Can Raspberrypi boot initially from USB stick

It doesn't need a battery because it has to be plugged into a power source all the time......... so it will never forget anything - just like me - HA !

(in a normal PC if the battery runs out the BIOS still works - it just has to be reset on bootup)

It would in theory be possible to write a program on the SD card that loaded a USB driver, then loaded and run a program from that.  Essentially the BIOS would be on the SD card.

Maybe someone will do so, it's early days in the life of this product.  But I'm not sure what it would achieve, the system can be written to an SD card just as easily as to a USB drive.

Chris

Or, to put it another way, the RasPi BIOS is in the SD card.  You want to update the BIOS?  Just write new files to the SD card.  I think BIOS settings are in a file called "config.txt" on the SD card, but I'm not sure and haven't looked at details.

I think that the point of being able to boot from a USB device is that it gives the option of installing other operating systems to experiment with, which could install AND run from the USB device so it gets around the space limitations of the SD card.

I remember a problem with the first netbooks that came out with only small solid state hard drives. As soon as the computer connected to the internet and "updated" the operating system the drive was full [of course that was bloatware windows)

Booting from USB would require changes to the initialisation of the BCM2835 during manufacture of the boards.  It is theroretically possible but complicated by the presence of the LAN9512 on the model B. Given that booting from SD card is relatively easy it's not on our development plan.

Even preparing a bootable SD card doesn't appear to be quite as easy as I thought it might be, and was covered by Eben in his webinar yesterday. I am sure an official version of the relevant slides will be available soon, although a 'hacked' version is already available for download from http://stevenicklin.com/images/webex.zip -  thank you SN for that!

As previously mentioned, on startup the Raspberry Pi reads the contents of a config.txt file from the SD card, and a typical example was shown on a later slide.

All good stuff anyway!

David Gibson wrote:

 

I think that the point of being able to boot from a USB device is that it gives the option of installing other operating systems to experiment with, which could install AND run from the USB device so it gets around the space limitations of the SD card.

 

What space limitation is that? SD-cards can be large enough to hold multiple OS's.

The RP-PI has been known to work with SD-Cards with at least 16GB (the Dane-Elec 16Gb class 4) but probably larger cards will also work, (as long as they do not use class 10). See R-PI wiki at http://elinux.org/RPi_VerifiedPeripherals

A typical Linux distro will take about 2GB, so eight of them will fit on a 16Gb card.

It probably won't be long after the R-PI becomes available to the larger public before someone writes a "boot manager", so you can pick which OS (or application) you want to boot from the SD-card.

For me one of the charms of the R-PI is that you can pick and choose an SD-Card, put it in the R-PI, and it will transform the R-PI into the device of your choice. It also harks back to the time of the Amiga 500 (or pick any other home computer) when depending on which floppy (or cartridge) you used you could start some application or Game.

When the R-PI comes in the hands of eager kids, I can see a new activity during school breaks, swapping SD-Cards.

SD-Cards (as long as they do not use class 10)

oh noes!

SD version 3.0 is evil because?

::

http://www.raspberrypi.org/forum/general-discussion/class-10-sd-cards-on-the-production-boards/page-3#p39181

SD version 3.01?  [UHS-I]

http://www.raspberrypi.org/forum/general-discussion/class-10-sd-cards-on-the-production-boards/page-4#p40724

pretty graphs of my benchmark results.  Notice how the Class 10 cards are not so often faster than Class 4 or 6 equivalents in practice.