Enabled baby jumbo frame (1508) support for bridging.

README.md

@@ -1,10 +1,38 @@
 # Firmware for the Zyxel VMG3925-B10B
 
-Original README follows:
+V5.13(AAVF.11)C0 for a Zyxel VMG3925-B10B with baby jumbo frames (1508) enabled. The stock Zyxel firmware is limited to 1492 MTU when bridging.
 
----
+## Instructions
 
-ReadMe for VMG3925-B10B(V5.13(AAVF.11)C0)
+1. You must use the 32-bit version of [Ubuntu 12.04.5 LTS Desktop](http://releases.ubuntu.com/12.04/) to build this firmware. Using anything else is likely to cause buildroot to fail and generate nothing or a broken firmware image.
+
+2. Run `sudo apt-get update`
+
+3. Run `sudo dpkg-reconfigure dash` and select no.
+
+4. Install necessary tools with `sudo apt-get install -y g++ flex bison gawk make autoconf zlib1g-dev libncurses-dev git subversion gettext`
+
+5. Clone this repo somewhere.
+
+6. Change to cloned repo directory.
+
+7. Run `make dirclean`
+
+8. Run `make`
+
+9. The complete firmware image is bin/brcm963xx/zyxel/ras.bin and should be roughly 28MB. Flash it using the web interface of your VMG3925-B10B.
+
+## Notes
+
+The Broadcom SDK configuration menu is a trap. The Zyxel firmware doesn't use the SDK configuration in the menu and specifically looks at target/linux/brcm963xx/bcmsdk-416L05-AAVF-config-3.4 instead. Any changes made in the menu for the Broadcom SDK will be ignored.
+
+## License
+
+GPL
+
+## Original README follows:
+
+```ReadMe for VMG3925-B10B(V5.13(AAVF.11)C0)
 
 
 0. Introduction
@@ -84,3 +112,4 @@ ReadMe for VMG3925-B10B(V5.13(AAVF.11)C0)
     You can use it update VMG3925-B10B by using the firmware update procedure.
 
 
+```

target/linux/brcm963xx/bcmsdk-416L05-AAVF-config-3.4

@@ -2115,9 +2115,9 @@ CONFIG_ROOT_FLASHFS="ro noinitrd"
 # CONFIG_BRCM_KTOOLS is not set
 CONFIG_BCM_EXT_SWITCH=y
 CONFIG_BCM_EXT_SWITCH_TYPE=53115
-# CONFIG_BCM_JUMBO_FRAME is not set
-# CONFIG_BCM_USER_DEFINED_DEFAULT_MTU is not set
-# CONFIG_BCM_USER_DEFINED_DEFAULT_MTU_SIZE is not set
+CONFIG_BCM_JUMBO_FRAME=y
+CONFIG_BCM_USER_DEFINED_DEFAULT_MTU=y
+CONFIG_BCM_USER_DEFINED_DEFAULT_MTU_SIZE=1508
 # CONFIG_BCM_IGNORE_BRIDGE_MTU is not set
 CONFIG_BRCM_MEMORY_RESTRICTION_OFF=y
 # CONFIG_BRCM_MEMORY_RESTRICTION_16M is not set