Implement irqsave/restore

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@747 42af7a65-404d-4744-a932-0658087f49c3

arch/z80/include/ez80/types.h

@@ -81,10 +81,10 @@ typedef long sint32;
 typedef unsigned long uint32;
 
 /* This is the size of the interrupt state save returned by irqsave().
- * It holds the contents of the interrupt vector address
+ * It holds the AF regiser pair + a zero pad byte
  */
 
-typedef ubyte irqstate_t;
+typedef uint24 irqstate_t;
 
 #endif /* __ASSEMBLY__ */
 

arch/z80/src/ez80/Make.defs

@@ -43,7 +43,8 @@ CMN_CSRCS	= up_initialize.c up_allocateheap.c up_createstack.c \
 		  up_reprioritizertr.c up_idle.c up_assert.c up_doirq.c \
 		  up_mdelay.c up_udelay.c up_usestack.c
 
-CHIP_ASRCS	= ez80_startup.asm ez80_saveusercontext.asm ez80_restorecontext.asm
+CHIP_ASRCS	= ez80_startup.asm ez80_irqsave.asm \
+		  ez80_saveusercontext.asm ez80_restorecontext.asm
 ifeq ($(CONFIG_ARCH_CHIP_EZ80F91),y)
 CHIP_ASRCS	+= ez80f91_init.asm
 endif

arch/z80/src/ez80/ez80_irq.c

@@ -78,30 +78,13 @@ chipreg_t *current_regs;
 
 void up_irqinitialize(void)
 {
-}
+  current_regs = NULL;
   
-/****************************************************************************
- * Name: irqsave
- *
- * Description:
- *   Disable all interrupts; return previous interrupt state
- *
- ****************************************************************************/
+  /* And finally, enable interrupts */
 
-irqstate_t irqsave(void)
-{
-}
-
-/****************************************************************************
- * Name: irqrestore
- *
- * Description:
- *   Restore previous interrupt state
- *
- ****************************************************************************/
-
-void irqrestore(irqstate_t flags)
-{
+#ifndef CONFIG_SUPPRESS_INTERRUPTS
+  asm("ei");
+#endif
 }
 
 /****************************************************************************

arch/z80/src/ez80/ez80_irqsave.asm

@@ -0,0 +1,88 @@
+;**************************************************************************
+; arch/z80/src/ez80/ez80_irqsave.asm
+;
+;   Copyright (C) 2008 Gregory Nutt. All rights reserved.
+;   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+;
+; Redistribution and use in source and binary forms, with or without
+; modification, are permitted provided that the following conditions
+; are met:
+;
+; 1. Redistributions of source code must retain the above copyright
+;    notice, this list of conditions and the following disclaimer.
+; 2. Redistributions in binary form must reproduce the above copyright
+;    notice, this list of conditions and the following disclaimer in
+;    the documentation and/or other materials provided with the
+;    distribution.
+; 3. Neither the name NuttX nor the names of its contributors may be
+;    used to endorse or promote products derived from this software
+;    without specific prior written permission.
+;
+; THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+; "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+; LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+; FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+; COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+; INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+; BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+; OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+; AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+; LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+; ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+; POSSIBILITY OF SUCH DAMAGE.
+;
+;**************************************************************************
+
+;**************************************************************************
+; Global Symbols Imported
+;**************************************************************************
+
+;**************************************************************************
+; Global Symbols Expported
+;**************************************************************************
+
+	xdef	_irqsave
+	xdef	_irqrestore
+
+;**************************************************************************
+; Code
+;**************************************************************************
+
+	segment CODE
+	.assume ADL=1
+
+;****************************************************************************
+;* Name: irqstate_t irqsave(void)
+;*
+;* Description:
+;*   Disable all interrupts; return previous interrupt state
+;*
+;****************************************************************************
+
+_irqsave:
+	ld	a, i		; AF = interrupt state
+	di			; Interrupts are disabled (does not affect F)
+	push	af		; Transfer to HL via the stack
+	pop	hl		;
+	ret			; And return
+
+;****************************************************************************
+;* Name: void irqrestore(irqstate_t flags)
+;*
+;* Description:
+;*   Restore previous interrupt state
+;*
+;****************************************************************************
+
+_irqrestore:
+	di			; Assume disabled
+	pop	hl		; HL = return address
+	pop	af		; AF Parity bit holds interrupt state
+	jp	po, _disabled	; Skip over re-enable if Parity odd
+	ei			; Re-enable interrupts
+_disabled:
+	push	af		; Restore stack
+	push	hl		;
+	ret			; and return
+
+	end

arch/z80/src/ez80/ez80_vectors.asm

@@ -81,20 +81,6 @@ irqhandler: macro vectno
 	jp	_ez80_rstcommon		; Remaining RST handling is common
 	endmac	irqhandler
 
-; Save Interrupt State
-irqsave: macro
-	ld	a, i			; sets parity bit to value of IEF2
-	push af
-	di				; disable interrupts while loading table 
-	endmac	irqsave
-
-; Restore Interrupt State
-irqrestore: macro
-	pop	af
-	jp	po, $+5			; parity bit is IEF2
-	ei
-	endmac	irqrestore
-
 ;**************************************************************************
 ; Reset entry points
 ;**************************************************************************