dpotop
Posts: 78
Joined: Mon Nov 24, 2014 2:14 pm

Boot changes on Raspberry Pi 1 B+ ?

Sun Oct 06, 2019 8:53 am

Hello,

I'm teaching using Raspberry Pi 1 B+ cards and bare metal software.

I've just got a new batch of Raspberry Pi B+ cards, which should be
identical to those I already have. At least, they have the same markings:
B+, V1.2, 2014.

However, they will NOT boot using the same SW I use on the
old ones. Note that I trace the boot process using an UART cable.

At first, I thought it's an SD card compatibility issue - I already
had some of those. My RPI cards would run with my SD cards,
while the NOOBS SD card would run in both my RPI and the new
ones.

However, it's not the case.
On the NOOBS SD card I replaced the content of the
"boot" partition with the SW I use from one of my SD cards.
I then used this card to boot both old and new RPIs.
On both RPIs, booting first reaches a login prompt (recall I trace
through UART).
But then, on my old RPI, it starts my code which prints some stuff.
On the new one, it dies...

My question : are you aware of boot sequence changes on the RPI 1 B+ ?
If yes, how to work around them to get code executed ?

Best regards,
Dumitru
dpotop

dpotop
Posts: 78
Joined: Mon Nov 24, 2014 2:14 pm

Re: Boot changes on Raspberry Pi 1 B+ ?

Sun Oct 06, 2019 10:08 am

I found a workaround - creating a new SD card based on Raspbian Buster.
But this does not answer my previous question - what changed in the
RPI, while on the outside it's labeled in the same way.
Unsettling, when you use the cards for teaching.

Best,
Dpotop
dpotop

Return to “Bare metal, Assembly language”