DSL-Firmware bpatch question

For Developers
1

Hi,
I've been looking around the web, searching for the right VDSL-Firmware for my FB7360 with Lede.
I could find this Link http://xdarklight.github.io/lantiq-xdsl-firmware-info/ with the following manual for extracting the source files:

    7z e FRITZ.Box_WLAN_3370.103.06.30.image -r filesystem.image
    7z e filesystem.image filesystem_core.squashfs
    7z e filesystem_core.squashfs lib/modules/dsp_vr9/*

    bspatch vr9-B-dsl.bin vr9-A-dsl.bin vr9-A-dsl.bin.bsdiff
    bspatch vr9-A-dsl.bin release-vr9-A-dsl.bin release-vr9-A-dsl.bin.bsdiff
    md5sum -c release-vr9-A-dsl.bin.md5sum

My question to this:
What is this guy doing with the bspatch command?
When I'm using the vr9-B-dsl.bin without patching it, I'm getting a sync with the dslam and when I'm using the patched one, I'm also getting a sync?!
So what's the difference? Which one should I use? The patched one, or the original one?

Thanks in advance!

Best regards

2

NAME
bspatch -- apply a patch built with bsdiff(1)

SYNOPSIS
bspatch oldfile newfile patchfile

DESCRIPTION
bspatch generates newfile from oldfile and patchfile where
patchfile is a binary patch built by bsdiff(1).

 bspatch uses memory equal to the size of <oldfile>	plus the size of
 <newfile>,	but can	tolerate a very	small working set without a dramatic
 loss of performance.

SEE ALSO
bsdiff(1)

3

Thanks for the answer.
But what exactly does this mean to the dsl chip?
Why is the patch needed in this case? Better performance? More compatibility ?

4

Sorry don't know.
I would assume you want to use the patched firmware otherwise why bother patching

5

The first patch rewrites the Annex B capable firmware into an Annex A capable one. Those are the standards for ADSL. (OpenWrt actually does the same with the firmware it comes with. As the firmwares differ only in small amounts, it saves quite some space to only include one and the difference to the other.)

As for the second patch I'm not sure what it does. I could only hazard a guess based on the filenames, but that doesn't help anyone looking for concrete information.

Quite simply because the Annex does not matter for VDSL.

6

Thank you very much for explaining takimata! :slight_smile:

So if my provider is using Annex B for ADSL, i don‘t need to patch, right?

Thanks!

7

That really depends on the firmware. This one apparantly not.

Then again, OpenWrt (LEDE 17.01 or later at least, I believe 15.05 too, but really why would you install anything older than 18.06-rc2) already comes with a quite capable firmware. You should really only have to supply your own if your line is VDSL+vectoring.

8

Oh, ok! Thats the point, I just used because of vectoring :slight_smile:

Thanks for the explanation again!

9

Hi again,

yesterday I've extracted a new dsl-firmware from FRITZ.Box_Fon_WLAN_7360.124.06.85.image. When I used the vr9-B-dsl.bin without patching it, I got a sync of 38 mbit/s. I couldn't figure out the problem, so I tried using bspatch to patching it with "release-vr9-B-dsl.bin.bsdiff". The firmware lost 8 kbyte and worked with 110 mbit/s sync. So there must be some reason for patching it. It's not only relevant for adsl!?