nrf,sam,rp2040: add machine.DeviceID function

GNUmakefile

@@ -506,6 +506,8 @@ smoketest:
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=feather-rp2040      examples/watchdog
 	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=feather-rp2040      examples/device-id
+	@$(MD5SUM) test.hex
 	# test simulated boards on play.tinygo.org
 ifneq ($(WASM), 0)
 	$(TINYGO) build -size short -o test.wasm -tags=arduino              examples/blinky1

src/examples/device-id/main.go

@@ -0,0 +1,21 @@
+package main
+
+import (
+	"encoding/hex"
+	"machine"
+	"time"
+)
+
+func main() {
+	time.Sleep(2 * time.Second)
+
+	// For efficiency, it's best to get the device ID once and cache it
+	// (e.g. on RP2040 XIP flash and interrupts disabled for period of
+	// retrieving the hardware ID from ROM chip)
+	id := machine.DeviceID()
+
+	for {
+		println("Device ID:", hex.EncodeToString(id))
+		time.Sleep(1 * time.Second)
+	}
+}

src/machine/deviceid.go

@@ -0,0 +1,17 @@
+//go:build rp2040 || nrf || sam
+
+package machine
+
+// DeviceID returns an identifier that is unique within
+// a particular chipset.
+//
+// The identity is one burnt into the MCU itself, or the
+// flash chip at time of manufacture.
+//
+// It's possible that two different vendors may allocate
+// the same DeviceID, so callers should take this into
+// account if needing to generate a globally unique id.
+//
+// The length of the hardware ID is vendor-specific, but
+// 8 bytes (64 bits) and 16 bytes (128 bits) are common.
+var _ = (func() []byte)(DeviceID)

src/machine/machine_atsam.go

@@ -0,0 +1,31 @@
+//go:build sam
+
+package machine
+
+import (
+	"runtime/volatile"
+	"unsafe"
+)
+
+var deviceID [16]byte
+
+// DeviceID returns an identifier that is unique within
+// a particular chipset.
+//
+// The identity is one burnt into the MCU itself, or the
+// flash chip at time of manufacture.
+//
+// It's possible that two different vendors may allocate
+// the same DeviceID, so callers should take this into
+// account if needing to generate a globally unique id.
+//
+// The length of the hardware ID is vendor-specific, but
+// 8 bytes (64 bits) and 16 bytes (128 bits) are common.
+func DeviceID() []byte {
+	for i := 0; i < len(deviceID); i++ {
+		word := (*volatile.Register32)(unsafe.Pointer(deviceIDAddr[i/4])).Get()
+		deviceID[i] = byte(word >> ((i % 4) * 8))
+	}
+
+	return deviceID[:]
+}

src/machine/machine_atsamd21.go

@@ -18,6 +18,9 @@ import (
 
 const deviceName = sam.Device
 
+// DS40001882F, Section 10.3.3: Serial Number
+var deviceIDAddr = []uintptr{0x0080A00C, 0x0080A040, 0x0080A044, 0x0080A048}
+
 const (
 	PinAnalog    PinMode = 1
 	PinSERCOM    PinMode = 2

src/machine/machine_atsamd51.go

@@ -18,6 +18,9 @@ import (
 
 const deviceName = sam.Device
 
+// DS60001507, Section 9.6: Serial Number
+var deviceIDAddr = []uintptr{0x008061FC, 0x00806010, 0x00806014, 0x00806018}
+
 func CPUFrequency() uint32 {
 	return 120000000
 }

src/machine/machine_nrf.go

@@ -12,6 +12,34 @@ import (
 
 const deviceName = nrf.Device
 
+var deviceID [8]byte
+
+// DeviceID returns an identifier that is unique within
+// a particular chipset.
+//
+// The identity is one burnt into the MCU itself, or the
+// flash chip at time of manufacture.
+//
+// It's possible that two different vendors may allocate
+// the same DeviceID, so callers should take this into
+// account if needing to generate a globally unique id.
+//
+// The length of the hardware ID is vendor-specific, but
+// 8 bytes (64 bits) is common.
+func DeviceID() []byte {
+	words := make([]uint32, 2)
+	words[0] = nrf.FICR.DEVICEID[0].Get()
+	words[1] = nrf.FICR.DEVICEID[1].Get()
+
+	for i := 0; i < 8; i++ {
+		shift := (i % 4) * 8
+		w := i / 4
+		deviceID[i] = byte(words[w] >> shift)
+	}
+
+	return deviceID[:]
+}
+
 const (
 	PinInput         PinMode = (nrf.GPIO_PIN_CNF_DIR_Input << nrf.GPIO_PIN_CNF_DIR_Pos) | (nrf.GPIO_PIN_CNF_INPUT_Connect << nrf.GPIO_PIN_CNF_INPUT_Pos)
 	PinInputPullup   PinMode = PinInput | (nrf.GPIO_PIN_CNF_PULL_Pullup << nrf.GPIO_PIN_CNF_PULL_Pos)

src/machine/machine_rp2040_flash.go

@@ -13,6 +13,32 @@ func EnterBootloader() {
 	enterBootloader()
 }
 
+// 13 = 1 + FLASH_RUID_DUMMY_BYTES(4) + FLASH_RUID_DATA_BYTES(8)
+var deviceIDBuf [13]byte
+
+// DeviceID returns an identifier that is unique within
+// a particular chipset.
+//
+// The identity is one burnt into the MCU itself, or the
+// flash chip at time of manufacture.
+//
+// It's possible that two different vendors may allocate
+// the same DeviceID, so callers should take this into
+// account if needing to generate a globally unique id.
+//
+// The length of the hardware ID is vendor-specific, but
+// 8 bytes (64 bits) is common.
+func DeviceID() []byte {
+	deviceIDBuf[0] = 0x4b // FLASH_RUID_CMD
+
+	err := doFlashCommand(deviceIDBuf[:], deviceIDBuf[:])
+	if err != nil {
+		panic(err)
+	}
+
+	return deviceIDBuf[5:13]
+}
+
 // compile-time check for ensuring we fulfill BlockDevice interface
 var _ BlockDevice = flashBlockDevice{}
 

src/machine/machine_rp2040_rom.go

@@ -93,6 +93,33 @@ static ram_func void flash_enable_xip_via_boot2() {
 	((void (*)(void))boot2_copyout+1)();
 }
 
+#define IO_QSPI_BASE 0x40018000
+#define IO_QSPI_GPIO_QSPI_SS_CTRL_OUTOVER_BITS         0x00000300
+#define IO_QSPI_GPIO_QSPI_SS_CTRL_OUTOVER_MSB          9
+#define IO_QSPI_GPIO_QSPI_SS_CTRL_OUTOVER_LSB          8
+#define IO_QSPI_GPIO_QSPI_SS_CTRL_OUTOVER_VALUE_LOW    0x2
+#define IO_QSPI_GPIO_QSPI_SS_CTRL_OUTOVER_VALUE_HIGH   0x3
+
+#define XIP_SSI_BASE 0x18000000
+#define ssi_hw ((ssi_hw_t *)XIP_SSI_BASE)
+#define SSI_SR_OFFSET      0x00000028
+#define SSI_DR0_OFFSET     0x00000060
+#define SSI_SR_TFNF_BITS   0x00000002
+#define SSI_SR_RFNE_BITS   0x00000008
+
+void ram_func flash_cs_force(bool high) {
+    uint32_t field_val = high ?
+        IO_QSPI_GPIO_QSPI_SS_CTRL_OUTOVER_VALUE_HIGH :
+        IO_QSPI_GPIO_QSPI_SS_CTRL_OUTOVER_VALUE_LOW;
+
+	// &ioqspi_hw->io[1].ctrl
+	uint32_t *addr = (uint32_t*)(IO_QSPI_BASE + (1 * 8) + 4);
+
+	*addr = ((*addr) & !IO_QSPI_GPIO_QSPI_SS_CTRL_OUTOVER_BITS)
+		| (field_val << IO_QSPI_GPIO_QSPI_SS_CTRL_OUTOVER_LSB);
+
+}
+
 // See https://github.com/raspberrypi/pico-sdk/blob/master/src/rp2_common/hardware_flash/flash.c#L86
 void ram_func flash_range_write(uint32_t offset, const uint8_t *data, size_t count)
 {
@@ -132,13 +159,62 @@ void ram_func flash_erase_blocks(uint32_t offset, size_t count)
 	flash_enable_xip_via_boot2();
 }
 
+void ram_func flash_do_cmd(const uint8_t *txbuf, uint8_t *rxbuf, size_t count) {
+	flash_connect_internal_fn flash_connect_internal_func = (flash_connect_internal_fn) rom_func_lookup(ROM_FUNC_CONNECT_INTERNAL_FLASH);
+	flash_exit_xip_fn flash_exit_xip_func = (flash_exit_xip_fn) rom_func_lookup(ROM_FUNC_FLASH_EXIT_XIP);
+	flash_flush_cache_fn flash_flush_cache_func = (flash_flush_cache_fn) rom_func_lookup(ROM_FUNC_FLASH_FLUSH_CACHE);
+
+	flash_init_boot2_copyout();
+
+	__compiler_memory_barrier();
+
+	flash_connect_internal_func();
+	flash_exit_xip_func();
+
+	flash_cs_force(0);
+	size_t tx_remaining = count;
+	size_t rx_remaining = count;
+	// We may be interrupted -- don't want FIFO to overflow if we're distracted.
+	const size_t max_in_flight = 16 - 2;
+	while (tx_remaining || rx_remaining) {
+		uint32_t flags = *(uint32_t*)(XIP_SSI_BASE + SSI_SR_OFFSET);
+		bool can_put = !!(flags & SSI_SR_TFNF_BITS);
+		bool can_get = !!(flags & SSI_SR_RFNE_BITS);
+		if (can_put && tx_remaining && rx_remaining - tx_remaining < max_in_flight) {
+			*(uint32_t*)(XIP_SSI_BASE + SSI_DR0_OFFSET) = *txbuf++;
+			--tx_remaining;
+		}
+		if (can_get && rx_remaining) {
+			*rxbuf++ = (uint8_t)*(uint32_t*)(XIP_SSI_BASE + SSI_DR0_OFFSET);
+			--rx_remaining;
+		}
+	}
+	flash_cs_force(1);
+
+	flash_flush_cache_func();
+	flash_enable_xip_via_boot2();
+}
+
 */
 import "C"
 
 func enterBootloader() {
 	C.reset_usb_boot(0, 0)
 }
 
+func doFlashCommand(tx []byte, rx []byte) error {
+	if len(tx) != len(rx) {
+		return errFlashInvalidWriteLength
+	}
+
+	C.flash_do_cmd(
+		(*C.uint8_t)(unsafe.Pointer(&tx[0])),
+		(*C.uint8_t)(unsafe.Pointer(&rx[0])),
+		C.ulong(len(tx)))
+
+	return nil
+}
+
 // Flash related code
 const memoryStart = C.XIP_BASE // memory start for purpose of erase