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:
/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
/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.
Boot from (internal) eMMC using initrd
At some point you will probably want to be able to start the laptop without having an SD card inserted. Also, if you are booting from an encrypted disk, which really you should, you will need a mechanism to open the disk at startup. This chapter will explain how you can achieve both of these goals.