Wow. In due time these guys might start actually releasing datasheets to developers who, you know, need to know the register set and API to like, make their chips work. I don't know why the hell these idiots treat their firmware APIs with Manhattan-project style secrecy, but I would highly advise against designing a new product with a broadcom chipset. They are totally asinine.
A birthday present from Broadcom
101–110 of 170 posts
Re: A birthday present from Broadcom
#102Earlier quoted context omitted.
The fashion of the day is, for better or worse, "if you don't have a github you ain't shit."
git is overkill for facilities with small groups working in a common area (not hard to imagine if you're in the hardware biz) and all the engineers are used to cvs command syntax..
The best VCS is the one you use.
Re: A birthday present from Broadcom
#103But we’re incredibly proud that VideoCore IV is the first publicly documented mobile graphics core Wasn't Intel first by virtue of using their in-house "HD Graphics" hardware in Silvermont (Bay Trail-M and -T)? Regardless, this is a huge thing in the ARM world, and I hope other vendors will begin to open up documentation.
Bay Trail-M means "mobile" as in "laptop", not "mobile" as in "smartphone". Intel's smartphone stuff all still using PowerVR, including the upcoming Merrifield which will be using the PowerVR G64x0.
Re: A birthday present from Broadcom
#104Quick noob question...is the Pi still the best/most flexible option for general hardware hacking? What about ARM dev boards from Samsung, Qualcomm etc?
'Best' can measured in a few ways, the RPi has a huge community, and it's certainly a bargain (though you will end up buying a bunch of odds and ends to get going). The Beaglebone Black is probably the other major contender, way more GPIO pins, can boot from the onboard memory, is ARMv7, for $10 more.
BeagleBone Black has just one USB port, which is often very inconvenient. For example, if you want to run Octoprint accessible via WiFi and control a 3d printer, two USB ports will be needed. Certainly, a USB hub is an option, but it makes the setup more brittle (some USB WiFi dongles won't work over some hubs) and more expensive.
Re: A birthday present from Broadcom
#105Earlier quoted context omitted.
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 c…
I did work on it directly. James (now working solely for Pi as HW director), Gordon (now working solely for Pi as SW director) and I (still working for Broadcom, and for Pi) were members of the VideoCore IV design team. James and I were responsible for the QPU (quad processor unit) design and implementation in the V3D block.
There's no one thing about V3D which makes it superior to other cores. Just lots of attention to detail at the design, RTL implementation and layout stages.
Re: A birthday present from Broadcom
#106Earlier quoted context omitted.
Nope (though note, I'm biased for several reasons). In terms of performance per unit area and performance per Watt, VideoCore IV is about as good as you're going to get. There are chips with higher performance GPUs out there, but they get there by brute force: throwing area (and therefore cost) and/or power at the problem.
Waiting for the VideoCore V :) I noticed that the Broadcom LTE offerings such as the M320 do not use VideoCore and instead use PowerVR 5XT. Is it because they were originally Renesas designs? Hoping to see more VideoCore action in the future :)
:)
Re: A birthday present from Broadcom
#107Earlier quoted context omitted.
The fashion of the day is, for better or worse, "if you don't have a github you ain't shit."
git is overkill for facilities with small groups working in a common area (not hard to imagine if you're in the hardware biz) and all the engineers are used to cvs command syntax..
Overkill until the network goes down or the server dies or somebody needs to work remotely and the VPN isn't working. I don't know how fast git is wrt cvs, but I remember being pleasantly surprised coming from svn.
You don't have to have a distributed workflow to occasionally reap the benefits of working with git.
Re: A birthday present from Broadcom
#108Earlier quoted context omitted.
More a moral victory from my PoV. Remember, code that runs in the blob is running on another processor, so not costing you ARM cycles. That's why we've set the Quake fps target much lower than what you can hit with the blob.
Thanks for all the effort to get to this stage Eben. As someone who was repeatedly told (on the RP forums) that I had no business to desire the user-land graphics to be open-sourced, and that only hardware engineers would get any benefit from this code, I thought this day would never come! I'm happy to be proved wrong, and happy that many little 'RasPis' will have an extended lifespan from this decision by your emplo…
Fingers crossed. I'm most excited about the GPGPU stuff people will be able to do now we've documented the instruction set for the QPU. More on this next week.
Re: A birthday present from Broadcom
#109Oh woah - I'm very happy about the BSD license. This means people can more easily potentially spin up business around this platform. I wonder why they chose it... Does anyone have any insight?
BSD-like licenses seem to be the standard for userland graphics libraries. There's a lot of useful stuff in there (for example the shader compiler) that may be of general use elsewhere, and we wanted to make sure people could use it.
The 3-clause BSD is a compromise - we're happy for the stuff to be used but it's nice to get some credit :)
Re: A birthday present from Broadcom
#110Earlier quoted context omitted.
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 { ...…
I made a back of the envelop design of a arch that used the same technique in college. Way cool to see it in practice.
This project of yours look really cool, https://github.com/peterderivaz/pymeta3
What do you think about http://www.myhdl.org/doku.php ?