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A birthday present from Broadcom

raspberrypi.org

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Re: A birthday present from Broadcom

#81

Post by pjc50 »

patrickyeon wrote: post #5

That's really a surprise. Broadcom is cemented in my mind as one of the hardest companies to get even basic datasheets out of. I know the saying is "don't look a gift horse in the mouth", but could it be that their graphics cores are not competitive in pure technical capabilities, so they've decided to compete on open-ness? I'm not really involved in that area of hardware/software.

This is almost certainly driven entirely by Eben Upton, who is the link between Broadcom and Raspberry Pi. He's probably been bundling up the huge list of demands for OSS video drivers and dumping them on the desk of the right person, while wearing down the objectors. It's something that Raspberry Pi have wanted for ages.

Edit: ah, Eben has turned up here himself :)

Re: A birthday present from Broadcom

#82

Post by DougMerritt »

akiselev wrote: post #55
ansimionescu wrote: post #40

Earlier quoted context omitted.

Good ol' gzip download, because fuck source control. edit: FWIW, a friend who works there told me flat-out to just avoid them (I'm job-hunting)

This is almost a universal problem with firmware and chip engineers, who are generally older and more experienced, and thus apparently can't be taught new tricks. There are also issues with bureaucracies in each and every semiconductor company (which are on average decades old) so firmware is usually hot potatoed around by management and ends up lighting the customers' projects on fire almost every damn time. I don't…

> generally older and more experienced, and thus apparently can't be taught new tricks.

Ah yes, experience, the bane of all technical projects.

I have worked at lots of hardware companies over the years, and to varying degrees, they universally treat software as the red headed stepchild -- an unfortunate necessity akin to paying taxes, or worse.

Re: A birthday present from Broadcom

#83

Post by jpwright »

sneak wrote: post #58
dredge wrote: post #29

Earlier quoted context omitted.

(a) They are a charity. (b) They demonstrated the Pi running Quake 3 at a reasonable frame rate in 2011. There's a picture of it in the blog post. (c) The competition rules say "To submit an Entry, and Entrant shall email a link to a public GitHub repository containing the full source code for the Entry..." so just showing the result wouldn't be eligible to win. That and they already know what it looks like, because…

They aren't really a charity; they sell a product from a manufacturer (the Broadcom SoC) and were started by Broadcom employees. So, in a way, this "charity" is really just a marketing subsidiary of Broadcom.

They are a UK-registered charity organization, and the Raspberry Pi is much more than just the Broadcom SoC.

Re: A birthday present from Broadcom

#84

Post by ansible »

sneak wrote: post #58
dredge wrote: post #29

Earlier quoted context omitted.

(a) They are a charity. (b) They demonstrated the Pi running Quake 3 at a reasonable frame rate in 2011. There's a picture of it in the blog post. (c) The competition rules say "To submit an Entry, and Entrant shall email a link to a public GitHub repository containing the full source code for the Entry..." so just showing the result wouldn't be eligible to win. That and they already know what it looks like, because…

They aren't really a charity; they sell a product from a manufacturer (the Broadcom SoC) and were started by Broadcom employees. So, in a way, this "charity" is really just a marketing subsidiary of Broadcom.

Whatever RasPi is, the fact remains that they're selling a relatively open platform at price near production costs. And that platform just got significantly more open.

And they are now offering a bounty for the creation (refinement, really) of more free software. Which will benefit the entire community surrounding the RasPi. So that is good. Even if they were offering $10 USD, there might be someone who'll take up the challenge just to get the bragging rights.

Re: A birthday present from Broadcom

#85

Post by embedded »

akiselev wrote: post #55
ansimionescu wrote: post #40

Earlier quoted context omitted.

Good ol' gzip download, because fuck source control. edit: FWIW, a friend who works there told me flat-out to just avoid them (I'm job-hunting)

This is almost a universal problem with firmware and chip engineers, who are generally older and more experienced, and thus apparently can't be taught new tricks. There are also issues with bureaucracies in each and every semiconductor company (which are on average decades old) so firmware is usually hot potatoed around by management and ends up lighting the customers' projects on fire almost every damn time. I don't…

Wow, armchair engineer, you sound like you really know what you're talking about.

When this old engineer worked on embedded MIPS cores and 802.11[abgn] at Broadcom, everything was under source code control. This was pre-git, so I think we were using cvs. How the hell do you conclude that releasing a zip file means the engineers don't use source code control?

Re: A birthday present from Broadcom

#86

Post by peterderivaz »

gtlk wrote: post #67
ansimionescu wrote: post #40

Earlier quoted context omitted.

Good ol' gzip download, because fuck source control. edit: FWIW, a friend who works there told me flat-out to just avoid them (I'm job-hunting)

Don't worry, they're going to have to release it again. This zip contains many files with copyright (c) Broadcom (and other companies) missing the 3-clause BSD license. On an unrelated note, x86 looks like RISC compared to this chip assembly language :) vmul -,H(1,0),3 CLRA ACC vadd HX(3,0),H(0,0),2 ACC vasr H(0++,0),HX(2++,0),2 REP 2 ;vmov H(0++,0),0 REP 2 vst H(0++,0),(r0+=r3) REP 2 add r0,16 addcmpblt r5,1,r1,loop…

The vector register file is a block of registers 64 bytes across by 64 down which can be accessed horizontally (H) or vertically (V), and in units of 16 bytes (H8), 16 shorts (H16 or HX), or 16 32-bit words (H32).

Each processor has an accumulator that can be cleared (CLRA) or used (ACC).

This code is basically equivalent to the following C code:

    uint8 in[2][16];
    int16 temp[2][16];
    int32 r1,r3,r5;
    uint8 *r0;
    do {
        ... code omitted
	// vmul  -,H(1,0),3 CLRA ACC
	// vadd  HX(3,0),H(0,0),2 ACC
	for(x=0;x>2;
		r0[y*r3+x] = in[y][x];
	  }
	}   
	//   add   r0,16
	//   addcmpblt r5,1,r1,loopacross
	r0 += 16;
	r5 += 1;
    } while (r5
This is code for the vector processor. This is not the same as the GPU cores which use a different architecture and instruction set (based around floating point calculations).

Re: A birthday present from Broadcom

#87

Post by AceJohnny2 »

ebenupton wrote: post #41
AceJohnny2 wrote: post #35

Earlier quoted context omitted.

Two years ago (or whenever the BCM2835 itself came out on the market), sure, but surely things have improved since? We've at least jumped a technology node, and hasn't nVidia improved?

Less than you'd think. Other vendors have improved somewhat, but from often from pretty poor starting points. Jumping a process node is a "brute force" approach: we can all do that. I'm more interested in apples-to-apples comparisons on a given node.

Had you worked on it directly, or were working on other parts of the chip while at Broadcom? I've always been hoping to see some hard benchmarks. I had worked on a video codec IP for a competing (but defunct) chip, hence my curiosity :)

I'm curious about the technological history of the VideoCore. The wikipedia page [1] and Broadcom marketing page [2] don't give a lot of information to distinguish it from competing cores (such as ARM's own Mali or nVidia's Tegra line). In fact, the information I see makes it seems pretty run-of-the-mill tech of 5 years ago.

I guess I could RTFM now that it's available :D

Edit/afterthought: none of this really matters actually, as there is no other chip on the market with the BCM2835's capabilities and that is more open-sourced.

[1] http://en.wikipedia.org/wiki/VideoCore [2] http://www.broadcom.com/products/technology/mobmm_videocore....

Re: A birthday present from Broadcom

#88

Post by Crito »

sneak wrote: post #58
dredge wrote: post #29

Earlier quoted context omitted.

(a) They are a charity. (b) They demonstrated the Pi running Quake 3 at a reasonable frame rate in 2011. There's a picture of it in the blog post. (c) The competition rules say "To submit an Entry, and Entrant shall email a link to a public GitHub repository containing the full source code for the Entry..." so just showing the result wouldn't be eligible to win. That and they already know what it looks like, because…

They aren't really a charity; they sell a product from a manufacturer (the Broadcom SoC) and were started by Broadcom employees. So, in a way, this "charity" is really just a marketing subsidiary of Broadcom.

"The Raspberry Pi Foundation is a UK registered charity (Registration Number 1129409)"

Re: A birthday present from Broadcom

#89

Post by GFK_of_xmaspast »

embedded wrote: post #85
akiselev wrote: post #55

Earlier quoted context omitted.

This is almost a universal problem with firmware and chip engineers, who are generally older and more experienced, and thus apparently can't be taught new tricks. There are also issues with bureaucracies in each and every semiconductor company (which are on average decades old) so firmware is usually hot potatoed around by management and ends up lighting the customers' projects on fire almost every damn time. I don't…

Wow, armchair engineer, you sound like you really know what you're talking about. When this old engineer worked on embedded MIPS cores and 802.11[abgn] at Broadcom, everything was under source code control. This was pre-git, so I think we were using cvs. How the hell do you conclude that releasing a zip file means the engineers don't use source code control?

The fashion of the day is, for better or worse, "if you don't have a github you ain't shit."

Re: A birthday present from Broadcom

#90

Post by Elv13 »

samolang wrote: post #37
tejbirwason wrote: post #25

Proud to have worked on this during my 8-month internship at Broadcom. It remains one of the toughest and rewarding projects to tackle within the company. I am pleasantly surprised to see Broadcom open up like this and release the full documentation. A step in the right direction for a grossly under-rated company.

I've never heard of an 8-month internship. What sort of program is that? Like a semester+summer?

My university (Montreal ETS) also do it. They have 3 (real/full) semesters per years. Students usually take 1 of them per year to work as interns. You can technically work as intern for like 5 years and still be considered enrolled into the engineering program. Students will either prefer 8 months internship for well paid jobs or jobs that cannot be done in a 4 months development cycle(like a video game). In the end, it does increase the total time spent to graduate, but students tend to have much lower debts (if not profit) at the end.

These kind of deals seem to be quite widespread in Canada (just like the above commenter show). I know these private sector teaching organization deals are not well considered in some part of the world, but, in the end, someone who just graduated, but accumulate years of full time working experience have an easier time landing a job at the end, at least for STEM jobs.

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