From 9792a2d2230d9e4e8bd3dec96e37e4107a6d8a37 Mon Sep 17 00:00:00 2001
From: arighi <arighi@38d2e660-2303-0410-9eaa-f027e97ec537>
Date: Wed, 19 May 2010 12:23:23 +0000
Subject: [PATCH] ARM7TDMI: get rid of gcc's __attribute__((interrupt)).

GCC is too buggy when generating __attribute__((interrupt)) functions on
ARM (see previous stack corruption issues).

Get rid of this definition and use __attribute__((naked)) instead,
implementing all the required instructions in assembly to properly save
and restore context from an ISR.

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@3716 38d2e660-2303-0410-9eaa-f027e97ec537
---
 bertos/cpu/irq.h | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/bertos/cpu/irq.h b/bertos/cpu/irq.h
index bda8b497..6eac70fd 100644
--- a/bertos/cpu/irq.h
+++ b/bertos/cpu/irq.h
@@ -350,7 +350,7 @@
 					__isr_##func();				\
 					IRQ_EXIT();				\
 				}						\
-				static void __isr_##func(void)
+				static NOINLINE void __isr_##func(void)
 			/**
 			 * Interrupt service routine prototype: can be used for
 			 * forward declarations.
@@ -377,7 +377,7 @@
 		#endif /* CONFIG_KERN_PREEMPT */
 
 		#ifndef ISR_FUNC
-			#define ISR_FUNC  __attribute__((interrupt))
+			#define ISR_FUNC __attribute__((naked))
 		#endif
 		#ifndef DECLARE_ISR
 			#define DECLARE_ISR(func) \
@@ -394,9 +394,14 @@
 				static NOINLINE void __isr_##func(void);		\
 				void ISR_FUNC func(void)				\
 				{							\
+					asm volatile (					\
+						"sub	lr, lr, #4\n\t"			\
+						"stmfd	sp!, {r0-r3, ip, lr}\n\t");	\
 					__isr_##func();					\
+					asm volatile (					\
+						"ldmfd sp!, {r0-r3, ip, pc}^\n\t");	\
 				}							\
-				static void __isr_##func(void)
+				static NOINLINE void __isr_##func(void)
 		#endif
 		#ifndef DECLARE_ISR_CONTEXT_SWITCH
 			#define DECLARE_ISR_CONTEXT_SWITCH(func) DECLARE_ISR(func)
-- 
2.25.1