// +build cortexm,qemu

package runtime

// This file implements the Stellaris LM3S6965 Cortex-M3 chip as implemented by
// QEMU.

import (
	"device/arm"
	"runtime/volatile"
	"unsafe"
)

type timeUnit int64

var timestamp timeUnit

func postinit() {}

//export Reset_Handler
func main() {
	preinit()
	run()
	arm.SemihostingCall(arm.SemihostingReportException, arm.SemihostingApplicationExit)
	abort()
}

const asyncScheduler = false

func ticksToNanoseconds(ticks timeUnit) int64 {
	return int64(ticks)
}

func nanosecondsToTicks(ns int64) timeUnit {
	return timeUnit(ns)
}

func sleepTicks(d timeUnit) {
	// TODO: actually sleep here for the given time.
	timestamp += d
}

func ticks() timeUnit {
	return timestamp
}

// UART0 output register.
var stdoutWrite = (*volatile.Register8)(unsafe.Pointer(uintptr(0x4000c000)))

func putchar(c byte) {
	stdoutWrite.Set(uint8(c))
}