Q: compiling kernel modules on OS6 (dvb_hdhomerun)

It's probably best to keep it simple: use the 6.3.3 firmware image and kernel sources from this post: https://community.netgear.com/t5/ReadyNAS-Beta-Release/OLD-EARLY-ACCESS-ReadyNASOS-6-3-3-T153-Beta-12-OLD/td-p/931949

Be aware you have to change the kernel on the hidden internal flash. If this goes wrong, you probably end up with a bricked nas.

Upgrade firmware to 6.3.3

Just to be sure: backup your module tree after nas is back online, running 6.3.3 :

cp -Rpv /lib/modules/3.12.36.RNx86_64.2.2 /lib/modules/3.12.36.RNx86_64.2.2-backup

Install utils to built from source:

apt-get install build-essential libncurses5-dev

Download kernel sources and extract to /home/cliff/linux-3.12.36-38 

copy the Netgear config to the kernelsource root:

cd /home/cliff/linux-3.12.36-38

cp .arch/x86/configs/readynas_defconfig ./.config

Be sure to keep the original readynas_defconfig intact and unchainged.

Then add the DVB_core module to the kernel:

From /home/cliff/linux-3.12.36-38 :

make nconfig

go to Device Drivers --> Multimedia support

select Digital TV support and press space bar

then select DVB Network Support and press space bar

Both should show an asterisk between the brackets now.

Press F6 (Save) and F9 (exit).

The kernel config is OK now.

Now enter

make

and grab some lunch. Process could take 45 - 60 minutes.

after completion, the new compressed kernel image can be found in

linux-3.12.36-38/arch/x86/boot

with the name bzImage.

You now have to boot your nas with this new kernel. This is the tricky part that can lead to a bricked unit. If it goes wrong your nas won't boot anymore. Ever.

First you have to make the internal flashdrive to show up. Arter done that, be very careful what you do. You have to edit SYSLINUX.CFG, and I've experienced twice that the file got scrambled. In that case, the nas won't boot anymore. I found the following procedure to work.

First, let the internal flash show:

echo -n "1-1:1.0" > /sys/bus/usb/drivers/usb-storage/bind

This makes the internal flash show up in /media/USB_FLASH_1

Now copy the new compressed kernel to the flash, under a UNIQUE name; mine is k3-12-36.dvb

cp /home/cliff/linux-3.12.36-38/arch/x86/boot/bzImage /media/USB_FLASH_1/k3-12-36.dvb

Be sure to use old-school MS-DOS 8.3 file name format.

Now you have to add an option to the boot menu in SYSLINUX.CFG.

First, copy the oringinal file. Go to /media/USB_FLASH_1 and

cp SYSLINUX.CFG SYSLINUX.CFG.org

Now add a boot item, using a editor (vi or nano), so the last lines of SYSLINUX.CFG look like

label TestDisks
kernel kernel
append initrd=initrd.gz console=ttyS0 reason=test_disks

label Kernel-DVB
kernel k3-12-36.dvb
append initrd=initrd.gz console=ttyS0 reason=normal

(the label TestDisks is the last label from the original SYSLINUX.CFG).

Save the file and go back one directory (to /media).

Check the file SYSLINUX.CFG is still readable:

from /media:

cat ./USB_FLASH_1/SYSLINUX.CFG

if the file is readable, do

sync
sync

(so twice)

and reboot immedaitely after that.

If the file is not readable, start over from the original one you copied.

After reboot, the nas still uses the 'old' kernel. To change to the new one, shutdown and let it boot in the bootmenu. Using the led patterns from the manual, you can detect when the cycle has vome to TestDisks; the one after that is your new kernel.

When it boots the new kernel without problems (and has ran for hlf a day or so), you can change the default boot option at the top of SYSLINUX.CFG to Kernel-DVB.

And while you're at it, change the baudrate in the first line from 9600 to 115200 if you want to use a serial connection (OS6 uses 115200, where 4.x.x. uses 9600).

At last, when the new kernels seems to work OK, install the new modules.

Go to the sourceroot /home/cliff/linux-3.12.36-38 and enter

make modules
make modules_install

make modules_install will overwrite the original modules in /lib/modules/3.12.36.RNx86_64.2.2 so you need to verify yourself whether all modules from the backup directory are still in the new directpory and if not, copy them yourself.

In the new /lib/modules/3.12.36.RNx86_64.2.2 is a link to the location of the source you used, so when you compile dvb_hdhomerun it will find the correct kernel files.

The hdhomerun kernel modules are kernel-dependent, so when you upgrade to a new kernel you have to recompile them.

Good luck, please let us know how it worked out.