From e9fbe057d95db93038fea2cc16dcdbd097665ab3 Mon Sep 17 00:00:00 2001
From: Andrea Barisani <andrea@inversepath.com>
Date: Thu, 17 Oct 2024 13:13:12 +0200
Subject: [PATCH] add support to wake tamago < 1.23 applets on >= 1.23 os
 (#284)

* add support to wake tamago < 1.23 applets on >= 1.23 os

* Update trusted_os/handler.go

Co-authored-by: Martin Hutchinson <mhutchinson@gmail.com>

* tidying

---------

Co-authored-by: Martin Hutchinson <mhutchinson@gmail.com>
---
 trusted_os/handler.go |  1 +
 trusted_os/handler.s  | 43 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/trusted_os/handler.go b/trusted_os/handler.go
index 2937eb1..5ec2669 100644
--- a/trusted_os/handler.go
+++ b/trusted_os/handler.go
@@ -36,6 +36,7 @@ var irqHandler = make(map[int]func())
 
 // defined in handler.s
 func wakeHandler(g uint32, p uint32)
+func wakeHandlerPreGo123(g uint32, p uint32)
 
 func isr() {
 	irq := imx6ul.GIC.GetInterrupt(true)
diff --git a/trusted_os/handler.s b/trusted_os/handler.s
index 466185a..570fb5f 100644
--- a/trusted_os/handler.s
+++ b/trusted_os/handler.s
@@ -15,6 +15,16 @@
 #include "go_asm.h"
 #include "textflag.h"
 
+// These defines are only used to aid applet runtime backward compatiblity,
+// within wakeHandlerPreGo123, and represent timer structs offsets fo Go <
+// 1.23.
+#define g_timer				208
+#define timer_nextwhen			36
+#define timer_status			44
+#define const_timerModifiedEarlier	7
+#define p_timerModifiedEarliest		2384
+
+// Supports tamago >= 1.23 applet runtime.
 TEXT ·wakeHandler(SB),$0-8
 	MOVW	handlerG+0(FP), R0
 	MOVW	handlerP+4(FP), R1
@@ -28,3 +38,36 @@ TEXT ·wakeHandler(SB),$0-8
 	B	runtime·WakeG(SB)
 done:
 	RET
+
+// Supports tamago < 1.23 applet runtime.
+TEXT ·wakeHandlerPreGo123(SB),$0-8
+	MOVW	handlerG+0(FP), R0
+	MOVW	handlerP+4(FP), R1
+
+	CMP	$0, R0
+	B.EQ	done
+
+	CMP	$0, R1
+	B.EQ	done
+
+	MOVW	(g_timer)(R0), R0
+	CMP	$0, R0
+	B.EQ	done
+
+	// g->timer.nextwhen = 1
+	MOVW	$1, R2
+	MOVW	R2, (timer_nextwhen+0)(R0)
+	MOVW	$0, R2
+	MOVW	R2, (timer_nextwhen+4)(R0)
+
+	// g->timer.status = timerModifiedEarlier
+	MOVW	$const_timerModifiedEarlier, R2
+	MOVW	R2, (timer_status+0)(R0)
+
+	// g->m->p.timerModifiedEarliest = 1
+	MOVW	$1, R2
+	MOVW	R2, (p_timerModifiedEarliest)(R1)
+	MOVW	$0, R2
+	MOVW	R2, (p_timerModifiedEarliest+4)(R1)
+done:
+	RET