CNTKCTL_EL1
64-bitGenericWhether the generic timer counts, and whether EL0 can read it. Bare-metal code reads this on boot to learn the counter frequency, because the counters themselves do not say how fast they tick.
Field layout
—
1
0
byte 7
byte 6
byte 5
byte 4
byte 3
byte 2
byte 1
byte 0
Current value hover a field to locate it
B7
B6
B5
B4
B3
B2
B1
B0
Fields
| Bits | Field | Bits | Value | Description |
|---|---|---|---|---|
| 63:2 | — | 62 | Not assigned to a documented field. Values written here are reserved and should be treated as read-as-zero unless the architecture says otherwise. | |
| 1 | CCTEN[1:1] | 1 | 0x0 | User-mode access to CNTPCT_EL0. Clear it before entering the kernel if a user program should not be able to read a counter it could use to measure the scheduler. |
| 0 | CRSTEN[0:0] | 1 | 0x0 | Counter reset. Writes only. |