Identifying which Pi

I am looking for the way to check at boot which Raspberry Pi model my software is running on.
(Pi 1B, 1 B+, etc. I have at least 6 different models)

Is there a SWI I can use?

As a secondary question, is there a SWI which will identify which particular Pi is active (giving the ethernet address, perhaps?)

My search has failed to find the answers :(

What exactly do you need it for? In case you want to know whether your software will run on the current hardware, perhaps it might be better to recognize the CPU architecture (v6, v7, v8) than the RPi model itself? AFAIK you can recognize the ARM type using assembly language and checking which instructions are supported.

Chris Hall’s Screen Help software not only displays information about RISC OS to Monitor matching but also the model of the sytstem it is running on and also the vewrsion of RISC OS running as well.

Is there a SWI I can use?

OS_ReadSysInfo 9 with reason code 7. This should be for all platforms but it did not fully identify an RPi1, it reported Raspberry Pi Unknown.

Chris Hall’s Screen Help software

This is very comprehensive but needs to catchup with the RPi3B+

Line 204 :-
WHEN 13:a6$="Raspberry Pi model 3B+"

See https://www.raspberrypi.org/documentation/hardware/raspberrypi/revision-codes/README.md

OK, Thank You. OS_ReadSysInfo looks good.

What exactly do you need it for?

One issue is to load the correct version of Aemulor for EasySockets and SocketFS.

Chris Hall’s Screen Help software – This is very comprehensive but needs to catchup with the RPi3B+

Now caught up with Pi Zero W, CM3 and model 3B+ (version 1.40 uploaded today to !Store).

Now caught up with Pi Zero W, CM3 and model 3B+ (version 1.40 uploaded today to !Store).

Many thanks. (Just a minor thing, it reports itself as 1.20, as set at the top of the BASIC.)

Now corrected.

Back to my basic problem.

OS_ReadSysInfo 9 with reason code 7.

This correctly identifies a Raspberry Pi 2. But, the problem is, there are two different versions of the Raspberry Pi 2, each with a different processor.

On start-up the system identifies the processor.
For example Cortex_A7 Processor.
Where does that come from? Can I access it?

The kernel doesn’t expose the CPU type, but you can work it out for yourself by reading the CP15 ID register:

DIM code% 16
P%=code%
[ OPT 0
SWI "OS_EnterOS"
MRC CP15,0,R0,C0,C0,0
SWI "OS_LeaveOS"
MOV PC,R14
]
PRINT USR code%

And then decode it to determine the CPU type (check the relevant manuals, or the tables in the kernel sources)

If you’re after more fine-grained information (e.g. “is SWP supported?”) then OS_PlatformFeatures 34 is able to return a whole bunch of info, since checking for specific machine/CPU types is likely to failure as soon as a new machine comes along.

OS_ReadSysInfo 9 with reason code 7.

This correctly identifies a Raspberry Pi 2. But, the problem is, there two different versions of the Raspberry Pi 2, each with a different processor.

Processor type can be found from the Raspberry Pi revision codes

Chris Hall’s !ScrHelp BASIC shows how to read the revision codes. This does not include the processor type, a little bit of hacking is required.

The kernel doesn’t expose the CPU type

except on the screen at boot time! (so I can read it, but my software can’t)

I have not yet got anything useful out of your CP15 example code.

I can read all of the documentation and I can run Chris Hall’s !ScrHelp, but none of that helps me write a simple bit of Basic which tells my software what type of processor is running, so I can load the correct version of Aemulor.

The kernel doesn’t expose the CPU type

But, could it? As it has worked it out and put on the screen.

Perhaps, set a system variable (say, Processor$Type). It would save other software having to repeat the exercise. There are lots of other variables set before the boot sequence is run.

EDIT: I now have your code running at boot time setting Processor$Type for the Raspberry Pi boards which I have. Thank you.

I have not yet got anything useful out of your CP15 example code.

Try this:

DIM code% 16
P%=code%
[ OPT 0
SWI "OS_EnterOS"
MRC CP15,0,R0,C0,C0,0
SWI "OS_LeaveOS"
MOV PC,R14
]
ID%=USR code%
CASE ID% AND &FFF0 OF
WHEN &B760: PRINT "ARM11"
WHEN &C070: PRINT "A7"
WHEN &D030: PRINT "A53"
OTHERWISE: PRINT "Other"
ENDCASE

The kernel doesn’t expose the CPU type

But, could it? As it has worked it out and put on the screen.

Yes, it could. However ROOL aren’t fans of identifying things using enums, since there’s often no “correct” way for a program to cope with enum values that it doesn’t recognise. Instead they prefer APIs where specific features can be checked for (like OS_PlatformFeatures 34, although that does take things to the extreme a bit). See this thread (look for the bits about OS_ReadSysInfo 8), and this thread, amongst others. So there’s the danger that exposing the CPU type directly could lead programmers into continuing that bad behaviour.

OK, Many thanks for your help.

I now have code which identifies the Processor Type and sets a system variable.

I now also have the correct version of Aemulor starting at boot time.

More info here: https://www.riscosopen.org/forum/forums/11/topics/4015