d4f5700625
CGo depends on syscall, which (in the standard library) depends on sync, which depends on the runtime. There are also other import cycles. To be able to use the syscall package from upstream, stop using CGo.
85 строки
1,8 КиБ
Go
85 строки
1,8 КиБ
Go
// +build nrf
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package runtime
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import (
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"device/arm"
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"device/nrf"
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)
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func _Cfunc_rtc_sleep(ticks uint32)
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const Microsecond = 1
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func init() {
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initUART()
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initLFCLK()
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initRTC()
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}
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func initUART() {
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nrf.UART0.ENABLE = nrf.UART0_ENABLE_ENABLE_Enabled
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nrf.UART0.BAUDRATE = nrf.UART0_BAUDRATE_BAUDRATE_Baud115200
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nrf.UART0.TASKS_STARTTX = 1
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nrf.UART0.PSELTXD = 6 // pin 6 for NRF52840-DK
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}
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func initLFCLK() {
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nrf.CLOCK.LFCLKSRC = nrf.CLOCK_LFCLKSTAT_SRC_Xtal
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nrf.CLOCK.TASKS_LFCLKSTART = 1
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for nrf.CLOCK.EVENTS_LFCLKSTARTED == 0 {
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}
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nrf.CLOCK.EVENTS_LFCLKSTARTED = 0
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}
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func initRTC() {
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nrf.RTC0.TASKS_START = 1
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// TODO: set priority
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arm.EnableIRQ(nrf.IRQ_RTC0)
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}
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func putchar(c byte) {
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nrf.UART0.TXD = nrf.RegValue(c)
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for nrf.UART0.EVENTS_TXDRDY == 0 {
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}
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nrf.UART0.EVENTS_TXDRDY = 0
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}
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func sleep(d Duration) {
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ticks64 := d / 32
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for ticks64 != 0 {
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monotime() // update timestamp
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ticks := uint32(ticks64) & 0x7fffff // 23 bits (to be on the safe side)
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_Cfunc_rtc_sleep(ticks) // TODO: not accurate (must be d / 30.5175...)
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ticks64 -= Duration(ticks)
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}
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}
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var (
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timestamp uint64 // microseconds since boottime
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rtcLastCounter uint32 // 24 bits ticks
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)
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// Monotonically increasing numer of microseconds since start.
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//
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// Note: very long pauses between measurements (more than 8 minutes) may
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// overflow the counter, leading to incorrect results. This might be fixed by
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// handling the overflow event.
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func monotime() uint64 {
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rtcCounter := uint32(nrf.RTC0.COUNTER)
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offset := (rtcCounter - rtcLastCounter) % 0xffffff // change since last measurement
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rtcLastCounter = rtcCounter
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timestamp += uint64(offset * 32) // TODO: not precise
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return timestamp
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}
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func abort() {
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for {
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arm.Asm("wfi")
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}
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}
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// Align on word boundary.
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func align(ptr uintptr) uintptr {
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return (ptr + 3) &^ 3
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}
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