UEFI: Add support for UEFI time and UEFI events; fix STOP \n -> \r\n conversion (#5549)

* add support for UEFI time and UEFI events; fix STOP \n -> \r\n conversion

* apply EFI timezone offset

src/device/uefi/runtime.go

@@ -0,0 +1,21 @@
+package uefi
+
+import _ "unsafe"
+
+//go:linkname gosched runtime.Gosched
+func gosched()
+
+// WaitForEvent blocks while yielding to the TinyGo scheduler so other
+// goroutines can continue to run.
+func WaitForEvent(event EFI_EVENT) EFI_STATUS {
+	for {
+		status := BS().CheckEvent(event)
+		if status == EFI_SUCCESS {
+			return EFI_SUCCESS
+		}
+		if status != EFI_NOT_READY {
+			return status
+		}
+		gosched()
+	}
+}

src/device/uefi/tables.go

@@ -20,6 +20,10 @@ type EFI_RUNTIME_SERVICES struct {
 	queryVariableInfo    uintptr
 }
 
+func (p *EFI_RUNTIME_SERVICES) GetTime(time *EFI_TIME, capabilities *EFI_TIME_CAPABILITIES) EFI_STATUS {
+	return UefiCall2(p.getTime, uintptr(unsafe.Pointer(time)), uintptr(unsafe.Pointer(capabilities)))
+}
+
 type EFI_BOOT_SERVICES struct {
 	Hdr                       EFI_TABLE_HEADER
 	raiseTPL                  uintptr
@@ -82,6 +86,10 @@ func (p *EFI_BOOT_SERVICES) WaitForEvent(numberOfEvents UINTN, event *EFI_EVENT,
 	return UefiCall3(p.waitForEvent, uintptr(numberOfEvents), uintptr(unsafe.Pointer(event)), uintptr(unsafe.Pointer(index)))
 }
 
+func (p *EFI_BOOT_SERVICES) SignalEvent(event EFI_EVENT) EFI_STATUS {
+	return UefiCall1(p.signalEvent, uintptr(event))
+}
+
 func (p *EFI_BOOT_SERVICES) CloseEvent(event EFI_EVENT) EFI_STATUS {
 	return UefiCall1(p.closeEvent, uintptr(event))
 }

src/device/uefi/time.go

@@ -0,0 +1,104 @@
+package uefi
+
+type EFI_TIME struct {
+	Year       uint16
+	Month      byte
+	Day        byte
+	Hour       byte
+	Minute     byte
+	Second     byte
+	Pad1       byte
+	Nanosecond uint32
+	TimeZone   int16
+	Daylight   byte
+	Pad2       byte
+}
+
+type EFI_TIME_CAPABILITIES struct {
+	Resolution uint32
+	Accuracy   uint32
+	SetsToZero BOOLEAN
+}
+
+func GetTime() (EFI_TIME, EFI_STATUS) {
+	var time EFI_TIME
+	status := ST().RuntimeServices.GetTime(&time, nil)
+	return time, status
+}
+
+func (t *EFI_TIME) GetEpoch() (sec int64, nsec int32) {
+	if t.TimeZone != 0x07FF { // EFI_UNSPECIFIED_TIMEZONE
+		sec -= int64(t.TimeZone) * 60
+	}
+	year := int(t.Year)
+	month := int(t.Month)
+
+	d := daysSinceEpoch(year)
+	d += uint64(daysBefore[month-1])
+	if isLeap(year) && month > 2 {
+		d++
+	}
+	d += uint64(t.Day - 1)
+
+	abs := d * secondsPerDay
+	abs += uint64(uint64(t.Hour)*uint64(secondsPerHour) + uint64(t.Minute)*uint64(secondsPerMinute) + uint64(t.Second))
+
+	sec = int64(abs) + (absoluteToInternal + internalToUnix)
+	nsec = int32(t.Nanosecond)
+	return
+}
+
+const (
+	secondsPerMinute = 60
+	secondsPerHour   = 60 * secondsPerMinute
+	secondsPerDay    = 24 * secondsPerHour
+	daysPer400Years  = 365*400 + 97
+	daysPer100Years  = 365*100 + 24
+	daysPer4Years    = 365*4 + 1
+
+	absoluteZeroYear = -292277022399
+	internalYear     = 1
+
+	absoluteToInternal int64 = (absoluteZeroYear - internalYear) * 365.2425 * secondsPerDay
+	unixToInternal     int64 = (1969*365 + 1969/4 - 1969/100 + 1969/400) * secondsPerDay
+	internalToUnix     int64 = -unixToInternal
+)
+
+var daysBefore = [...]int32{
+	0,
+	31,
+	31 + 28,
+	31 + 28 + 31,
+	31 + 28 + 31 + 30,
+	31 + 28 + 31 + 30 + 31,
+	31 + 28 + 31 + 30 + 31 + 30,
+	31 + 28 + 31 + 30 + 31 + 30 + 31,
+	31 + 28 + 31 + 30 + 31 + 30 + 31 + 31,
+	31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30,
+	31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31,
+	31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31 + 30,
+	31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31 + 30 + 31,
+}
+
+func daysSinceEpoch(year int) uint64 {
+	y := uint64(int64(year) - absoluteZeroYear)
+
+	n := y / 400
+	y -= 400 * n
+	d := daysPer400Years * n
+
+	n = y / 100
+	y -= 100 * n
+	d += daysPer100Years * n
+
+	n = y / 4
+	y -= 4 * n
+	d += daysPer4Years * n
+
+	d += 365 * y
+	return d
+}
+
+func isLeap(year int) bool {
+	return year%4 == 0 && (year%100 != 0 || year%400 == 0)
+}

src/machine/machine_uefi.go

@@ -9,8 +9,10 @@ import (
 const deviceName = "UEFI"
 
 type (
-	EFI_STATUS = deviceuefi.EFI_STATUS
+	EFI_STATUS            = deviceuefi.EFI_STATUS
-	TextOutput = deviceuefi.TextOutput
+	EFI_TIME              = deviceuefi.EFI_TIME
+	EFI_TIME_CAPABILITIES = deviceuefi.EFI_TIME_CAPABILITIES
+	TextOutput            = deviceuefi.TextOutput
 
 	Error = deviceuefi.Error
 )
@@ -88,6 +90,10 @@ var (
 	ErrHTTPError           = deviceuefi.ErrHTTPError
 )
 
+func GetTime() (EFI_TIME, EFI_STATUS) {
+	return deviceuefi.GetTime()
+}
+
 func ConsoleOut() *TextOutput {
 	return deviceuefi.ConsoleOut()
 }

src/runtime/runtime_uefi.go

@@ -56,9 +56,8 @@ func sleepTicks(d timeUnit) {
 
 func putchar(c byte) {
 	if c == '\n' {
-		buf := [4]uefi.CHAR16{'\r', 0, '\n', 0}
+		buf := [2]uefi.CHAR16{uefi.CHAR16('\r'), 0}
 		uefi.ST().ConOut.OutputString(&buf[0])
-		return
 	}
 	buf := [2]uefi.CHAR16{uefi.CHAR16(c), 0}
 	uefi.ST().ConOut.OutputString(&buf[0])
@@ -103,6 +102,15 @@ func growHeap() bool {
 	return false
 }
 
+func init() {
+	mono := nanotime()
+	efiTime, status := uefi.GetTime()
+	if status == uefi.EFI_SUCCESS {
+		sec, nsec := efiTime.GetEpoch()
+		timeOffset.Store(sec*1000000000 + int64(nsec) - mono)
+	}
+}
+
 func SetWaitForEvents(f func()) {
 	waitForEventsFunction = f
 }