I'm running Armbian for the SOM204-A20:
"Welcome to ARMBIAN 5.41 user-built Debian GNU/Linux 9 (stretch) 4.14.84-sunxi"
I'm unable to get the second core of the A20 online:
# cat /proc/cpuinfo
processor : 0
model name : ARMv7 Processor rev 4 (v7l)
BogoMIPS : 16.42
Features : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm
CPU implementer : 0x41
CPU architecture: 7
CPU variant : 0x0
CPU part : 0xc07
CPU revision : 4
Hardware : Allwinner sun7i (A20) Family
Revision : 0000
Serial : 165166d502416a4f
terminal++@olimex:/opt
#
This is backed up by checking the CPU reset registers. The second one is being held in reset (Register 0x01C25C80 (CPU1_RST_CTRL)), per the A20 user manual section 1.4.2:
# devmem2 0x01C25C40
Value at address 0x01C25C40: 0x00000003
terminal++@olimex:/opt
# devmem2 0x01C25C80
Value at address 0x01C25C80: 0x00000000
terminal++@olimex:/opt
#
Do I just have a problem with my install? I'd appreciate any pointers as to what might be causing this.
Best Regards,
Jon Fether
Can you also test with our Armbian-based stretch image from here: ftp://staging.olimex.com/Allwinner_Images/A20-OLinuXino/1.latest_mainline_images/stretch/images/ ? Are the results the same?
I took a look at the kernel debs in there. They broke my device tree overlays (Missing /__symbols__ node, DT not compiled with dtc -@). But this wasn't what was requested.
I consulted with some colleagues and they have not encountered the same issue using 4.14.40-sunxi on other A20-SOM204 boards. I'll find a way to synchronize mine up to that. Comparing /proc/config.gz didn't give me a clue.
Thank you for looking into that. Which version of the mainline kernel based Armbian is considered most "stable" for the A20-SOM204 at this time? We're developing a product derived from the A20-SOM204 and want to ensure we are current for security updates, etc at the time of release.
Best Regards,
Jon
Well, the ones we have used in our latest releases seem good enough, we used kernel 5.1.12 next sunxi and Armbian-build 5.89.