8b79e82686
Because arm.SVCall1 lets pointers escape, the return value of sd_softdevice_is_enabled (passed as a pointer in a parameter) will escape and thus this value will be heap allocated. Use a global variable for this purpose instead to avoid the heap allocation. This is safe as waitForEvent may only be called outside of interrupts.
42 строки
1,2 КиБ
Go
42 строки
1,2 КиБ
Go
// +build nrf,softdevice
|
|
|
|
package runtime
|
|
|
|
import (
|
|
"device/arm"
|
|
"device/nrf"
|
|
)
|
|
|
|
//export sd_app_evt_wait
|
|
func sd_app_evt_wait()
|
|
|
|
// This is a global variable to avoid a heap allocation in waitForEvents.
|
|
var softdeviceEnabled uint8
|
|
|
|
func waitForEvents() {
|
|
// Call into the SoftDevice to sleep. This is necessary here because a
|
|
// normal wfe will not put the chip in low power mode (it still consumes
|
|
// 500µA-1mA). It is really needed to call sd_app_evt_wait for low power
|
|
// consumption.
|
|
|
|
// First check whether the SoftDevice is enabled. Unfortunately,
|
|
// sd_app_evt_wait cannot be called when the SoftDevice is not enabled.
|
|
arm.SVCall1(0x12, &softdeviceEnabled) // sd_softdevice_is_enabled
|
|
|
|
if softdeviceEnabled != 0 {
|
|
// Now pick the appropriate SVCall number. Hopefully they won't change
|
|
// in the future with a different SoftDevice version.
|
|
if nrf.Device == "nrf51" {
|
|
// sd_app_evt_wait: SOC_SVC_BASE_NOT_AVAILABLE + 29
|
|
arm.SVCall0(0x2B + 29)
|
|
} else if nrf.Device == "nrf52" || nrf.Device == "nrf52840" || nrf.Device == "nrf52833" {
|
|
// sd_app_evt_wait: SOC_SVC_BASE_NOT_AVAILABLE + 21
|
|
arm.SVCall0(0x2C + 21)
|
|
} else {
|
|
sd_app_evt_wait()
|
|
}
|
|
} else {
|
|
// SoftDevice is disabled so we can sleep normally.
|
|
arm.Asm("wfe")
|
|
}
|
|
}
|