VOID
ArmCpuSetup (
IN UINTN MpId
)
{
// Note: System Counter frequency can only be set in Secure privileged mode,
// if security extensions are implemented.
ArmArchTimerSetTimerFreq (PcdGet32 (PcdArmArchTimerFreqInHz));
}
RETURN_STATUS
EFIAPI
TimerConstructor (
VOID
)
{
// Check if the ARM Generic Timer Extension is implemented
if (ArmIsArchTimerImplemented ()) {
UINTN TimerFreq;
// Check if Architectural Timer frequency is valid number (should not be 0)
ASSERT (PcdGet32 (PcdArmArchTimerFreqInHz));
// Check if ticks/uS is not 0. The Architectural timer runs at constant
// frequency irrespective of CPU frequency. According to General Timer Ref
// manual lower bound of the frequency is in the range of 1-10MHz
ASSERT (TICKS_PER_MICRO_SEC);
#ifdef MDE_CPU_ARM
// Only set the frequency for ARMv7. We expect the secure firmware to have already do it
// If the security extensions are not implemented set Timer Frequency
if ((ArmReadIdPfr1 () & ARM_PFR1_SEC) == 0x0) {
ArmArchTimerSetTimerFreq (PcdGet32 (PcdArmArchTimerFreqInHz));
}
#endif
// Architectural Timer Frequency must be set in the Secure privileged(if secure extensions are supported) mode.
// If the reset value (0) is returned just ASSERT.
TimerFreq = ArmArchTimerGetTimerFreq ();
ASSERT (TimerFreq != 0);
} else {
DEBUG ((EFI_D_ERROR, "ARM Architectural Timer is not available in the CPU, hence this library can not be used.\n"));
ASSERT (0);
}
return RETURN_SUCCESS;
}
