Pi vs BeagleBone-Black

Morgaine Dinova wrote:

 

My redux from the last few exchanges is that Pi is seen as a vehicle for the initial stages of  engineering education (which of course is true, and very welcome), but owing to the various areas in which the board and SoC are closed, it's not a vehicle for medium or advanced engineering education.  The complex bits are restricted to just a privileged few.  Not ideal, but you can't win them all.

 

It's a pity though --- it didn't have to be so.  Whatever the obstacles, where there is a will there is always a way, and if the will were there, the whole thing could have been made open hardware.  Or, more optimistically, can still be made fully open hardware some time in the future.  Full disclosure rights to so-called "proprietary IP" can be purchased --- it just requires sufficient will to allocate funds to it, aided by good negotiating skills to convince the design rights holder that their horrible USB design core isn't worth much anyway.

 

Even the VideoCore will in time become obsolete and superceded by something better.  How about planning for that time, and getting ready to acquire full disclosure rights to it?  Where there is will there is always a way.

This follows a bit what I was just saying.  Whenever the foundation released more information, the overwhelming response was negativity that they weren't making it more opened rather than positive praise for the work they were accomplishing on the open source front.  Personally, I look for the point at which a device becomes effectively completely open sourced.  Take the USB stack like we've been discussing.  There might be a handful of individuals who actually want to dig into making their own USB driver even fewer who want to mess with the GPU at a lower level than the 4 or 5 interfaces that have been opened up from the ARM side of things.

I guess what I'm trying to say is that we need more of a weighted average when it comes to talking about how open a board is and we need to be more ready to praise when anyone gets additional documentation released instead of our default response of "stop be proud about only getting this much".  I definitely need to do some more research into how the bone lets you work with the GPU, but it seems like in terms of openness they both fall short in the same GPU location.  The pi might be slightly more open in that you can do more tweaks via the config.txt file, though from our current definition we'd probably rank the Bone as more open for obscuring the GPU.  sigh.

mynameisJim wrote:

 

As individuals in favour of open source products, I feel like we're almost fighting for things to go the wrong way.  When it comes to ranking something on how open source it is, I think that we should deduct points for hardware obscured code and consider how much usability and configuration we're giving (such as with config.txt) and award such devices for being more open.

IMHO, the problem with the open source argument is that when you break down one barrier there's always another one behind it. Get the source to the bootloader, then you'll also want the source to the compiler for it and on it goes... Sooner or later you're asking for the litho masks so you can produce your own silicon, then you'll need the wafer fab machines software to be open source and the design of the machine too. (and the software used to design the machine!)  But somewhere you have to draw a line and say this is as far as we go. The argument then becomes about where the line is and about who can make how much money from either side of that line. Suddenly it's not just about open source anymore.

Personally I'm reasonably happy with the line being at the hardware as long as the hardware is documented well enough to allow the software to be written to use the hardware. The flaw in my idea comes when the 'hardware' really isn't hardware but is something implemented in software pretending to be hardware. You now have a blurry grey line instead of a nice crisp one.

That's about as far into that can of worms as I'm prepared to go. Suffice to say that I think as long as we have a system that uses money then we'll never be able to make everything open as there will always be someone seeking to make a profit by keeping something secret and therefore being able to sell it at a premium. As Billy says, don't have to like it but that's just the way the world works.

mynameisJim wrote:

 

but it seems like in terms of openness they both fall short in the same GPU location. 

I think I've said it before, but I believe that the GPU on any board will always be the sticky point. None of them are any better than the rest. There's simply too many people/companies intent on protecting their 'IP' and they don't care if we believe in the concept or not. Given this stuff always tends to be a minefield of patents and cross-licensing, I can't see there being improvements anytime soon.

There isn't a GPU in existence in the ARM world that is open, so the manufacturers are all equally bad in that regard.

That said, the Lima driver people are making great progress with ARM's own MALI GPU, so perhaps ARM licensees like Allwinner that use MALI are unwittingly going to be leading the way towards open ARM hardware despite lacklustre support by the companies themselves.

It's ARM's loss really.  ARM took a step backwards in their excellent "profit by licensing" model when they didn't make MALI completely open and reverted to the utterly dumb "profit by secrecy" wishful thinking.  Message to ARM:  1) You failed totally. 2) Get rid of the person who suggested that  stupidity.  All it did was put a throttle on ARM's fantastic profit stream.

mynameisJim wrote:

 

I guess what I'm trying to say is that we need more of a weighted average when it comes to talking about how open a board is

No we don't need a "weighted average".  It's either fully open or it's not.  You can't be partially pregnant.

Engineers tend not to be concerned with GPUs on SoCs not being open (probably because they don't use them) and so SoCs in which everything but the GPU is fully documented are regarded as "open hardware".  It's easy to understand that point of view --- why care about something in which you have no interest?

In an ideal world everything will be open, but only the PC world has examples of that --- most Intel and AMD GPUs are fully open.  In the ARM world we're lagging badly.  In the absence of interest in openness from any ARM licensee, those who use MALI seem destined to win just because that's where the open source community is active.

selsinork wrote:

 

I think I've said it before, but I believe that the GPU on any board will always be the sticky point. None of them are any better than the rest. There's simply too many people/companies intent on protecting their 'IP' and they don't care if we believe in the concept or not. Given this stuff always tends to be a minefield of patents and cross-licensing, I can't see there being improvements anytime soon.

I think Parallella has a good shot at improving the situation.  I believe you can use the Epiphany chip as a parallel processor for GPU functions, and then use the FPGA to blast the result out HDMI.  You can also use the FPGA for GPU tasks that Epiphany doesn't do well.  If it's indeed true that the data paths exist to do this, it's just SAMP (simply a matter of programming).

Anyone know how the open-source Lima driver for ARM's Mali GPU is going?  (Wrote this before seeing Morgaine's comment above!)

selsinork wrote:

 

Personally I'm reasonably happy with the line being at the hardware as long as the hardware is documented well enough to allow the software to be written to use the hardware. The flaw in my idea comes when the 'hardware' really isn't hardware but is something implemented in software pretending to be hardware. You now have a blurry grey line instead of a nice crisp one.

It's not a blurry line as long as the following test can be applied to it:  "Is it field-programmable?"

Hardware/software/firmware/donutware are all immaterial in this regard.  The acid test is whether it's possible for the device to be reprogrammed in the field by anyone at all.  If a binary blob can reprogram it, then so can a user if the programming information is available.  This rule is simple, easy to understand, and clear to apply.

Morgaine Dinova wrote:

 

"Is it field-programmable?"

Yes, but we're not going to tell you it is, therefore it's not

Or more likely, yes but we're not going to tell you how.

Morgaine Dinova wrote:

 

It's ARM's loss really.  ARM took a step backwards in their excellent "profit by licensing" model when they didn't make MALI completely open and reverted to the utterly dumb "profit by secrecy" wishful thinking.  Message to ARM:  1) You failed totally.  2) Get rid of the person who suggested that stupidity.  All it did was put a throttle on ARM's fantastic profit stream.

My guess is that ARM is afraid of nuisance patent lawsuits if they open the Mali documentation.  My evidence for this is that if you register to get ARM architecture documentation from the ARM website, you have to promise that you're not going to use it to accuse ARM of patent infringement or provide the documentation to a third party for that purpose.  I haven't heard of ARM trying to stop Lima.  Maybe ARM figures that if Lima reverse-engineers the API, ARM can say that Lima's documentation is not how Mali actually works so there's no evidence that ARM infringes your silly patent.  (IANAL, but I read that this is the easiest patent defense: we don't infringe, so whether or not your patent is valid is moot.)

John Beetem wrote:

 

I think Parallella has a good shot at improving the situation. 

and if it works it'll be a huge win for them. All it really needs is the support for the sorts of media operations that the likes of h264 needs and it could be a winner.  Well that and rendering facebook pages quickly

Morgaine Dinova wrote:

 

In an ideal world everything will be open, but only the PC world has examples of that --- most Intel and AMD GPUs are fully open. 

Minnowboard comming soon to a disty near you!