MNT Reform

Hardware

root #lspci

0000:00:00.0 PCI bridge: Synopsys, Inc. DWC_usb3 / PCIe bridge (rev 01)
0000:01:00.0 Network controller: Qualcomm Atheros AR928X Wireless Network Adapter (PCI-Express) (rev 01)
0001:00:00.0 PCI bridge: Synopsys, Inc. DWC_usb3 / PCIe bridge (rev 01)
0001:01:00.0 Non-Volatile memory controller: Silicon Motion, Inc. Device 2263 (rev 03)

root #lsusb

Bus 001 Device 006: ID 03eb:2042 Atmel Corp. LUFA Keyboard Demo Application
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 005: ID 03eb:2041 Atmel Corp. LUFA Mouse Demo Application
Bus 001 Device 002: ID 0451:8142 Texas Instruments, Inc. TUSB8041 4-Port Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 002: ID 0451:8140 Texas Instruments, Inc. TUSB8041 4-Port Hub
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

root #cat /proc/cpuinfo

processor	: 0
BogoMIPS	: 16.66
Features	: fp asimd evtstrm aes pmull sha1 sha2 crc32 cpuid
CPU implementer	: 0x41
CPU architecture: 8
CPU variant	: 0x0
CPU part	: 0xd03
CPU revision	: 4

processor	: 1
BogoMIPS	: 16.66
Features	: fp asimd evtstrm aes pmull sha1 sha2 crc32 cpuid
CPU implementer	: 0x41
CPU architecture: 8
CPU variant	: 0x0
CPU part	: 0xd03
CPU revision	: 4

processor	: 2
BogoMIPS	: 16.66
Features	: fp asimd evtstrm aes pmull sha1 sha2 crc32 cpuid
CPU implementer	: 0x41
CPU architecture: 8
CPU variant	: 0x0
CPU part	: 0xd03
CPU revision	: 4

processor	: 3
BogoMIPS	: 16.66
Features	: fp asimd evtstrm aes pmull sha1 sha2 crc32 cpuid
CPU implementer	: 0x41
CPU architecture: 8
CPU variant	: 0x0
CPU part	: 0xd03
CPU revision	: 4

f0 respawning

With a default arm64 system, error messages like this will appear both on the default TTY in the system log:

Id "f0" respawning too fast: disabled for 5 minutes

To get rid of those, edit the inittab at /etc/inittab and remove or comment out the last line, that looks something like this:

FILE /etc/inittab

# Architecture specific features
f0:12345:respawn:/sbin/agetty 9600 ttyAMA0 vt100

Then, restart the system.

Clock loses time on reboot

The Reform has two Real-time clocks installed in the system - a battery backed up PCF8523 and an on-CPU SNVS. The SNVS clock is powered by the same rail as the i.MX8M CPU and will reset together with the system. By default, the hwclock is using /dev/rtc0, which might be the wrong clock.

To fix this issue, either remove the rtc-snvs kernel driver, or edit the following line in /etc/conf.d/hwclock

FILE /etc/conf.d/hwclock

clock_args="--rtc /dev/rtc1"

Check which RTC has been assigned to which device by looking at the kernel ring buffer:

user $ dmesg | grep --ignore-case rtc

[    3.556883] rtc-pcf8523 2-0068: registered as rtc0
[    3.563641] rtc-pcf8523 2-0068: setting system clock to 2020-07-13T17:27:26 UTC (1594661246)

In the above example, the PCF8523 is the only RTC and it is assigned to /dev/rtc0.