Zero One Blog Forum Development

Can you add CD/DVD and Flash emulator?

I am a computer repair technician.
I wish your device could emulate USB-DVD ROM and USB Flash. Selecting an image from the device menu from SD card.
Easy Windows installation, PC diagnostics…

Thank you!

Until there is storage, emulating those would be rather useless. And even if there would be sufficient storage, the speed would be abysmal.

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This could only be useful to unlock your LUKS/Bitlocker partitions. OS ISOs require more space and speed, you could use DriveDroid smartphone app for this.

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I use DriveDroid for this purpose, I would definitely recommend it!
If you don’t have or want to root your phone, P4wnP1 A.L.O.A. on the raspberry pi-zero also supports USB-DVD ROM and USB Flash emulation. You can control it via a mobile friendly website hosted by the pi, however if you want to boot from it you will need to power the pi from a power bank beforehand.

Too bad that they can’t make the flipper-one pi-zero based or it would also support this out of the box.

Why the speed would be abysmal? There aren’t only problem of the sd speed?

Not only. The data still needs to pass through the SoC somehow. Not to mention that in this special use case, it needs to at least slightly emulate the hardware alongside that. To me it then sounds unlikely that a small SoC like this running at a few 10s of MHz can shuffle enough data, especially without any fancy DMA acceleration.

A rule of thumb is roughly one bit per instruction (basically Hz in a RISC architecture)… so MHz becomes Mbps.
Best case. (and that’s in or out)

However, I have to admit that i missed that the STM32 does at least have a proper SD card interface and isn’t limited to SPI speeds. At least that’s something…

So i did a little googling, just to see what other people are saying, and it turns out it’s not great.
There are a lot of mentions out there on the internet about max <1MB/s USB data transfer speeds, with only specialized versions reaching speeds like 7MB/s. That later case does actually match a CD-ROM. I had forgotten how terrible they are by today’s standards. (no that we’ll have that fancy version, but as a super-best-case maximum)

Maybe this is good enough for some?

I still maintain there surely must be much better solutions.

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