My Mighty Debian Squeeze 64-Bit

People always run after high performance and less resource-hogging computers and operating systems. In that run they stumble upon barely usable linux distro forks with lxde or xfce environments, or go for big muscle hardware such as core i7 extreme processors, latest intel chipset mobos, discrete graphics cards and the latest maximum memory modules. May be out of ignorance.

I'm also a speed freak. Here's my take for speed.

Hardware: Intel H61 board, Pentium G620 processor, 8GB Corsair DDR3 1333MHz RAM, Atheros LAN Card, Intel HD 2000 Graphics on the same die of the CPU, 32GB Kingston SATA II SSD as / partition + Western Digital Blue SATA II TB HDD as /home partition.

OS: Debian Squeeze 64Bit, backported 3.2 kernel, mesa, drm and xorg manually backported from Debian Wheezy repository.

Package Repos: Debian squeeze, backports, mozilla-debian, debian-multimedia, google and debian wheeze.

Desktop Environment: Gnome 2.30

Software: LibreOffice 3.5, Gimp 2.6, Mplayer and Totem with all codecs and browser plugins, Iceweasel (Firefox) 13, Icedove (Thunderbird) , Sun Java and Netbeans full suite, GCC + G++ along with Code:Blocks, Full Wine suite, and the fat repertoire of media players, audio/video editors, remote access/desktop sharing tools, mysql server, client and admin, a plethora of games and tons of system utilities and recovery tools.

Speed benchmarks: Booting 8 secs, libreoffice startup 1 sec, firefox 1 sec, gimp startup 2 secs, and surprisingly netbeans startup 3 secs. Initial memory footprint is just 130MB. You can't expect more.

Tweaks I did: Optimized SSD to use trim (noatime,discard option in the /etc/fstab of the ssd drive), disabled ipv6, changed /etc/hosts to look for localhost whenever possible instead of searching and reaching there, removed swap partition, removed initram disk, put all my driver modules directly into the kernel so as to avoid seeking initram. Finally cleaned all the unnecessary locale files, symlinks, orphan files and then a few tweaks on gconf-editor. Finally cleaned the gnome config residues (after installing all the software I needed) with gconf-cleaner.

Here's the testimony video, watch it in HD 720p format full screen:

Caitlyn and Linux Hardware Support

Only this morning I saw a post by Caitlyn Martin on tuxmachines.org. About "Linux Hardware Support Myths and Legends" . Funny as always - flaming, ranting and what not!

Come on Caitlyn, admit, Linux is still not ready for consumers. It's never going to be considering the control, complexity and its nature of development. We all love linux. We can tinker our way to use it at our homes and offices. We'll keep on using linux, and we are not sad or sorry if linux doesn't make it to the mass adoption. But your adamant post is laughable at the best. Numbers tell, if there was a pinch of truth in your statement linux desktop would have enjoyed comparable marketshare like the one from Redmond. But 1-2%!

You wrote, "Linux is compatible with more hardware than any other OS bar none. That certainly includes Windows. Try installing Windows 7 on some random laptop from scratch and see how much is missing or unsupported without third party drivers. My experience doing Linux installs for my customers is that a lot of off the shelf hardware "just works" and the rest needs proprietary drivers downloaded to make it work, just like Windows. There is, indeed, some hardware that doesn't work with Linux and years ago that was a real issue. The fact is that more and more manufacturers are supporting Linux well and other drivers have been adequately reverse engineered."

Partly right, linux does support maximum hardware out of the box. But that other OS supports all of the hardware, though not all out of the box. Besides, the maximum number of hardware that linux supports is not as good or simple as it is in that other OS. Compare the installation procedure and performance of modern ATI and NVidia graphics cards on linux with that other OS. Linux fails from a long margin. Moreover, the support is both complicated and buggy most of the time, and not feature-complete.

Caitlyn, please try any of the recent Northern or Southern Island ATi Radeon graphics card on your favorite linux box. Do the same on that other OS. Compare the performance and installation procedure. On that other OS, all you've to do is to pull in the software (just one executable file) from AMD and install it. Your favorite distribution with modern kernel and gallium drivers will readily support the Northern Island ATi chip out of the box. But the performance will be shoddy at best. Then you will search your distros repo or browse the manufacturer's website for proprietary drivers. Download and install the packages. Graphics still won't work the way it does on that other OS. Then you will look for vaapi wrappers, configure the media player settings, bla..bla..bla.. In linux it's not just a driver package, you've to fight with xorg, kernel, drivers, wrappers and decoders. After this big fight your distribution may play your 1080p hd stuff. But again, not as good as on that other OS.

Audio driver scenario is no different. The point is, Sound and Graphics support in linux is very complicated and is always in a catch-22 stage. Admit it!

Here's a copy of the discussion thread on her post. Just imagine how mis-informed and adamant Caitlyn is in comparision to the mature, practical and realistic Jack.

By Jack on May 10, 2012 11:21 AM

Having used Linux since the end of the 90'ies i certainly agree that hardware drivers are not really a big problem. But for some, it really is.

Therefore one should never claim "pick this or that distro - it works out of the box" unless one in fact has experience with the exact combination.

If you do recommend where you should not, you are likely to be the creator of a user very hostile towards Linux, thus a true credibility killer.

Another wrong thing to do is recommending Linux with the ambition to make a Linux enthusiast out of the victim. Recommend (and if possible assist in installing) Linux on basis of the potential users needs and capabilities.

Forget your own preferences - it's all about the potential user, as long as you are sure that you are able to assist.

Now, I've got some shocking news!!
There are no perfect Linux desktop environment, and there are no perfect Linux distribution. There are probably 20-30 distros and 4-5-6 desktop environments that are technically suitable and has the potential, but none of them are really there.

We, as enthusiasts, are able to tweak a distro or a desktop environment into submission. The regular users who just want a neat piece of equipment to work well are not.

Where are the distros for consumers? They don't exist.

By Caitlyn Martin in reply to comment from Jack on May 10, 2012 12:58 PM

Jack: I have some shocking news for you. Any of the major Linux distributions are consumer-ready. That's been true for at least a decade. Any of the major Linux desktop environments are consumer ready. That's been true for at least a decade as well. The current generation of desktops on Windows and even on MacOS are based on ideas that first appeared in Linux. See my recent article on the subject. If those Linux distributions aren't "really there" then certainly Windows and MacOS are even less ready for consumers. You are certainly right that there is no perfect Linux distribution or desktop. There is no perfect OS, period. Linux is in no way more flawed or less ready for consumers than the other options out there.

I see the second part of your comment the same way I see the articles proclaiming that Linux hardware support is terrible: as spreading more fear, uncertainty and doubt for no good reason.

Seems, evangelists like Caitlyn are more of problem than solution to the badly integrated and ever-forking open source OS.

Why Opensource Xorg/Gallium drivers suck on linux desktop

They suck for sure. Nothing much required to prove than showing up the status of xorg/gallium drivers for ati radeon as of 9th May 2012. Have a look at the stuff (marked red) that's not working perfectly. The current situation in modern ati graphics chips almost wards off anybody from using linux. And it doesn't seem to go anywhere till couple of years. The current status shows only a fool will buy ATI graphics to rely on open source drivers and run linux on it. What's more enthusiasts say even if the listed features are completed, the performance will no way be comparable with its catalyst counterparts. Pity!

• "DONE" means that it is implemented and relatively bug-free.
• "MOSTLY" means that it is implemented but has some known bugs.
• "WIP" means that someone has started on the initial implementation.
• "N/A" means that the feature is not supported by the hardware.
• "N/N" means that the feature will not be implemented, because a better alternative is or will be available.
• "TODO" means that someone needs to write the code.
• "UNKNOWN" means that the current status of this item isn't known.

2D features	Evergreen	N.Islands	S.Islands
Kernel Modesetting	DONE	DONE	DONE
Max Supported Display	2-6	4-6	6
DRI2	DONE	DONE	DONE
Page Flipping	DONE	DONE	DONE
ShadowFB	DONE	DONE	DONE
2D Acceleration	DONE	DONE	Gallium
Textured Xv	DONE	DONE	Gallium
Decode on 3D engine	WIP	WIP	WIP
Decode on UVD	TODO	TODO	TODO
Hybrid Graphics	MOSTLY	MOSTLY	MOSTLY
Mesa 3D features	Evergreen	N.Islands	S.Islands
3D Driver	r600g	r600g	radeonsi
Primitives	DONE	DONE	WIP
Stippled Primitives	TODO	TODO	TODO
Smooth Primitives	TODO	TODO	TODO
Textures	DONE	DONE	WIP
Hardware TCL	DONE	DONE	WIP
Vertex Shaders	DONE	DONE	WIP
Fragment Shaders	DONE	DONE	WIP
GLSL	DONE	DONE	WIP
Texture Tiling	DONE	DONE	TODO
S3TC decompression	DONE	DONE	TODO
full S3TC	DONE	DONE	TODO
Tessellation Shades	TODO	TODO	TODO
Geometry Shaders	TODO	TODO	TODO
Anti-Aliasing	WIP	WIP	TODO
Anti-Aliasing	DONE	not tested	not tested
Anisotropic Filtering	DONE	DONE	TODO
Hyper-Z	WIP	WIP	TODO
OpenGL Compliance	3.0/4.210	3.0/4.210	3.0/4.210
Output	Evergreen	N.Islands	S.Islands
Dual-link DVI	DONE	DONE	DONE
XRandR 1.2	DONE	DONE	DONE
TV Out	DONE	N/A	N/A
DisplayPort	DONE	DONE	DONE
HDMI Audio	DONE	TODO	TODO
Power Saving	Evergreen	N.Islands	S.Islands
Engine reclocking	DONE	DONE	DONE
Memory reclocking	DONE	DONE	DONE
Voltage adjusting	DONE	DONE	DONE
Thermal sensors	DONE	DONE	DONE
Other	Evergreen	N.Islands	S.Islands
Suspend Support	DONE	DONE	DONE
CrossFire	TODO	TODO	TODO
Compute	WIP	WIP	TODO

Desktop: Debian vs. CEntOS

While every *buntu and *edora moving towards Unity, Gnome3, Cinnamon or MATE, only two distributions remain practical for desktop productivity and fun, they are CentOS 6.* and Debian 6.*. They both will support the good old gnome2 line at least couple years more. However, they are a lot different from each other. Here's a short description on each of them vis-a-vis desktop use.

	Debian	CEntOS
Pros	#1 clean package management. With backports repo now merged with main debian repos and debian-multimedia being very compatible with debian, you can install whatever you like without the being scarred of any adulteration, conflict or breakage. #2 largest no. of packages, roughly 30,000+. #3 flexible installation options - from netinstall, base cd to kmuto backported images, full CDs and DVDs. #4 less memory footprint and disk space usage. #5 support highest no. of architecture - from arm to amd86 and beyond. #6 frequent updates and point releases. #7 larger community and better/quicker support. #8 better hardware support out of the box with unofficial backports/kmuto installation images. #9 very flexible system offering easy customization as per individual needs	#1 very responsive (better than debian) system as a workstation. #2 quicker updates to major productivity suites for office use such as - openoffice, mozila suite. #3 better tested/trusted set of packages. #4 longer (more than debian) support period
Cons	#1 sometimes updates lose the previous configurations, especially printer, though reconfiguring manually resolves the issues	#1 repo conflicts and occasional breakage of package base as rpmforge, rpmfusion, elrepo, remi, elrepo, epel and atrmps don't always work in sync. #2 lesser no. of packages in the repo. #3 no easy customization as per individual needs. #4 smaller community and less no. of contributors

Debian on desktop: 9 pros + 1 con = 8 points
Centos on desktop: 4 pros + 4 cons = 0 points

Of course, the list is not complete at all and may reflect my bias towards Debian. If so, please correct me sending you feedback that'll help me revise the list.

Too much of freedom = Chaos

Q: Why FOSS on Linux desktop did not get traction the way it should?
A: It started up with a Utopia - freedom of choice.

Windows powers around 90% of the desktops worldwide. It doesn't offer much choice. And the little choice it offers is limited to a few application software. For more than 15 years we have just two GUI for Windows - Luna (Pre-Vista) and Aero (Post-Vista). Ask average Windows users about the desktop environment they use. 99% of time you will get a shock response - they have no idea. Or at best the answer will be "Windows". They have just one word "Windows" for the OS, for the desktop environment and everything else. What does it mean?

• people are not so fond of software, they just want to get their job done using some software (often reluctantly), crying "choice" aloud just frightens them
• they don't worry about the source code and the RMS freedom associated with it

99% of normal people don't know how to program and don't give a damn about source codes and freedom of choice. They skip any reference to "source code" and "EULA". Free software is ok, but saying "you can have a look at source code" is definitely not an effective point. Very often freedom of choice becomes a costly affair if you consider the time invested to get your way through these choices before settling at one.

That's precisely why after so much trumpeting of the advantages of FOSS it's struggling to register in the mindshare of the masses. The often said "Resistance to change" is not the only reason holding the opensource platforms back. It's the lack of standards, simplicity, coherence and good applications, plus the ever growing chaos in terms of fragmentation and multiplicity in every possible form.

You need to clean the clutter by dumping 90% of the stuff that make up for freedom of choice. Then you need a benevolent dictator who can apply an adamant standard and QC system to really push FOSS on the Linux desktop forward, but then it won't be FOSS anymore.

It's not the same linux across distributions

Many times I've read this in a lot of prime linux fora - It doesn't matter which distribution you're using as long as it's linux. Then the usual preaching of choice and freedom runs till the end of those particular threads. I don't buy to this generalized statement. Read on to know why, but first let's see how this statement surfaces from the so called evolved linux gurus.

An enthusiast Windows/Mac user jumps on linux enlightened by a friend or being encouraged on the web. He/she tries a so called popular distribution, if unlucky faces multiple problems related to the stuff on the outer layers, the gnu stuff and other OSS stuff which in combination with linux make a distribution. Then googles for a while, visits some fora, gets suggestions from seasoned and noob users to change his/her distribution with some other, where the issues in question are resolved but may face some other bugs. Then some guru drops in and says - linux is linux, doesn't matter which distro, it's best to use one that suits best for his/her particular needs.

Now on to the topic. In theory every distribution is the same, but in practice they are not. A developer or a long time user might feel it same after cleaning the clutter and sorting everything to his or her liking. But the average Joe is not that skilled and doesn't have that patience to tame the OS. A minor quirk that comes in the way might make him/her feel distro A is different from distro B which is quite different from distro C.

It's a pity reality. Linux distributions are so loosely integrated that a minor mistake in putting stuffs together will create major problems. Doesn't matter even if that distribution is byte by byte a recompiled copy or just a derivative of some popular distribution with minor changes here and there. Most often even if the derivative distribution shows superficial changes in skins, branding, selection of default apps or choice of desktop environment, it might influence components lying much deeper in the bundle. For example, take the case of audio stack (click on the image below) on a typical linux system. Look at its complexity and relationship with various components and imagine what can happen with slight mishandling.

Here's an interesting case of Scientific Linux 6.2 and Centos 6.2, both are free recompiled versions of RHEL, both aim to be as much close to the upstream as possible. I started with Scientific Linux, the installation was literally a non-starter on a Dell Optiplex 380. Checked mdsum, changed media from CD to USB to network. No go! However, CentOS had no such problem on the same PC.

Android-x86, Just a Hobbyist Project

Started at mid-2009 Android-x86 project has not been able to offer a well-rounded release so far.

Then, it was a welcome relief for all those loved Android on mobile devices and wanted the same usability, performance and security on their x86 devices such as netbooks and computers.

I was an early adopter of Android-x86 for three basic reasons:

#1 it pumped vigor to some aging PCs (PIIIs, PIVs and Atoms)
#2 it was a tightly integrated project (not like fragmented Linux ecosystem)
#3 performance was great (expected being a mobile OS)

Till date the project has been delivering on those basis reasons, but has not been able to come up with a version worthy of consumer adoption. It always tries to catch up with the upstream, and pushes out unfinished releases (RCs) pretty close to the android releases. But before it could resolve all the issues and bring out a final bugfree release, Android jumps one version or one point up, and Android-x86 people drop it right there and sit together to work on the new upstream offering. Buggy RC stays just there. From Android 2.3 through 4.0, you get just unfinished RCs. I don't dare guess their future releases.

Here's the timeline of recent releases:

 - 2012-02-27: Android-x86 4.0 RC1
 - 2011-11-23: Android-x86 3.2 RC2
 - 2011-08-28: Android-x86 2.3 RC1

Each of the releases has been plagued with one or more of the following issues:

#1 Suspend and resume doesn't work on some targets.
#2 No Ethernet support.
#3 Camera and bluetooth don't work.
#4 Camera recorder doesn't work.
#5 Wifi and Ethernet cannot be turned on simultaneously.

Is it just a product for developers to learn packaging for Android? Or for those hobbyists who don't expect anything more than being able to tinker?

I don't need sex, gnome 3 fu*ked me in the brain

I am not just another gnome 3 hater in the most fashionable and popular way. That's, though I don't like the way it defies the traditional workflow, the biggest problem for me, is something else. It's the shoddy quality of the software, even after one year of its initial release.

Forget the usability, still the gripes are many, ranging from its integration into the system to how it talks with various other core components such as graphics, desktop effects, and the overall stability.

As for usability, I'm ok with putting a few extensions to tweak the desktop behavior, but not, if my graphic card crawls on this new desktop. Searched every forum, tried with gallium3d, failed. Installed catalyst plus vaapi with gstreamer and vlc backends. Still no-go. I am sorry, it's not for me. Moreover, my system wearing this new gnome skin coughs every now and then. Sometimes it stays irresponsive for quite long. That's simply unacceptable.

My Radeon HD 6310 flies on both gnome 2.32 and kde 4.8. I know I may achieve the same performance after some more workaround. Same with system irresponsiveness. But who cares!

 Shoddy software quality, defiant community and bad usability = Gnome 3

How has been your gnome 3 ride? Please don't flame on the task management and workflow, just mention how stable the whole stack has been so far?

MCLinuxPC 2012 - The Whole Kitchen Sink

Kind of bubble sort, distributions come up, tumble down, some grow, some die unmaintained. First we had Slack, then Redhat, Mandy, Mepis, Ubuntu, PCLinuxOS... and now Mint. Most often the popularity of a distribution depends on the degree of "out of the box" functionality it offers, plus how well it integrates the various bits and pieces. IMO, only three distributions championed in this regards - Mepis, PCLinuxOS and Mint.

Now on to the business. Here I am reviewing MCLinuxPC 2012, a remaster that comes from one of my favorite distributions that manages rpm packages on synaptic, by Sefy. No awards for guessing. But I won't reveal the name for two obvious reasons: first, this remaster has gone too far in including the software not allowed to be legally redistributed, second, it's not been publicly announced.

The good thing is, that legality neither applies to him in Israel, nor me in India. Besides, Sefy has taken all care to rebuild some base packages related to lsb, issue, grub, etc., altering every reference of that famous distribution. For now, the remaster is floating across a few close friends.

Hope it doesn't violate any rule.

Here's the review.

I'm a big time fan of that popular distribution for one solid reason - it never failed on my hardware. It's neither the most beautiful, nor the most cutting edge distribution. Stable, and may be a little conservative, but it just-works, you won't have to fiddle much. You are ready to go the very next minute after installation. Having said that, seems it's a great feat for the remaster to maintain that quality, after loading so much extra stuff.

I won't repeat here the livecd experience and the installation. It's pretty much similar to that big distribution. So, fast forward to the installed environment.

Hardware

As of now the remaster has been running on four different set of hardware at my home and office -  a Dual Core Pentium Dell Optiplex 360, an old PIV Compaq, an Asus Eee PC 1215b with AMD Fusion C-50, and an Intel Essential D410PT nettop. Some of those machines have housed Debian Squeeze, Arch and Ubuntu Natty also. Let's see how well MCLinuxPC fares against those veteran distros.

Booting

As always, no surprises here. MCLinuxPC booted just fine across all the four different configurations. Of course the bootup time was a few seconds more than Arch and Debian, it's the price for its heavy customization. The freshly booted desktop seems to be pimping Windows 7 and Mac OS on top of the default KDE 4.6.5. Under the hood there's a bfs patched 2.6.38 kernel. The application software selection is huge and all-encompassing, we'll see later. The look is quite different from its parent distro. It doesn't do blue and gray that much.

Memory Consumption

Memory consumption right after booting was around 350MB on all the machines, except that EEE PC 1215b, where it was around 400MB. No bad for a KDE 4 remaster.

Performance

I can't site any numbers here. As far as my perception goes MCLinuxPC is as responsive as Natty, Arch and Squeeze on all the machines except Eee 1215B. Squeeze was the most responsive of all on this tiny computer. 1GHz Ontario C-50 APU is not enough for KDE 4, may be.

Desktop Experience

No surprises here. For the first time my Eee 1215B worked as expected. Graphics, Touchpad, Wireless, Webcam and Bluetooth behaved smooth. The other three machines worked well too including my old PCI Hauppage analog TV tuner on a dated PIV system. Apple Trailers, Microsoft Media Server, flash videos, MP3 et al played. Oh the good xbmc, the local media files were shelved the way they should be. MCLinuxPC does a very good job of managing additional languages through its Localization Manager. For the rest, there's good old MCLinuxPC Control Center.

The systems are stable - I've been working on the machines for last 4 days, so far no crashes related either to KDE or kernel.

Applications

MCLinuxPC outshines almost every other distribution in this department. There is the whole kitchen and sink. The system utilities, internet suite, productivity suites, multimedia suites + xbmc + codecs + media converters, graphics suites, games, emulators, and believe it or not, the universal computer learning suite comprising the full jdk, gcc, g++, assembly, mysql. Wow! A superb selection. Be it sharing your stuff, using internet, doing some serious office work, converting your media, syncing your devices with PC, managing security, cleaning the system, sharing peer desktops, or whatsoever, you name any popular modern system software or application software, it's all there. Also, there's a balance of the software - not much duplicity. Under 2.6GB it packs so much applications that the good old synaptic seems an overdo. You can live your life without using it ever, except for updating the system, if you like.

Here's a list of applications that comes with MCLinuxPC, sorted items menu-wise:

Communication: qtadb for android barry backup synce kde pda manager Configuration: ATI catalyst manager 3D acceleration configuration cairo dock chbg compiz manager emerald ezswitch firewall floppy formatter google gadgets kde grub manager gtk theme switch hardware information install MCLinuxPC localization libreoffice manager network center ntfs configuration manager nvclock partition manager pulse audio manager redo mbr samba configuration unetbootin user administration kwallet manager Development: diff/patch configuration teamviewer kompozer complete gcc, g++, nasm, assembly (nasm), sun jdk, mysql Text editors: medit vi kwrite File tools: bleachbit krename krusader midnight commander kleansweep Games: complete bundle from arcade, board games, puzzles, strategy, etc. Graphics: imagemagick gui gimp kolourpaint kamoso gpicview digikam picasa ksnapshot xsane kruler Sound: amarok songbird kscd kradio timidity cd ripper nvidia tv output floola volume control sound recorder Package management: dupclean synaptic libreoffice manager opera widget manager

Emulators: wine - Windows Emulator desmuke - Nintendo DS dosbox - DOSbox epsxe - Playstation One xgngeo - NeoGeo nintendo - Nintendo hu-go! - HuGo pcxs - virtualbox visualboy - Advance Gameboy winetricks gsnes - Sega Master System & Genesis yabause - Sega Saturn zsnes - Super Nintendo Monitoring: thinkpad battery monitor desktop widgets netapplet removable media utility system monitor xkill view disk usage Terminal: konsole xterm Archiving: acetoneiso k3b nero ark file roller iso master nepomuk backup p7zip gui Internet: google earth qbittorrent filezilla dropbox teamviewer firefox chrome opera kdesktop sharing krfb thunderbird kopete kppp groupware blogging putty tightvnc xchat irc tkpppoe Office: libreoffice note taking tools time management adobe reader personal organizer artha calibre Video: imagination cheese coriander me tv xbmc media center tv time realplayer vlc video4fuze mobile media converter kplayer winff gtk-recordmydesktop

Conclusion

Question: So, what's so good about Sefy and his remaster?
Answer: MCLinuxPC is godsend for all those who love linux but can't stand the annoyances and pains that come with it. Yes, it's fat, it's not as clean and swift as a default Arch or Debian setup. But that's a small tradeoff for the amount of goodies you get. You only need to download just the remastered iso, and have a secure, modern, entertaining and productive life without the need for any extra bit or piece. Another big point is this is the only Linux with "out-of-the-box" adb pre-configuration for immediate access to Android phones.

AMD Opensource Gallium is a PITA

Last night I was reading an article comparing proprietary catalyst drivers with opensource gallium drivers. It was an eye-opener. Cases such as this shitty/shoddy performance of gallium drivers is the reason why people prefer proprietary blobs to FOSS bits and pieces. Here is just an example. For more, please visit http://www.phoronix.com/scan.php?page=article&item=amd_rv770_linux31&num=2