machine/microbit-v2: add initial support based on work done by @alankrantas thank you!

Signed-off-by: deadprogram <ron@hybridgroup.com>

Makefile

@@ -209,6 +209,8 @@ smoketest:
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=microbit            examples/microbit-blink
 	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=microbit-v2         examples/microbit-blink
+	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/pininterrupt
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/serial

src/machine/board_microbit-v2.go

@@ -0,0 +1,114 @@
+// +build microbit_v2
+
+package machine
+
+// The micro:bit does not have a 32kHz crystal on board.
+const HasLowFrequencyCrystal = false
+
+const (
+	LED  = P13
+	LED1 = LED
+)
+
+// Buttons on the micro:bit v2 (A and B)
+const (
+	BUTTON  Pin = BUTTONA
+	BUTTONA Pin = P5
+	BUTTONB Pin = P11
+)
+
+// UART pins
+const (
+	UART_TX_PIN Pin = P34
+	UART_RX_PIN Pin = P33
+)
+
+// ADC pins
+const (
+	ADC0 Pin = P0
+	ADC1 Pin = P1
+	ADC2 Pin = P2
+)
+
+// I2C0 (internal) pins
+const (
+	SDA_PIN  Pin = SDA0_PIN
+	SCL_PIN  Pin = SCL0_PIN
+	SDA0_PIN Pin = P30
+	SCL0_PIN Pin = P31
+)
+
+// I2C1 (external) pins
+const (
+	SDA1_PIN Pin = P20
+	SCL1_PIN Pin = P19
+)
+
+// SPI pins
+const (
+	SPI0_SCK_PIN Pin = P13
+	SPI0_SDO_PIN Pin = P15
+	SPI0_SDI_PIN Pin = P14
+)
+
+// GPIO/Analog pins
+const (
+	P0  Pin = 2
+	P1  Pin = 3
+	P2  Pin = 4
+	P3  Pin = 31
+	P4  Pin = 28
+	P5  Pin = 14
+	P6  Pin = 37
+	P7  Pin = 11
+	P8  Pin = 10
+	P9  Pin = 9
+	P10 Pin = 30
+	P11 Pin = 23
+	P12 Pin = 12
+	P13 Pin = 17
+	P14 Pin = 1
+	P15 Pin = 13
+	P16 Pin = 34
+	P19 Pin = 26
+	P20 Pin = 32
+	P21 Pin = 21
+	P22 Pin = 22
+	P23 Pin = 15
+	P24 Pin = 24
+	P25 Pin = 19
+	P26 Pin = 36
+	P27 Pin = 0
+	P28 Pin = 20
+	P29 Pin = 5
+	P30 Pin = 16
+	P31 Pin = 8
+	P32 Pin = 25
+	P33 Pin = 40
+	P34 Pin = 6
+)
+
+// LED matrix pins
+const (
+	LED_COL_1 Pin = P4
+	LED_COL_2 Pin = P7
+	LED_COL_3 Pin = P3
+	LED_COL_4 Pin = P6
+	LED_COL_5 Pin = P10
+	LED_ROW_1 Pin = P21
+	LED_ROW_2 Pin = P22
+	LED_ROW_3 Pin = P23
+	LED_ROW_4 Pin = P24
+	LED_ROW_5 Pin = P25
+)
+
+// USB CDC identifiers
+const (
+	usb_STRING_PRODUCT      = "BBC micro:bit V2"
+	usb_STRING_MANUFACTURER = "BBC"
+)
+
+var (
+	usb_VID uint16 = 0x0d28
+	usb_PID uint16 = 0x0204
+)

src/machine/machine_nrf52833.go

@@ -0,0 +1,89 @@
+// +build nrf52833
+
+package machine
+
+import (
+	"device/nrf"
+)
+
+// Hardware pins
+const (
+	P0_00 Pin = 0
+	P0_01 Pin = 1
+	P0_02 Pin = 2
+	P0_03 Pin = 3
+	P0_04 Pin = 4
+	P0_05 Pin = 5
+	P0_06 Pin = 6
+	P0_07 Pin = 7
+	P0_08 Pin = 8
+	P0_09 Pin = 9
+	P0_10 Pin = 10
+	P0_11 Pin = 11
+	P0_12 Pin = 12
+	P0_13 Pin = 13
+	P0_14 Pin = 14
+	P0_15 Pin = 15
+	P0_16 Pin = 16
+	P0_17 Pin = 17
+	P0_18 Pin = 18
+	P0_19 Pin = 19
+	P0_20 Pin = 20
+	P0_21 Pin = 21
+	P0_22 Pin = 22
+	P0_23 Pin = 23
+	P0_24 Pin = 24
+	P0_25 Pin = 25
+	P0_26 Pin = 26
+	P0_27 Pin = 27
+	P0_28 Pin = 28
+	P0_29 Pin = 29
+	P0_30 Pin = 30
+	P0_31 Pin = 31
+	P1_00 Pin = 32
+	P1_01 Pin = 33
+	P1_02 Pin = 34
+	P1_03 Pin = 35
+	P1_04 Pin = 36
+	P1_05 Pin = 37
+	P1_06 Pin = 38
+	P1_07 Pin = 39
+	P1_08 Pin = 40
+	P1_09 Pin = 41
+	P1_10 Pin = 42
+	P1_11 Pin = 43
+	P1_12 Pin = 44
+	P1_13 Pin = 45
+	P1_14 Pin = 46
+	P1_15 Pin = 47
+)
+
+var (
+	UART0 = NRF_UART0
+)
+
+// Get peripheral and pin number for this GPIO pin.
+func (p Pin) getPortPin() (*nrf.GPIO_Type, uint32) {
+	if p >= 32 {
+		return nrf.P1, uint32(p - 32)
+	} else {
+		return nrf.P0, uint32(p)
+	}
+}
+
+func (uart UART) setPins(tx, rx Pin) {
+	nrf.UART0.PSEL.TXD.Set(uint32(tx))
+	nrf.UART0.PSEL.RXD.Set(uint32(rx))
+}
+
+func (i2c I2C) setPins(scl, sda Pin) {
+	i2c.Bus.PSEL.SCL.Set(uint32(scl))
+	i2c.Bus.PSEL.SDA.Set(uint32(sda))
+}
+
+// PWM
+var (
+	pwmChannelPins     = [4]uint32{0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF}
+	pwms               = [4]*nrf.PWM_Type{nrf.PWM0, nrf.PWM1, nrf.PWM2, nrf.PWM3}
+	pwmChannelSequence [4]uint16
+)

src/machine/machine_nrf528xx.go

@@ -1,4 +1,4 @@
-// +build nrf52 nrf52840
+// +build nrf52 nrf52840 nrf52833
 
 package machine
 

targets/microbit-v2.json

@@ -0,0 +1,8 @@
+{
+	"inherits": ["nrf52833"],
+	"build-tags": ["microbit_v2"],
+	"flash-method": "msd",
+	"openocd-interface": "cmsis-dap",
+	"msd-volume-name": "MICROBIT",
+	"msd-firmware-name": "firmware.hex"
+}

targets/nrf52833.json

@@ -0,0 +1,17 @@
+{
+	"inherits": ["cortex-m4"],
+	"build-tags": ["nrf52833", "nrf"],
+	"cflags": [
+		"-Qunused-arguments",
+		"-DNRF52833_XXAA",
+		"-I{root}/lib/CMSIS/CMSIS/Include",
+		"-I{root}/lib/nrfx/mdk"
+	],
+	"linkerscript": "targets/nrf52833.ld",
+	"extra-files": [
+		"lib/nrfx/mdk/system_nrf52833.c",
+		"src/device/nrf/nrf52833.s"
+	],
+	"openocd-transport": "swd",
+	"openocd-target": "nrf52"
+}

targets/nrf52833.ld

@@ -0,0 +1,10 @@
+
+MEMORY
+{
+    FLASH_TEXT (rw) : ORIGIN = 0x00000000, LENGTH = 0x80000
+    RAM (xrw)       : ORIGIN = 0x20000000, LENGTH = 0x20000
+}
+
+_stack_size = 4K;
+
+INCLUDE "targets/arm.ld"