targets: add implementation for Tillitis TKey device (#4631)

* initial implementation for Tillitis TKey device
* add UART implementation for TKey
* add Pin interface implementation for TKey touch sensor
* add RNG interface implementation for TKey
* add helpful machine package functions to return identifiers such as name and version for TKey
* use built-in timer for sleep timing on TKey
* modify UART implementation for TKey to implement Serialer interface
* implement BLAKE2s ROM function call for TKey device
* handle abort by triggering TKey device fault using illegal instruction to halt CPU
* simplify TKey implementation by inheriting from existing riscv32 target
* return error for trying to configure invalid baudrates on UART
* add tkey to builder test
* be very specific for features passed to LLVM for specific config in use for TKey
* handle feedback items from TKey device code review

Signed-off-by: deadprogram <[email protected]>

GNUmakefile

@@ -853,6 +853,8 @@ endif
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=maixbit             examples/blinky1
 	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=tkey                examples/blinky1
+	@$(MD5SUM) test.hex
 ifneq ($(WASM), 0)
 	$(TINYGO) build -size short -o wasm.wasm -target=wasm               examples/wasm/export
 	$(TINYGO) build -size short -o wasm.wasm -target=wasm               examples/wasm/main

builder/builder_test.go

@@ -33,6 +33,7 @@ func TestClangAttributes(t *testing.T) {
 		"k210",
 		"nintendoswitch",
 		"riscv-qemu",
+		"tkey",
 		"wasip1",
 		"wasip2",
 		"wasm",

src/crypto/rand/rand_baremetal.go

@@ -1,4 +1,4 @@
-//go:build nrf || (stm32 && !(stm32f103 || stm32l0x1)) || (sam && atsamd51) || (sam && atsame5x) || esp32c3
+//go:build nrf || (stm32 && !(stm32f103 || stm32l0x1)) || (sam && atsamd51) || (sam && atsame5x) || esp32c3 || tkey
 
 // If you update the above build constraint, you'll probably also need to update
 // src/runtime/rand_hwrng.go.

src/device/tkey/tkey.go

@@ -0,0 +1,139 @@
+//go:build tkey
+
+// Hand written file based on https://github.com/tillitis/tkey-libs/blob/main/include/tkey/tk1_mem.h
+
+package tkey
+
+import (
+	"runtime/volatile"
+	"unsafe"
+)
+
+// Peripherals
+var (
+	TRNG = (*TRNG_Type)(unsafe.Pointer(TK1_MMIO_TRNG_BASE))
+
+	TIMER = (*TIMER_Type)(unsafe.Pointer(TK1_MMIO_TIMER_BASE))
+
+	UDS = (*UDS_Type)(unsafe.Pointer(TK1_MMIO_UDS_BASE))
+
+	UART = (*UART_Type)(unsafe.Pointer(TK1_MMIO_UART_BASE))
+
+	TOUCH = (*TOUCH_Type)(unsafe.Pointer(TK1_MMIO_TOUCH_BASE))
+
+	TK1 = (*TK1_Type)(unsafe.Pointer(TK1_MMIO_TK1_BASE))
+)
+
+// Memory sections
+const (
+	TK1_ROM_BASE uintptr = 0x00000000
+
+	TK1_RAM_BASE uintptr = 0x40000000
+
+	TK1_MMIO_BASE uintptr = 0xc0000000
+
+	TK1_MMIO_TRNG_BASE uintptr = 0xc0000000
+
+	TK1_MMIO_TIMER_BASE uintptr = 0xc1000000
+
+	TK1_MMIO_UDS_BASE uintptr = 0xc2000000
+
+	TK1_MMIO_UART_BASE uintptr = 0xc3000000
+
+	TK1_MMIO_TOUCH_BASE uintptr = 0xc4000000
+
+	TK1_MMIO_FW_RAM_BASE uintptr = 0xd0000000
+
+	TK1_MMIO_TK1_BASE uintptr = 0xff000000
+)
+
+// Memory section sizes
+const (
+	TK1_RAM_SIZE uintptr = 0x20000
+
+	TK1_MMIO_SIZE uintptr = 0x3fffffff
+)
+
+type TRNG_Type struct {
+	_       [36]byte
+	STATUS  volatile.Register32
+	_       [88]byte
+	ENTROPY volatile.Register32
+}
+
+type TIMER_Type struct {
+	_         [32]byte
+	CTRL      volatile.Register32
+	STATUS    volatile.Register32
+	PRESCALER volatile.Register32
+	TIMER     volatile.Register32
+}
+
+type UDS_Type struct {
+	_    [64]byte
+	DATA [8]volatile.Register32
+}
+
+type UART_Type struct {
+	_         [128]byte
+	RX_STATUS volatile.Register32
+	RX_DATA   volatile.Register32
+	RX_BYTES  volatile.Register32
+	_         [116]byte
+	TX_STATUS volatile.Register32
+	TX_DATA   volatile.Register32
+}
+
+type TOUCH_Type struct {
+	_      [36]byte
+	STATUS volatile.Register32
+}
+
+type TK1_Type struct {
+	NAME0         volatile.Register32
+	NAME1         volatile.Register32
+	VERSION       volatile.Register32
+	_             [16]byte
+	SWITCH_APP    volatile.Register32
+	_             [4]byte
+	LED           volatile.Register32
+	GPIO          volatile.Register16
+	APP_ADDR      volatile.Register32
+	APP_SIZE      volatile.Register32
+	BLAKE2S       volatile.Register32
+	_             [72]byte
+	CDI_FIRST     [8]volatile.Register32
+	_             [32]byte
+	UDI_FIRST     [2]volatile.Register32
+	_             [62]byte
+	RAM_ADDR_RAND volatile.Register16
+	_             [2]byte
+	RAM_DATA_RAND volatile.Register16
+	_             [126]byte
+	CPU_MON_CTRL  volatile.Register16
+	_             [2]byte
+	CPU_MON_FIRST volatile.Register32
+	CPU_MON_LAST  volatile.Register32
+	_             [60]byte
+	SYSTEM_RESET  volatile.Register16
+	_             [66]byte
+	SPI_EN        volatile.Register32
+	SPI_XFER      volatile.Register32
+	SPI_DATA      volatile.Register32
+}
+
+const (
+	TK1_MMIO_TIMER_CTRL_START_BIT = 0
+	TK1_MMIO_TIMER_CTRL_STOP_BIT  = 1
+	TK1_MMIO_TIMER_CTRL_START     = 1 << TK1_MMIO_TIMER_CTRL_START_BIT
+	TK1_MMIO_TIMER_CTRL_STOP      = 1 << TK1_MMIO_TIMER_CTRL_STOP_BIT
+
+	TK1_MMIO_TK1_LED_R_BIT = 2
+	TK1_MMIO_TK1_LED_G_BIT = 1
+	TK1_MMIO_TK1_LED_B_BIT = 0
+
+	TK1_MMIO_TK1_GPIO1_BIT = 0
+	TK1_MMIO_TK1_GPIO2_BIT = 1
+	TK1_MMIO_TK1_GPIO3_BIT = 2
+	TK1_MMIO_TK1_GPIO4_BIT = 3
+)

src/machine/machine_tkey.go

@@ -0,0 +1,234 @@
+//go:build tkey
+
+package machine
+
+import (
+	"device/tkey"
+	"errors"
+	"strconv"
+)
+
+const deviceName = "TKey"
+
+// GPIO pins modes are only here to match the Pin interface.
+// The actual configuration is fixed in the hardware.
+const (
+	PinOutput PinMode = iota
+	PinInput
+	PinInputPullup
+	PinInputPulldown
+)
+
+const (
+	LED_BLUE  = Pin(tkey.TK1_MMIO_TK1_LED_B_BIT)
+	LED_GREEN = Pin(tkey.TK1_MMIO_TK1_LED_G_BIT)
+	LED_RED   = Pin(tkey.TK1_MMIO_TK1_LED_R_BIT)
+
+	LED = LED_GREEN
+
+	TKEY_TOUCH = Pin(3) // 3 is unused, but we need a value here to match the Pin interface.
+	BUTTON     = TKEY_TOUCH
+
+	GPIO1 = Pin(tkey.TK1_MMIO_TK1_GPIO1_BIT + 8)
+	GPIO2 = Pin(tkey.TK1_MMIO_TK1_GPIO2_BIT + 8)
+	GPIO3 = Pin(tkey.TK1_MMIO_TK1_GPIO3_BIT + 8)
+	GPIO4 = Pin(tkey.TK1_MMIO_TK1_GPIO4_BIT + 8)
+)
+
+var touchConfig, gpio1Config, gpio2Config PinConfig
+
+// No config needed for TKey, just to match the Pin interface.
+func (p Pin) Configure(config PinConfig) {
+	switch p {
+	case BUTTON:
+		touchConfig = config
+
+		// Clear any pending touch events.
+		tkey.TOUCH.STATUS.Set(0)
+	case GPIO1:
+		gpio1Config = config
+	case GPIO2:
+		gpio2Config = config
+	}
+}
+
+// Set pin to high or low.
+func (p Pin) Set(high bool) {
+	switch p {
+	case LED_BLUE, LED_GREEN, LED_RED:
+		if high {
+			tkey.TK1.LED.SetBits(1 << uint(p))
+		} else {
+			tkey.TK1.LED.ClearBits(1 << uint(p))
+		}
+	case GPIO3, GPIO4:
+		if high {
+			tkey.TK1.GPIO.SetBits(1 << uint(p-8))
+		} else {
+			tkey.TK1.GPIO.ClearBits(1 << uint(p-8))
+		}
+	}
+}
+
+// Get returns the current value of a pin.
+func (p Pin) Get() bool {
+	pushed := false
+	mode := PinInput
+
+	switch p {
+	case BUTTON:
+		mode = touchConfig.Mode
+		if tkey.TOUCH.STATUS.HasBits(1) {
+			tkey.TOUCH.STATUS.Set(0)
+			pushed = true
+		}
+	case GPIO1:
+		mode = gpio1Config.Mode
+		pushed = tkey.TK1.GPIO.HasBits(1 << uint(p-8))
+	case GPIO2:
+		mode = gpio2Config.Mode
+		pushed = tkey.TK1.GPIO.HasBits(1 << uint(p-8))
+	case GPIO3, GPIO4:
+		mode = PinOutput
+		pushed = tkey.TK1.GPIO.HasBits(1 << uint(p-8))
+	case LED_BLUE, LED_GREEN, LED_RED:
+		mode = PinOutput
+		pushed = tkey.TK1.LED.HasBits(1 << uint(p))
+	}
+
+	switch mode {
+	case PinInputPullup:
+		return !pushed
+	case PinInput, PinInputPulldown, PinOutput:
+		return pushed
+	}
+
+	return false
+}
+
+type UART struct {
+	Bus *tkey.UART_Type
+}
+
+var (
+	DefaultUART = UART0
+	UART0       = &_UART0
+	_UART0      = UART{Bus: tkey.UART}
+)
+
+// The TKey UART is fixed at 62500 baud, 8N1.
+func (uart *UART) Configure(config UARTConfig) error {
+	if !(config.BaudRate == 62500 || config.BaudRate == 0) {
+		return errors.New("uart: only 62500 baud rate is supported")
+	}
+
+	return nil
+}
+
+// Write a slice of data bytes to the UART.
+func (uart *UART) Write(data []byte) (n int, err error) {
+	for _, c := range data {
+		if err := uart.WriteByte(c); err != nil {
+			return n, err
+		}
+	}
+	return len(data), nil
+}
+
+// WriteByte writes a byte of data to the UART.
+func (uart *UART) WriteByte(c byte) error {
+	for uart.Bus.TX_STATUS.Get() == 0 {
+	}
+
+	uart.Bus.TX_DATA.Set(uint32(c))
+
+	return nil
+}
+
+// Buffered returns the number of bytes buffered in the UART.
+func (uart *UART) Buffered() int {
+	return int(uart.Bus.RX_BYTES.Get())
+}
+
+// ReadByte reads a byte of data from the UART.
+func (uart *UART) ReadByte() (byte, error) {
+	for uart.Bus.RX_STATUS.Get() == 0 {
+	}
+
+	return byte(uart.Bus.RX_DATA.Get()), nil
+}
+
+// DTR is not available on the TKey.
+func (uart *UART) DTR() bool {
+	return false
+}
+
+// RTS is not available on the TKey.
+func (uart *UART) RTS() bool {
+	return false
+}
+
+// GetRNG returns 32 bits of cryptographically secure random data
+func GetRNG() (uint32, error) {
+	for tkey.TRNG.STATUS.Get() == 0 {
+	}
+
+	return uint32(tkey.TRNG.ENTROPY.Get()), nil
+}
+
+// DesignName returns the FPGA design name.
+func DesignName() (string, string) {
+	n0 := tkey.TK1.NAME0.Get()
+	name0 := string([]byte{byte(n0 >> 24), byte(n0 >> 16), byte(n0 >> 8), byte(n0)})
+	n1 := tkey.TK1.NAME1.Get()
+	name1 := string([]byte{byte(n1 >> 24), byte(n1 >> 16), byte(n1 >> 8), byte(n1)})
+
+	return name0, name1
+}
+
+// DesignVersion returns the FPGA design version.
+func DesignVersion() string {
+	version := tkey.TK1.VERSION.Get()
+
+	return strconv.Itoa(int(version))
+}
+
+// CDI returns 8 words of Compound Device Identifier (CDI) generated and written by the firmware when the application is loaded.
+func CDI() []byte {
+	cdi := make([]byte, 32)
+	for i := 0; i < 8; i++ {
+		c := tkey.TK1.CDI_FIRST[i].Get()
+		cdi[i*4] = byte(c >> 24)
+		cdi[i*4+1] = byte(c >> 16)
+		cdi[i*4+2] = byte(c >> 8)
+		cdi[i*4+3] = byte(c)
+	}
+	return cdi
+}
+
+// UDI returns 2 words of Unique Device Identifier (UDI). Only available in firmware mode.
+func UDI() []byte {
+	udi := make([]byte, 8)
+	for i := 0; i < 2; i++ {
+		c := tkey.TK1.UDI_FIRST[i].Get()
+		udi[i*4] = byte(c >> 24)
+		udi[i*4+1] = byte(c >> 16)
+		udi[i*4+2] = byte(c >> 8)
+		udi[i*4+3] = byte(c)
+	}
+	return udi
+}
+
+// UDS returns 8 words of Unique Device Secret. Part of the FPGA design, changed when provisioning a TKey.
+// Only available in firmware mode. UDS is only readable once per power cycle.
+func UDS() []byte {
+	uds := make([]byte, 32)
+	for i := 0; i < 8; i++ {
+		c := tkey.UDS.DATA[i].Get()
+		uds[i*4] = byte(c >> 24)
+		uds[i*4+1] = byte(c >> 16)
+		uds[i*4+2] = byte(c >> 8)
+		uds[i*4+3] = byte(c)
+	}
+	return uds
+}