Raspberry Pi 4

could anyone help me to write a step by step tutorial for noobs.

golden goal is Raspberry pi > MESA 7i90 via SPI (7i90 has already SPI Firmware)

my backgroud is tooldesigner and im a linuxcnc hobbyist.

What i know so far:

1. grab an raspi -image
www.raspberrypi.org/downloads/raspbian/

2. install Preempt-RT kernel
github.com/lemariva/RT-Tools-RPi

3a. install linuxcnc
here it already gets problematic
wiki.linuxcnc.org/cgi-bin/wiki.pl?RaspberryPi
is not working anymore

3b. install linuxcnc form source
github.com/LinuxCNC/linuxcnc
here it would be great to have some steps by steps

4. install mesaflash to check connection:
github.com/micges/mesaflash
sudo mesaflash --device 7i90 --spi --addr /dev/spidev0.0 --readhmid

output should be alike:

Configuration Name: HOSTMOT2

General configuration information:

BoardName : MESA7I90
FPGA Size: 9 KGates
FPGA Pins: 144
Number of IO Ports: 3
Width of one I/O port: 24
Clock Low frequency: 100.0000 MHz
Clock High frequency: 200.0000 MHz
IDROM Type: 3
Instance Stride 0: 4
Instance Stride 1: 64
Register Stride 0: 256
Register Stride 1: 256

Modules in configuration:

Module: WatchDog
There are 1 of WatchDog in configuration
Version: 0
Registers: 3
BaseAddress: 0C00
ClockFrequency: 100.000 MHz
Register Stride: 256 bytes
Instance Stride: 4 bytes

and so on
....

5. then install modified hm2_rpspi.c & spi_common_rpspi.h:
forum.linuxcnc.org/18-computer/36879-ras...pi-4?start=60#141371

6. check connection form hostmot2
halrun -I

within halcmd:
loadrt hostmot2
loadrt hm2_rpspi

and it should print out the config of 7i90

this guide is not complete and i'd like to make it seamless for people like me. could you please help me.

thx

creisey wrote: 3b. install linuxcnc form source
github.com/LinuxCNC/linuxcnc
here it would be great to have some steps by steps

There are LinuxCNC build instructions here linuxcnc.org/docs/devel/html/code/building-linuxcnc.html

Have you seen or tried this
gnipsel.com/linuxcnc/uspace/rpi4-rt.html

not yet, sounds promissing.

im very curious of the parts after the installation of lcnc.

is my part 5 correct?

with halcompile --compile and the hm2_rpspi.c & spi_common_rpspi.h

Rpi aren’t my thing.
One thing I do know of is that one of the guys on the mailing lists is putting together pre made images for the Rpi.
You’d have to join the mailing lists, links are under community on the linuxcnc home page.

creisey wrote: not yet, sounds promissing.

im very curious of the parts after the installation of lcnc.

is my part 5 correct?

with halcompile --compile and the hm2_rpspi.c & spi_common_rpspi.h

No, the drivers are compiled as part of LinuxCNC
(though I suggest using LinuxCNC 2.9 as it has the latest RPI4 support)