessary
2. Branding partition optionally contain branding header (can be created with -h option)
3. All partitions seen in such firmwares is "Squashfs filesystem, little endian, version 4.0, compression:gzip"