[mailto:beagleboard@googlegroups.com] On
Behalf Of John Dammeyer
Sent: May-20-21 5:43 PM
To: beagleboard@googlegroups.com
Subject: RE: [beagleboard] ioctl messages to Beagle SPI port.
The latest version of Buster does this when I look for SPI bus ports. The
older Stretch version doesn't have the 0.0 and 0.1
The latest version of Buster does this when I look for SPI bus ports. The
older Stretch version doesn't have the 0.0 and 0.1 and everything is scaled up
by 1.
On either system the scope doesn't show any activity on the SPI0 pins. No CS,
no CLK no Data Out.
The test program from
@googlegroups.com
Subject: RE: [beagleboard] ioctl messages to Beagle SPI port.
# I can't step the machine code past the ioctl system call
Hi John
What are using to step? It's been a long time but I remember being able to go
as deep as I wanted into the linux OS. The hard part was getting
# I can't step the machine code past the ioctl system call
Hi John
What are using to step? It's been a long time but I remember being able to go
as deep as I wanted into the linux OS. The hard part was getting kernel source
code setup but i had that working requires debugging from linux build
So to add this so the research I did isn't repeated.
The control message breaks down as follows:
Top two bits are the direction. The 'k' (0x6B) identifies the SPI type. The
number of bytes is placed into the 32 bit word with the _IOC_NRSHIFT which in
itself is also a macro all defined in the
