Recently I was updating my comp of course there was a need to make some kernel changes (I switched to Intel i5-4570 ), but most of things went rather smoothly, but I had problems with time during dual boot.
hwclock: Open of /dev/rtc failed: No such file or directory
No usable clock interface found.
hwclock: Cannot access the Hardware Clock via any known method.
Checking kernel settings wasn’t obvious to me, cause dual boot was working previously and I though I moved previous kernel config..
Anyway RTC support was not included in kernel.. now I have:
CONFIG_HPET_EMULATE_RTC=y
CONFIG_RTC_LIB=y
CONFIG_RTC_CLASS=y
CONFIG_RTC_HCTOSYS=y
CONFIG_RTC_SYSTOHC=y
CONFIG_RTC_HCTOSYS_DEVICE=”rtc0″
# RTC interfaces
CONFIG_RTC_INTF_SYSFS=y
CONFIG_RTC_INTF_PROC=y
CONFIG_RTC_INTF_DEV=y
# I2C RTC drivers
# SPI RTC drivers
# Platform RTC drivers
CONFIG_RTC_DRV_CMOS=y
# on-CPU RTC drivers
# HID Sensor RTC drivers
Some of settings may be not needed for you, but that’s my conf.
After recompiling and installing kernel error is gone.