PiZero Roadmap

[gregeric]

Be great if USB BOOT was actually already in the BCM2835 SoC of the ZERO

Not in any Zero made thus far (all 2835C1 variants according to Eben, and I can confirm same from dumps).

There must be some other trick to USB & PXE boot - GPIO pull or boot pin pull? Not had a sniff of things being loaded from network or mass storage when I've tried.

[eupton]

Be great if USB BOOT was actually already in the BCM2835 SoC of the ZERO

No dice, I'm afraid.

It's a straightforward technical operation: the underlying bootrom memory macro itself is common across all three chips and only the programming metal is different. However, in the words of Mr Burke, there is a "substantial dollar value" associated with making the change. As we make more Zeros, it may become easier to make the case for a BCM2835C2, but we're not there yet.

[echmain]

Sorry if this is a silly question...but what's the advantage of booting from USB vs micro sd card?

[Koeshi]

Sorry if this is a silly question...but what's the advantage of booting from USB vs micro sd card?

I'd say the main advantage is giving people more options. Especially for those that want to boot multiple OSes.

[gregeric]

Hi Eben - could you please explain the mechanism/meaning of "bootrom memory macro" above? And "custom hardened" when you were describing the 2837 in the blog post?

So no 2835C2... at least the embedded unicorn & 4GB RAM theories live on

[W. H. Heydt]

That is true for the Pi 3. On the Pi Zero, the bootROM in the BCM2835 needs updating, which is a revision to the chip. Possible, but we are all guessing about whether that is the one. It would have the side effect of bringing the booting of A+ and B+ into line with the Pi 3. The Pi 2 would need an equivalent change to its bootROM -- still possible, but less likely. (I guess that having made the change for the 2837 it is comparatively risk-free to port it to the others. And note Eben mentioned the chip revision numbers for all three -- or was that smoke and mirrors?)

The BOOTROM is in the VC4 VPU, which is common to all RPi SoC's, therefore it "could" be implemented in all future SoC Manufacturing.....

...but it may already be implemented in BCM2835 & BCM2836 SoC's manufactured after August 2015, as well as the BCM2837 ??


Unfortunately it can not be retrospectively implemented, so any new Firmware would need to check for the BOOTROM capabilities !!


Be great if USB BOOT was actually already in the BCM2835 SoC of the ZERO

I am going to stick my neck out and say: No. Not going to happen.

Yes, all three SoCs use the VC4. And Yes, all three SoCs have bootrom code. *However*, changing each of the other two SoCs would mean testing the code in simulation, making new masks, doing a test run of at least one wafer, verifying that the code worked correctly (or, at least, didn't prevent normal operation), going forward using the new masks.

Somebody would have to pay for the work to bring the older SoCs up to the same software level. Who is going to put up the money to do that for older designs?

[plugwash]

CSI or DSI connector would be very popular features, but they are left of for good PCB layout reasons.
Unless RPF has worked miracles on the CAD

Or alternatively worked miracles on the supply chain.

What is hard in 6 layer would be easy in 8.

[plugwash]

Hi Eben - could you please explain the mechanism/meaning of "bootrom memory macro" above?

I would interpret it as the boot rom is a mask rom. That is there is a "macro" (a peice of layout that is placed in the design) which implements a generic rom and then a single metal layer defines what the content of that rom will be.

And "custom hardened" when you were describing the 2837 in the blog post?

As I understand it it means that the arm gate level design was converted to a silicon layout specifically for the chip rather than being bought in as a hard macro.

This would allow it to be tailored for the exact silicon process the BCM283x series uses and to the desired power verses speed compromise.

[MarkHaysHarris777]

Sorry if this is a silly question...but what's the advantage of booting from USB vs micro sd card?

I'd say the main advantage is giving people more options. Especially for those that want to boot multiple OSes.

There are several key advantages: 1) you don't have to buy an SD card, 2) the PI would boot more like a regular PC, and folks are comfortable with that, 3) boot-up would be faster, 4) dual boot would be easier, 5) we wouldn't have all of the goofy boot-up anomalies customary with the SD card boot-up process.

Yes, better options; beyond that a more reliable system.

[fruitoftheloom]

Be great if USB BOOT was actually already in the BCM2835 SoC of the ZERO

No dice, I'm afraid.

It's a straightforward technical operation: the underlying bootrom memory macro itself is common across all three chips and only the programming metal is different. However, in the words of Mr Burke, there is a "substantial dollar value" associated with making the change. As we make more Zeros, it may become easier to make the case for a BCM2835C2, but we're not there yet.

Thank you for the openess of your responses, have learnt a little more

[ali1234]

Will the USB test points be in the same place?

[kernelcode]

LiPo charger?

Cheap, fairly non-invasive, two/three extra pads for a battery

[Cancelor]

Thank you for the openess of your responses, have learnt a little more

Yeh, process of elimination ... it's not USB boot, it's not wifi ....

[seb_ly]

My prediction is analog audio headers / pads - very cheap components!

[fruitoftheloom]

My prediction is analog audio headers / pads - very cheap components!

Composite Out ??

[darkbibble]

analoge audio is already accessable by re-assigning 2 pins, and building a small resistor capacitor cuircuit

[RaTTuS]

My prediction is analog audio headers / pads - very cheap components!

Composite Out ??

is already there as a header

[fruitoftheloom]

My prediction is analog audio headers / pads - very cheap components!

Composite Out ??

is already there as a header

Yeah should of stated an actual Socket installed, more convenient than soldering for beginners...

[SteveSmythe]

ADC ->analogue inputs?

[psiwek]

A quick update.

Raspberry PI Zero production is restarting in Wales next Monday after a hiatus to allow us to focus on Raspberry Pi 3 (a million units built and counting ). We have placed 250ku of new orders, and are aiming to produce at least 50ku/month for the rest of this year. Distribution will continue to be via Pimoroni, Pi Hut, Adafruit and Micro Center for now.

To thank you for your patience, we've taken advantage of the hiatus to add a (much requested) new feature. I'll leave you all to guess what it is (it's not WiFi).

Probability Camera Connector !

[paulweakley]

I don't see any suggestions that it's BLE that they are adding to the Zero. The biggest complaint would be that adding USB components requires a splitter or a powered USB hub. Plus, the question was posed stating that it wasn't WiFi which was the major update to the Pi3 along with BLE. So it's most likely that or another microUSB port for the zero.

[lashturner]

Probably a 1.2ghz quad core would be nice and more ram. Also they should be able to use larger Microsd or allow that new 314gb hard drive.

A quick update.

Raspberry PI Zero production is restarting in Wales next Monday after a hiatus to allow us to focus on Raspberry Pi 3 (a million units built and counting ). We have placed 250ku of new orders, and are aiming to produce at least 50ku/month for the rest of this year. Distribution will continue to be via Pimoroni, Pi Hut, Adafruit and Micro Center for now.

To thank you for your patience, we've taken advantage of the hiatus to add a (much requested) new feature. I'll leave you all to guess what it is (it's not WiFi).

[Gordon2]

I really don't see the purpose in keeping this secret. The device is going to production. Its apparent that the decision is final, so why not tell us what it is? I hope the foundation is not doing this just for some cheesy marketing reason. I thought they were above such tactics.

[dliloch]

Real time clock?

[W. H. Heydt]

Real time clock?

Extremely unlikely...but I'd LOVE to see on the Pi Zero. It would make one of my Pi Zero projects trivially easy.