Minor oddity when booting from USB instead of SD

[Chris Green]

I have just tried booting my old[ish] 1Gb memoory Pi4 from USB instead
of from a micro-SD card. I just copied the SD card to a USB stick,
plugged the USB and turned on. It works, no hassle at all.

The 'oddity' is that the green activity LED now flickers regularly
once a second, when booting from the SD card it's on for a while to
start with, flickers randomly for a while and then is essentially off
all the time (with tiny flashes occasionally). Booting from the USB
is similar at the start but settles down to quite a long flash of
the green light at what looks like one second intervals.

It *feels* like the USB 3 stick is faster than the SD card but I've
not really checked carefully to see if this is really try.


While I'm about it - what a load of pointless waffle there is about
booting a Pi 4 from USB if you do an internet search. I did a quick
look at some of them, pages of instructions which basically boiled
down to 'write the Pi image file on a USB stick and plug it in'! It
works just the same as an SD image. The only thing that might be of
interest is that you can set the order of looking for the image in the
firmware so that either SD card or USB is checked first.

--
Chris Green
·

[The Natural Philosopher]

On 17/01/2024 11:12, Chris Green wrote:
> I have just tried booting my old[ish] 1Gb memoory Pi4 from USB instead
> of from a micro-SD card. I just copied the SD card to a USB stick,
> plugged the USB and turned on. It works, no hassle at all.
>
> The 'oddity' is that the green activity LED now flickers regularly
> once a second, when booting from the SD card it's on for a while to
> start with, flickers randomly for a while and then is essentially off
> all the time (with tiny flashes occasionally). Booting from the USB
> is similar at the start but settles down to quite a long flash of
> the green light at what looks like one second intervals.
>

Yes. I had the same. That green light is saying 'looking for an SD card'.
There is a way to turn it off.

> It *feels* like the USB 3 stick is faster than the SD card but I've
> not really checked carefully to see if this is really try.
>

Probably is. An SSD is even faster :-)

>
> While I'm about it - what a load of pointless waffle there is about
> booting a Pi 4 from USB if you do an internet search. I did a quick
> look at some of them, pages of instructions which basically boiled
> down to 'write the Pi image file on a USB stick and plug it in'! It
> works just the same as an SD image. The only thing that might be of
> interest is that you can set the order of looking for the image in the
> firmware so that either SD card or USB is checked first.
>

Yup.

It was more complicated in earlier models.

Now it is almost as trivial as an Intel based install

--
How fortunate for governments that the people they administer don't think.

Adolf Hitler

[Theo]

Chris Green <c...@isbd.net> wrote:
> I have just tried booting my old[ish] 1Gb memoory Pi4 from USB instead
> of from a micro-SD card. I just copied the SD card to a USB stick,
> plugged the USB and turned on. It works, no hassle at all.
>
> The 'oddity' is that the green activity LED now flickers regularly
> once a second, when booting from the SD card it's on for a while to
> start with, flickers randomly for a while and then is essentially off
> all the time (with tiny flashes occasionally). Booting from the USB
> is similar at the start but settles down to quite a long flash of
> the green light at what looks like one second intervals.

You can disable the LED from showing disc access if you prefer:
https://www.raspberrypi.com/documentation/computers/configuration.html#power-led-2

> While I'm about it - what a load of pointless waffle there is about
> booting a Pi 4 from USB if you do an internet search. I did a quick
> look at some of them, pages of instructions which basically boiled
> down to 'write the Pi image file on a USB stick and plug it in'! It
> works just the same as an SD image. The only thing that might be of
> interest is that you can set the order of looking for the image in the
> firmware so that either SD card or USB is checked first.

IIRC it didn't work at launch, so people came up with various workarounds.
Then support has gradually got better. The fact there's an EEPROM that
allows upgrading the firmware means that's possible, whereas previous
versions relied on bootloaders on the SD card and USB boot support in the
first-stage ROM bootloader was limited.

Theo

[Björn Lundin]

On 2024-01-17 12:12, Chris Green wrote:
> I have just tried booting my old[ish] 1Gb memoory Pi4 from USB instead
> of from a micro-SD card. I just copied the SD card to a USB stick,
> plugged the USB and turned on. It works, no hassle at all.
>
> The 'oddity' is that the green activity LED now flickers regularly
> once a second, when booting from the SD card it's on for a while to
> start with, flickers randomly for a while and then is essentially off
> all the time (with tiny flashes occasionally). Booting from the USB
> is similar at the start but settles down to quite a long flash of
> the green light at what looks like one second intervals.
>

Others pointed out way to turn it off. Or just plug in an empty SD-card.

>I did a quick
> look at some of them, pages of instructions which basically boiled
> down to 'write the Pi image file on a USB stick and plug it in'!

I did the same, with a pi02W
worked first time


--
/Björn

[Lawrence D'Oliveiro]

On Wed, 17 Jan 2024 11:12:17 +0000, Chris Green wrote:

> ... pages of instructions which basically boiled down to

> 'write the Pi image file on a USB stick and plug it in'! It works just
> the same as an SD image.

Is it because a lot of them are Windows users who haven’t grasped the
simplicity of the “dd” utility?