CONFIG_APIC_TIMER_TSC

Use invariant TSC for sys_clock_cycle_get_32()

Type: bool

Help

If your CPU supports invariant TSC, and you know the ratio of the
TSC frequency to CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC (the local APIC
timer frequency), then enable this for a much faster and more
accurate sys_clock_cycle_get_32().

Direct dependencies

(APIC_TIMER && SOC_APOLLO_LAKE) || (APIC_TIMER && SOC_APOLLO_LAKE) || APIC_TIMER

(Includes any dependencies from ifs and menus.)

Defaults

• y

• y

Kconfig definitions

At <Zephyr SoC>/x86/apollo_lake/Kconfig.defconfig:20

Included via Kconfig:8 → Kconfig.zephyr:25 → <BuildDir>/kconfig/Kconfig.soc.defconfig:1

Menu path: (Top)

config APIC_TIMER_TSC
    bool
    default y
    depends on APIC_TIMER && SOC_APOLLO_LAKE

---

At <Zephyr SoC>/x86/apollo_lake/Kconfig.defconfig:20

Included via Kconfig:8 → Kconfig.zephyr:27

Menu path: (Top)

config APIC_TIMER_TSC
    bool
    default y
    depends on APIC_TIMER && SOC_APOLLO_LAKE

---

At <Zephyr Driver>/timer/Kconfig:35

Included via Kconfig:8 → Kconfig.zephyr:42 → <Zephyr Driver>/Kconfig:30

Menu path: (Top) → Device Drivers → Timer Drivers → New local APIC timer

config APIC_TIMER_TSC
    bool "Use invariant TSC for sys_clock_cycle_get_32()"
    depends on APIC_TIMER
    help
      If your CPU supports invariant TSC, and you know the ratio of the
      TSC frequency to CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC (the local APIC
      timer frequency), then enable this for a much faster and more
      accurate sys_clock_cycle_get_32().

(The ‘depends on’ condition includes propagated dependencies from ifs and menus.)