Not logged in
Log in now
Create an account
Subscribe to LWN
LWN.net Weekly Edition for December 5, 2013
Deadline scheduling: coming soon?
LWN.net Weekly Edition for November 27, 2013
ACPI for ARM?
LWN.net Weekly Edition for November 21, 2013
It is however a closed platform on which it happens to be possible to run Linux in a co-processor with help from the proprietary boot loader and platform firmware.
Loading keys from Microsoft PE binaries
Posted Mar 13, 2013 19:32 UTC (Wed) by dlang (✭ supporter ✭, #313)
except that the documentation is out there for you to develop your own bootloader (you just get the broadcom SDK for the chip)
Posted Mar 14, 2013 12:01 UTC (Thu) by nye (guest, #51576)
Really not even remotely the same. The RPi is an exceptionally closed platform; in order to do anything with it you need to use Broadcom's binaries. Bear in mind that the main processor is actually the GPU; the processor that Linux treats as the CPU is in fact completely controlled by the graphics firmware.
> except that the documentation is out there for you to develop your own bootloader (you just get the broadcom SDK for the chip)
To the best of my knowledge, that's untrue. It's a question that gets asked pretty frequently though, so if you know better than anyone else, you could do many people a favour by posting that information on the RPi forum.
In general, I think the RaspberryPi is a textbook example of where we don't want things to go if we want open systems under the user's control.
Personally I consider many of the foundation's public statements to be borderline fraudulent, and have a hard time with continuing to assume good faith given their behaviour and response to criticism thus far.
I recommend that nobody buy an RPi, for any purpose; it is an enemy of Free Software.
Posted Mar 14, 2013 16:18 UTC (Thu) by Jonno (subscriber, #49613)
> Bear in mind that the main processor is actually the GPU; the processor that Linux treats as the CPU is in fact completely controlled by the graphics firmware.
That is true. To my knowledge, the only other common system where Linux were run on a co-proessor and completely at the mercy of another OS the original PS3 (where the system was under the control of OtherOS running at one of the SPU's, while the PPC core and remaining SPU's was allocated to Linux, with a limited fw interface to OtherOS to access the HDD and display hardware). As I recall, the PS3 was lauded for it's comparative openness at the time (well, until they removed OtherOS from the firmware)...
To my mind, the only thing that makes the Pi "worse" than the competition is that the binaries are located in a FAT FS on an SD-card, rather than in on-board flash, and thus more obvious to the casual observer. That it simplifies fw upgrades (and downgrades, making a PS3-like bait-and-switch by Broadcom impossible), seems to be ignored.
The Pi situation is by no means "good" from a user freedom perspective, but it's not really any worse than any other arm, x86 or ppc system in existence.
Posted Mar 14, 2013 17:24 UTC (Thu) by johill (subscriber, #25196)
I believe this is a misrepresentation, Linux/OtherOS was/is running in a hypervisor, not on the bare metal other CPU. The SPUs couldn't control the main CPU anyway, they're pretty much just signal processing units.
Posted Mar 14, 2013 19:14 UTC (Thu) by dlang (✭ supporter ✭, #313)
show me anything along the lines of the following tutorial
Also, since the broadcom chip is sold for embedded uses, you can get everything you need from broadcom to develop your own code to replace the Pi foundation provided (note, not broadcom provided) bootloader binaries.
Frankly, I wish that the source for this was available, but given the current patent mess, the choice is betwen providing this bootloader as a binary, or having to pay patent licensing fees for the video codecs in every Pi sold. And in this situation I prefer keeping the price down to given money to the patent extortionists like MPEG-LA.
And since this is on the SD card, it's always possible for this to change in the future. Either the patent mess could change, or someone else could write a replacement bootloader and make it available.
While I fully understand the feeling that this is not ideal, calling something that has put over a million devices running Linux into people's hands "and enemy of Free Software" is cutting off your nose to spite your face.
Posted Mar 18, 2013 13:02 UTC (Mon) by nye (guest, #51576)
If that were the only criterion, we would laud TiVo as a far greater force for free software.
Regardless, the thing that really upsets me about the RPi is the level of double-speak that comes from the foundation. If they were to acknowledge how closed their platform is in comparison to a standard PC that would be one thing, but to keep beating the drum about how open and amazing they are leaves a bitter taste.
Also, they've been pretty unpleasant to people who have anything critical to say about the project (and I don't mean me; I mean people who are more polite). The effect has been to give me a very powerful impression that they don't really care about openness at all except as far as it can be used for marketing purposes.
Posted Mar 18, 2013 23:29 UTC (Mon) by dlang (✭ supporter ✭, #313)
Second, the Pi allows you to run with everything running in the Linux space being open source, this is FAR better than most computers with reasonable graphics do.
If you are so worried about how the binary blob in the GPU can access the memory that the Linux kernel uses, then you had better not have any PCI cards (especially not any PCI graphics cards) in your desktop PC, because the binary blob firmware running on any PCI attached device can access any memory in the system (unless you are using IOMMU and the device driver has been written to limit the hardware)
Would it be better if the bootloader/GPU firmware was open? of course it would be.
As for the reaction from the people at the Pi foundation to 'polite' criticism, given the abuse that they have suffered, I think it's a matter of the well being poisoned, after being abused by so many obnoxious people, their patience is long gone and they don't react well to anyone. This doesn't mean that they don't care about openess, it's just part of human nature.
> If they were to acknowledge how closed their platform is in comparison to a standard PC that would be one thing
I don't believe that their system is closed compared to a standard PC, so I can easily see how they don't either.
Copyright © 2013, Eklektix, Inc.
Comments and public postings are copyrighted by their creators.
Linux is a registered trademark of Linus Torvalds