Booting my Raspberry Pi 4 from a USB system

The firmware included with the Raspberry Pi 2 Model B model 1.2 launched the potential of booting from a USB system: earlier than that, it was solely potential in addition from an SD or microSD card. But that functionality wasn’t extensively identified or used on the Pi 2 or Pi 3.  In my opinion there have been two main causes for this:

• USB boot was not activated by default, and activating it was a bit sophisticated, or at the very least tedious
• The Pi 2 and Pi 3 solely had USB 2.0, which meant that USB gadgets had been even slower than the SD card

The Raspberry Pi 4, nonetheless, has fastened each of these issues. USB boot is enabled by default, and the Pi 4 has two USB 3.0 ports which make USB mass storage gadgets noticeably quicker than SD playing cards. So, in principle, USB boot must be gaining in reputation, nevertheless it appears to me that isn’t taking place. Perhaps it’s due to a scarcity of familiarity with the chance, or a scarcity of detailed examples of doing it. So I’ll run by numerous features and examples of it on this put up.

SEE: Hiring Kit: Python developer (TechRepublic Premium)

The first query to ask, I suppose, can be why is USB boot attention-grabbing in any respect? Well, one good purpose I’ve already talked about is {that a} USB 3.0 system is quicker than an SD card. Another is that USB drives are likely to value lower than microSD playing cards of the identical measurement, and because the storage capability goes up, the worth distinction will get bigger. The purpose I’ve gotten into this, nonetheless, is that I just lately acquired a Raspberry Pi 4 case which incorporates an M.2 SSD adapter, and that drive connects through USB. (I shall be writing about that case in my subsequent put up.)

First, as I simply stated, USB boot is enabled by default on the Pi 4B (and the Pi 400, by the best way), however there’s a small caveat to that. It appears that some early bootloader firmware variations didn’t correctly assist this, so you must ensure that your Raspberry Pi 4 has bootloader eeprom firmware dated Sep 3 2020 or later. There are two methods to do that; both take away the microSD card after which boot, so you’ll be able to learn the firmware date from the diagnostic display, or just run vcgencmd bootloader_version. I’ve three Pi 4 items (with 1GB, 2GB and 4GB of reminiscence) which I acquired from the primary batch accessible in Switzerland, and all of them have Sep 3 firmware so I assume the older firmware isn’t quite common. If you occur to have an older model, the directions for updating are given within the USB mass storage boot part of the Raspberry Pi Hardware Documentation.

The different requirement for USB boot is that you must be booting Raspberry Pi OS model 2020-08-20 or later. In sensible phrases this merely implies that it is best to use the newest Raspberry Pi OS picture from the downloads web page (which at present is 2020-12-02), or if you’re going to copy an present SD card examine the contents of /and so forth/rpi-issue. I’m not going to get right into a dialogue of booting different Linux distributions at this level, as a result of I have not had time to strive it out myself but.

Creating a bootable USB system may be very easy. If you have already got a Raspberry Pi 4 working, you’ll be able to both clone the present SD drive, or you should use the Raspberry Pi Imager to obtain and replica the newest model to the USB drive.

First, and crucial, just be sure you have a USB 3 drive (duh)! You may use a USB 2 system, however you’ll nearly actually not be happy with the efficiency once you booted it. Also, I’d recommend utilizing a “nano” type system as a result of not solely does that look higher, it’s much less prone to be knocked free or broken than having massive previous USB stick hanging off the tip of your Raspberry Pi. Finally, just be sure you have the drive plugged right into a USB 3 port (one of many two which have a blue tab, not a black tab).

Cloning an present SD card is usually a good possibility if you have already got a system setup and configured, with further packages and functions put in. To do that, go to the desktop menu, Accessories, SD Card Copier. The utility will establish any SD and USB drives at present linked, and you’ll select the From/To gadgets appropriately. The utility will attempt to modify for various sizes of drives, however I’d recommend that you simply examine the partitions on the USB system after it has completed to make certain you’re pleased with no matter it did.

The different, making a USB drive with a freshly put in picture, has the benefit of being positive that you’re utilizing the newest distribution launch, and will provide you with extra management and suppleness in partitioning. But the drawback is that you’ll have to undergo the first-time boot course of, together with system configuration, putting in the newest updates, and probably putting in and configuring no matter further packages and functions it’s possible you’ll want or need.

To create a recent drive, you’ll first must obtain the imager (it’s not included within the base PiOS distribution):

    sudo apt set up rpi-imager

Then go to the desktop menu, Accessories, Imager. There are simply a few issues to be careful for on this utility. Most vital, within the Operating System choice the Raspberry Pi OS which comes up in the primary listing is the “basic with desktop” model. If you need the “full” model with the entire beneficial software program put in, or the “Lite” model with solely CLI (no GUI desktop), you must choose that from the listing underneath Raspberry Pi OS (different). The USB disk will present up within the SD Card choice – and it will not provide to overwrite your present SD card, so the USB drive is prone to be the one factor listed there.

The different different for making a bootable USB drive is to do it on one other pc, in just about the identical means that I’ve described making a bootable SD card in earlier posts. Get the picture from the Raspberry Pi Downloads web page, and replica it to the USB drive. There is nothing particular that must be achieved otherwise from the same old SD process.

Once the bootable USB drive has been created, all you should do is shut down the Raspberry Pi 4, take away the microSD card, and plug within the USB drive. When you energy up the Pi 4 once more it ought to boot from USB, and it is best to be capable to inform the distinction in pace each for the boot course of itself, and when beginning packages and functions.

SEE: Raspberry Pi 400: Its designer reveals extra concerning the quicker Pi 4 within the $70 PC’s keyboard

So, that is the essential course of. Based on my expertise to this point, you’ll be able to have an present Raspberry Pi 4 or 400 booting and working from a USB drive in lower than half-hour. Now, for a have a look at a few of the extra enjoyable/attention-grabbing technical bits!

The “official” particulars about USB booting are within the Raspberry Pi Hardware documentation, underneath USB mass storage boot. There is a few further technical element underneath USB as nicely. There can be a web page with some very attention-grabbing particulars particularly concerning the Raspberry Pi 4 bootloader.

The Raspberry Pi 4 (and 400) bootloader firmware truly is aware of learn how to boot from both USB or the Network along with the SD card. The raspi-config utility enables you to make a easy choice between these two as a secondary boot system when an SD card isn’t current. This is a bit odd, as a result of raspi-config is a command-line (CLI) utility, and this choice hasn’t been added to the GUI Raspberry Pi Configuration utility. I’ve to surprise why not, however anyway… to run raspi-config you first begin a terminal window, then run sudo raspi-config, to get the preliminary display proven right here. From this display select Advanced Options after which Boot Order.

In my opinion, the Boot Order display is somewhat poorly named. You cannot truly do a lot with the boot order right here, as a result of the SD card will at all times be tried first, and you’ll solely specify both USB or Network boot to comply with that, however not each. If you are as much as a little bit of command-line work, there are much more potentialities accessible through the rpi-eeprom-config utility, which is described intimately on the Raspberry Pi 4 bootloader web page.

There is another doubtlessly complicated factor about updating the eeprom configuration, utilizing both raspi-config or rpi-eeprom-config, which I need to clarify. 

Any adjustments you make haven’t but been utilized once you save and exit from the utility. They have been saved to the /boot listing on the disk, so you must reboot that disk to ensure that the eeprom to really be up to date. If you do not, for instance, in the event you change the worth however then shut down, take away the SD card and boot from a USB drive, the eeprom is not going to be modified. I do know this feels like an obscure case, nevertheless it bit me whereas I used to be engaged on this, so if/when it bites you, do not forget that I advised you so.