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Blobless Linux on Raspberry Pi

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Re: Blobless Linux on Raspberry Pi

#22
post #7

Earlier quoted context omitted.

You make it sound like there was an alternative, which at least at design-time, there wasn't. On top of that, other vendors have pretty much the same problems. Take Intel's stuff for example. It doesn't work without a BSP and you can't even boot a system and have it on for over 30 minutes without a running Management Engine. Qualcomm, AllWinner, Marvell, Ti, they all make ARM SoC's and they all need their own BSP's t…

No, Broadcom is quite unique in requiring blobs to boot. There are plenty of SoCs that are functional without firmware blobs. Generally there are issues getting the GPU working well without firmware blobs but other aspects work fine. Check out the Freescale part used in Bunnie's Novena laptop for example. This is also the case for TI parts and the other manufacturers you list. Broadcom is somewhat unique in requiring…

>No, Broadcom is quite unique in requiring blobs to boot.

Yes precisely, so we offer an alternative to those blobs that allows you to boot ARM without needing a closed-source firmware.

Re: Blobless Linux on Raspberry Pi

#23
post #2

Sadists. The Pi's choice of picking one of the most egregiously unsupported and anti-open source CPU cores was absurd. The people doing the absurdly hard work of taking up the slack that the Raspberry Pi Foundation created from this pick AND the RPI Foundations complete unconcern about the situation and open source at large is to me beyond belief. For a thing that purported to be an educational platform, this situati…

>unlocking the unique video core to get anywhere near there We actually have documented most vector instructions of VC4 and Julian's toolchain supports pretty much all documented ones, so the toolchain we have is pretty close to what Broadcom would have with their MetaWare compiler for VC4. >The RPI3 is rated for 24GFLOPS You mean the VPU, we also have QPU and ARM on the side. >so many really weird abnormal subsystem…

With this bootcode.bin running on the VPU, after the ARM starts up and Linux is loaded, does the VPU halt and remain unreachable, or does the "normal" VC4 RTOS execute such that stuff from the ARM can be mailboxed to it?

Re: Blobless Linux on Raspberry Pi

#24
post #2

Sadists. The Pi's choice of picking one of the most egregiously unsupported and anti-open source CPU cores was absurd. The people doing the absurdly hard work of taking up the slack that the Raspberry Pi Foundation created from this pick AND the RPI Foundations complete unconcern about the situation and open source at large is to me beyond belief. For a thing that purported to be an educational platform, this situati…

The founder and CEO of RPi was a technical director and ASIC architect at Broadcom.

Looking at it like that, its dead obvious why they went with broadcom.

Re: Blobless Linux on Raspberry Pi

#25
post #23

Earlier quoted context omitted.

>unlocking the unique video core to get anywhere near there We actually have documented most vector instructions of VC4 and Julian's toolchain supports pretty much all documented ones, so the toolchain we have is pretty close to what Broadcom would have with their MetaWare compiler for VC4. >The RPI3 is rated for 24GFLOPS You mean the VPU, we also have QPU and ARM on the side. >so many really weird abnormal subsystem…

With this bootcode.bin running on the VPU, after the ARM starts up and Linux is loaded, does the VPU halt and remain unreachable, or does the "normal" VC4 RTOS execute such that stuff from the ARM can be mailboxed to it?

Currently it sleeps and waits for a mailbox interrupt after which it acks it and goes back to sleep. We're planning on using the interface to load a second stage firmware that would emulate the closed source firmware's power/clock management interfaces (but not framebuffer/PV/HVS/HDMI related stuff since there are Linux drivers for that now).

Re: Blobless Linux on Raspberry Pi

#26
post #19

I confess. I'm completely ignorant about the Raspberry Pi even though I have a 3rd generation I bought recently. So I don't really understand what the significance of "Blobless Linux" is. Is the Raspberry Pi an open-source software and hardware platform? If not, what is? What should I have bought if not the Pi3?

> Is the Raspberry Pi an open-source software and hardware platform?

No, the hardware isn't open, and not all of the software is, either. It requires a closed-source blob of code to boot the system. There's "real" firmware in the VC4 chip, which is the first part of the Pi to come up, some binary blob bootloader files, and drivers handling graphics and hardware decoding that are still closed. There is an open-source 3D driver, but it's missing some capabilities from the closed one (hardware accelerated video decoding), but includes some extras (some degree of support for non-mobile OpenGL).

The chips from most other vendors are at least bootable without blobs, even if video output won't be properly accelerated.

Re: Blobless Linux on Raspberry Pi

#27
post #19

I confess. I'm completely ignorant about the Raspberry Pi even though I have a 3rd generation I bought recently. So I don't really understand what the significance of "Blobless Linux" is. Is the Raspberry Pi an open-source software and hardware platform? If not, what is? What should I have bought if not the Pi3?

> Is the Raspberry Pi an open-source software and hardware platform? No, the hardware isn't open, and not all of the software is, either. It requires a closed-source blob of code to boot the system. There's "real" firmware in the VC4 chip, which is the first part of the Pi to come up, some binary blob bootloader files, and drivers handling graphics and hardware decoding that are still closed. There is an open-source…

>drivers handling graphics

Actually that's open and mainlined now, there are DRM drivers for BCM285x family but they rely on mailbox interfaces for power and clock management.

Re: Blobless Linux on Raspberry Pi

#28
post #5
post #2

Sadists. The Pi's choice of picking one of the most egregiously unsupported and anti-open source CPU cores was absurd. The people doing the absurdly hard work of taking up the slack that the Raspberry Pi Foundation created from this pick AND the RPI Foundations complete unconcern about the situation and open source at large is to me beyond belief. For a thing that purported to be an educational platform, this situati…

Are there SoCs at a comparable price/speed that are more open? I can understand being disappointed at this choice, but if no other options exist, then either you're sacrificing price or performance to get more open-ness. My impression has been that this has mostly been about giving a cheap, easy to use software platform, and they've succeeded at that because of the price/performance balance. That was then, though. No…

The Orange Pi PC is $15, roughly comparable to the Pi 3 performance wise, and doesn't require any of this hilarity to boot with open source code.

Re: Blobless Linux on Raspberry Pi

#29

Earlier quoted context omitted.

AllWinner comes to mind; here's one of the more well-known RPi-ish boards using them: https://www.olimex.com/Products/OLinuXino/open-source-hardwa...

Allwinner's been known to play hard and fast with the GPL and LGPL, so I'm not sure I'd cite them for being better about open source. cf. http://linux-sunxi.org/GPL_Violations

I think they got their act together a while ago. More importantly, part of the reason they got in so much hot water is they didn't use the Pi's GPL compliance technique of moving everything interesting into a blob running on a totally undocumented core. Everything important runs on the ARM core. (I believe some of the newer SoCs have an embedded core for power management, but apparently it's OpenRISC-based.)

Re: Blobless Linux on Raspberry Pi

#30
post #5

Earlier quoted context omitted.

Are there SoCs at a comparable price/speed that are more open? I can understand being disappointed at this choice, but if no other options exist, then either you're sacrificing price or performance to get more open-ness. My impression has been that this has mostly been about giving a cheap, easy to use software platform, and they've succeeded at that because of the price/performance balance. That was then, though. No…

"My impression has been that this has mostly been about giving a cheap, easy to use software platform, and they've succeeded at that because of the price/performance balance." It was chosen mainly for the low price. The performance was a little subpar but it had the advantage of a decent video graphics block. "Now that this platform is more established, I imagine they can apply some pressure to get things like the vi…

I doubt the pi foundation are remotely concerned with how open the soc is as it has absolutely no impact on the core uses of the pi. They're smart people and would have made a different choice were it the case.
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