From 61af20bdb9d5ca85cd328ddb42720e34fa421aeb Mon Sep 17 00:00:00 2001
From: deadprogram <ron@hybridgroup.com>
Date: Tue, 7 May 2024 17:18:18 +0200
Subject: [PATCH] renesas: WIP

Signed-off-by: deadprogram <ron@hybridgroup.com>
---
 src/runtime/runtime_renesas.go | 89 ++++++++++++++++++++++++++++++++++
 targets/ra4m1.json             | 10 ++++
 targets/ra4m1.ld               | 10 ++++
 3 files changed, 109 insertions(+)
 create mode 100644 src/runtime/runtime_renesas.go
 create mode 100644 targets/ra4m1.json
 create mode 100644 targets/ra4m1.ld

diff --git a/src/runtime/runtime_renesas.go b/src/runtime/runtime_renesas.go
new file mode 100644
index 000000000..895874227
--- /dev/null
+++ b/src/runtime/runtime_renesas.go
@@ -0,0 +1,89 @@
+//go:build renasas
+
+package runtime
+
+import (
+	"device/arm"
+	"machine"
+)
+
+// machineTicks is provided by package machine.
+func machineTicks() uint64 {
+	return 0
+}
+
+// machineLightSleep is provided by package machine.
+func machineLightSleep(uint64) {
+	return
+}
+
+type timeUnit int64
+
+// ticks returns the number of ticks (microseconds) elapsed since power up.
+func ticks() timeUnit {
+	t := machineTicks()
+	return timeUnit(t)
+}
+
+func ticksToNanoseconds(ticks timeUnit) int64 {
+	return int64(ticks) * 1000
+}
+
+func nanosecondsToTicks(ns int64) timeUnit {
+	return timeUnit(ns / 1000)
+}
+
+func sleepTicks(d timeUnit) {
+	if d <= 0 {
+		return
+	}
+
+	if hasScheduler {
+		// With scheduler, sleepTicks may return early if an interrupt or
+		// event fires - so scheduler can schedule any go routines now
+		// eligible to run
+		machineLightSleep(uint64(d))
+		return
+	}
+
+	// Busy loop
+	sleepUntil := ticks() + d
+	for ticks() < sleepUntil {
+	}
+}
+
+func waitForEvents() {
+	arm.Asm("wfe")
+}
+
+func putchar(c byte) {
+	machine.Serial.WriteByte(c)
+}
+
+func getchar() byte {
+	for machine.Serial.Buffered() == 0 {
+		Gosched()
+	}
+	v, _ := machine.Serial.ReadByte()
+	return v
+}
+
+func buffered() int {
+	return machine.Serial.Buffered()
+}
+
+// machineInit is provided by package machine.
+func machineInit() {
+	return
+}
+
+func init() {
+	machineInit()
+}
+
+//export Reset_Handler
+func main() {
+	preinit()
+	run()
+	exit(0)
+}
diff --git a/targets/ra4m1.json b/targets/ra4m1.json
new file mode 100644
index 000000000..82d90f6c2
--- /dev/null
+++ b/targets/ra4m1.json
@@ -0,0 +1,10 @@
+{
+	"inherits": ["cortex-m4"],
+	"build-tags": ["ra4m1", "renesas"],
+	"linkerscript": "targets/ra4m1.ld",
+	"extra-files": [
+		"src/device/renesas/r7fa4m2ad.s"
+	],
+	"openocd-transport": "swd",
+	"openocd-target": "atsame5x"
+}
diff --git a/targets/ra4m1.ld b/targets/ra4m1.ld
new file mode 100644
index 000000000..908ce6a84
--- /dev/null
+++ b/targets/ra4m1.ld
@@ -0,0 +1,10 @@
+
+MEMORY
+{
+    FLASH_TEXT (rw) : ORIGIN = 0x00000000+0x4000, LENGTH = 0x00080000-0x4000  /* First 16KB used by bootloader */
+    RAM (xrw)       : ORIGIN = 0x20000000, LENGTH = 0x00030000
+}
+
+_stack_size = 4K;
+
+INCLUDE "targets/arm.ld"