First successful z80 compile & link

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@457 42af7a65-404d-4744-a932-0658087f49c3

29 files changed, 430 insertions, 282 deletions

diff --git a/nuttx/arch/z80/include/types.h b/nuttx/arch/z80/include/types.h
index d650e5a01..ade00123a 100644
--- a/nuttx/arch/z80/include/types.h
+++ b/nuttx/arch/z80/include/types.h
@@ -76,7 +76,7 @@ typedef unsigned long uint32;
  * irqsave()
  */
 
-typedef unsigned char irqstate_t;
+typedef uint16 irqstate_t;
 
 #endif /* __ASSEMBLY__ */
 
diff --git a/nuttx/arch/z80/include/z80/irq.h b/nuttx/arch/z80/include/z80/irq.h
index c68dd76f9..059bf0486 100644
--- a/nuttx/arch/z80/include/z80/irq.h
+++ b/nuttx/arch/z80/include/z80/irq.h
@@ -77,13 +77,14 @@
  * Public Types
  ****************************************************************************/
 
+#ifndef __ASSEMBLY__
+
 /* This is the the type of the register save array */
 
 typedef uint16 chipreg_t;
 
 /* This struct defines the way the registers are stored. */
 
-#ifndef __ASSEMBLY__
 struct xcptcontext
 {
   /* Register save area */
@@ -120,8 +121,8 @@ extern "C" {
 #define EXTERN extern
 #endif
 
-EXTERN irqstate_t irqsave(void);
-EXTERN void       irqrestore(irqstate_t flags);
+EXTERN irqstate_t irqsave(void) __naked;
+EXTERN void       irqrestore(irqstate_t flags) __naked;
 
 #undef EXTERN
 #ifdef __cplusplus
diff --git a/nuttx/arch/z80/src/Makefile b/nuttx/arch/z80/src/Makefile
index 0aabc09bb..dab152b0c 100644
--- a/nuttx/arch/z80/src/Makefile
+++ b/nuttx/arch/z80/src/Makefile
@@ -44,13 +44,10 @@
 
 MKDEP 		= $(TOPDIR)/tools/mkdeps.sh
 
-CFLAGS		+= -I$(ARCH_SRCDIR)/chip -I$(ARCH_SRCDIR)/common -I$(TOPDIR)/sched
-LDFLAGS		= $(ARCHSCRIPT)
-
-LDPATHES	= $(addprefix -L$(TOPDIR)/,$(dir $(LINKLIBS)))
-LDLIBS		= $(patsubst lib%,-l%,$(basename $(notdir $(LINKLIBS))))
+# CFLAGS, CPPFLAGS, ASFLAGS, LDFLAGS are set in $(TOPDIR)/Make.defs
 
-CPPFLAGS	= $(ARCHINCLUDES) $(ARCHDEFINES) -D__ASSEMBLY__
+CFLAGS		+= -I$(ARCH_SRCDIR)/chip -I$(ARCH_SRCDIR)/common -I$(TOPDIR)/sched
+CPPFLAGS	+= -D__ASSEMBLY__
 
 ############################################################################
 # Files and directories
@@ -62,7 +59,7 @@ HEAD_AOBJ	= $(HEAD_ASRC:$(ASMEXT)=$(OBJEXT))
 # Assembly sources and objects
 
 ASRCS		= $(CHIP_ASRCS) $(CMN_ASRCS)
-AOBJS		= $(ASRCS:.S=$(OBJEXT))
+AOBJS		= $(ASRCS:$(ASMEXT)=$(OBJEXT))
 
 # C sources and objects
 
@@ -74,18 +71,9 @@ COBJS		= $(CSRCS:.c=$(OBJEXT))
 SRCS		= $(ASRCS) $(CSRCS)
 OBJS		= $(AOBJS) $(COBJS)
 
-# Sources and objects for the test target (plus HEAD_AOBJ
-
-TEST_AOBJS	= $(TEST_ASRCS:$(ASMEXT)=$(OBJEXT))
-TEST_COBJS	= $(TEST_CSRCS:.c=$(OBJEXT))
-
-TESTSRCS	= up_irqtest.c
-TESTOBJS	= $(TESTSRCS:.c=$(OBJEXT))
-TESTEXTRAOBJS	= up_savecontext$(OBJEXT) up_restorecontext$(OBJEXT)
-
 # Sources that can have dependencies (no .asm files)
 
-DEPSRCS		= $(SRCS)
+DEPSRCS		= $(CSRCS)
 
 # Directories
 
@@ -105,16 +93,7 @@ HEAP_BASE	= ${shell \
 				cat pass1.mem | grep "ROM/EPROM/FLASH" | \
 				sed -e "s/[ ][ ]*/ /g" | cut -d' ' -f4 ; \
 			else \
-				echo $(DEF_HEAP_BASE) ; \
-			fi \
-		   }
-
-STACK_BASE	= ${shell \
-			if [ -e pass1.mem ]; then \
-				cat pass1.mem | grep "Stack starts" | \
-				cut -d' ' -f4 ; \
-			else \
-				echo $(DEF_STACK_BASE) ; \
+				echo "(UP_HEAP1_END - 8192)" ; \
 			fi \
 		   }
 
@@ -123,12 +102,24 @@ STACK_BASE	= ${shell \
 
 all: $(HEAD_AOBJ) libarch$(LIBEXT)
 
-$(AOBJS) $(HEAD_AOBJ) $(TEST_AOBJS): %$(OBJEXT): %$(ASMEXT)
+$(AOBJS) $(HEAD_AOBJ): %$(OBJEXT): %$(ASMEXT)
 	$(AS) $(ASFLAGS) $@ $<
 
-$(COBJS) $(TEST_COBJS): %$(OBJEXT): %.c
+$(COBJS): %$(OBJEXT): %.c
 	$(CC) -c $(CFLAGS) $< -o $@
 
+# This is a kludge to work around some conflicting symbols in libsdcc.liXqueb
+
+$(SDCCLIBDIR)/myz80.lib: $(SDCCLIBDIR)/$(SDCCLIB)
+	@cat $(SDCCLIBDIR)/$(SDCCLIB) | \
+		grep -v calloc  | grep -v malloc  | grep -v realloc  | \
+		grep -v free    | grep -v vprintf | grep -v _strncpy | \
+		grep -v _strchr | grep -v _strlen | grep -v _strcmp  | \
+		grep -v _strcpy | grep -v _memcmp | grep -v _memcpy  | \
+		grep -v _memset | grep -v crt0 \
+		> myz80.lib
+	@sudo mv -f myz80.lib $(SDCCLIBDIR)/myz80.lib
+
 # Create a header file that contains addressing information needed by the code
 
 pass1.mem:
@@ -137,18 +128,12 @@ up_mem.h: pass1.mem
 	@echo "#ifndef __ARCH_MEM_H" >up_mem.h
 	@echo "#define __ARCH_MEM_H" >>up_mem.h
 	@echo "" >>up_mem.h
-	@echo "#define UP_DEFAULT_STACK_BASE $(DEF_STACK_BASE)" >>up_mem.h
 	@echo "#define UP_DEFAULT_HEAP_BASE $(DEF_HEAP_BASE)" >> up_mem.h
 	@echo "" >>up_mem.h
-	@echo "#define UP_STACK_BASE         $(STACK_BASE)" >>up_mem.h
-	@echo "#if UP_STACK_BASE > UP_DEFAULT_STACK_BASE" >>up_mem.h
-	@echo "#  error \"Stack overlap:  $(DEF_STACK_BASE) < $(STACK_BASE)\""  >>up_mem.h
-	@echo "#elif UP_STACK_BASE < UP_DEFAULT_STACK_BASE" >>up_mem.h
-	@echo "#  warning \"Wasted stack: $(DEF_STACK_BASE) > $(STACK_BASE)\""  >>up_mem.h
-	@echo "#endif" >>up_mem.h
-	@echo "" >>up_mem.h
-	@echo "#define UP_HEAP_BASE          $(HEAP_BASE)" >> up_mem.h
-	@echo "#define UP_HEAP_END           $(CONFIG_DRAM_END)" >> up_mem.h
+	@echo "#define UP_STACK_END           $(CONFIG_DRAM_SIZE)" >> up_mem.h
+	@echo "#define UP_STACK_BASE          (UP_STACK_END - $(CONFIG_PROC_STACK_SIZE))" >> up_mem.h
+	@echo "#define UP_HEAP1_END           UP_STACK_BASE" >> up_mem.h
+	@echo "#define UP_HEAP1_BASE          $(HEAP_BASE)" >> up_mem.h
 	@echo "" >>up_mem.h
 	@echo "#endif /* __ARCH_MEM_H */" >>up_mem.h
 
@@ -167,31 +152,46 @@ board/libboard$(LIBEXT):
 
 # This target builds the final executable
 
-pass1.ihx: up_mem.h $(HEAD_AOBJ) board/libboard$(LIBEXT)
-	$(CC) $(LDFLAGS) -L$(BOARDDIR) $(SDCCPATH) $(HEAD_AOBJ) \
-		-llibboard$(LIBEXT) $(SDCCLIBS) -o $@
+pass1.ihx: up_mem.h $(SDCCLIBDIR)/myz80.lib $(HEAD_AOBJ) board/libboard$(LIBEXT)
+	@echo "-k $(BOARDDIR)" >pass1.lnk		# Path to board library
+	@echo "-k $(SDCCLIBDIR)" >>pass1.lnk		# Path to SDCC z80 library
+	@echo "-l libboard$(LIBEXT)" >>pass1.lnk	# Name of board library
+	@for LIB in $(LINKLIBS); do \
+		echo "-l $(TOPDIR)/$$LIB" >> pass1.lnk ;\
+	done
+	@echo "-l myz80.lib" >>pass1.lnk		# Name of SDCC z80 library
+#	@echo "-m pass1.map" >>pass1.lnk		# Generate a map file
+#	@echo "-j pass1.sym" >>pass1.lnk		# Generate a symbol file
+	@echo "-i" >>pass1.lnk				# Intel hex format
+	@echo "pass1.ihx" >>pass1.lnk			# Path to head object
+	@echo "$(HEAD_AOBJ)" >>pass1.lnk		# Path to head object
+	@echo "-e" >>pass1.lnk				# End of script
+	$(LD) -f pass1.lnk
 	@rm -f up_mem.h
 	@rm -f up_allocateheap$(OBJEXT) libarch$(LIBEXT)
 	@$(MAKE) TOPDIR=$(TOPDIR) libarch$(LIBEXT)
 
-nuttx.ihx: up_mem.h $(HEAD_AOBJ)
-	$(CC) $(LDFLAGS) -L$(BOARDDIR) $(SDCCPATH) $(HEAD_AOBJ) \
-		-llibboard$(LIBEXT) $(SDCCLIBS) -o $@
+nuttx.ihx: up_mem.h $(SDCCLIBDIR)/myz80.lib $(HEAD_AOBJ)
+	@echo "-k $(BOARDDIR)" >nuttx.lnk		# Path to board library
+	@echo "-k $(SDCCLIBDIR)" >>nuttx.lnk		# Path to SDCC z80 library
+	@echo "-l libboard$(LIBEXT)" >>nuttx.lnk	# Name of board library
+	@for LIB in $(LINKLIBS); do \
+		echo "-l $(TOPDIR)/$$LIB" >> nuttx.lnk ;\
+	done
+	@echo "-l myz80.lib" >>nuttx.lnk		# Name of SDCC z80 library
+	@echo "-m nuttx.map" >>nuttx.lnk		# Generate a map file
+#	@echo "-j nuttx.sym" >>nuttx.lnk		# Generate a symbol file
+	@echo "-i" >>nuttx.lnk				# Intel hex format
+	@echo "nuttx.ihx" >>nuttx.lnk			# Path to head object
+	@echo "$(HEAD_AOBJ)" >>nuttx.lnk		# Path to head object
+	@echo "-e" >>nuttx.lnk				# End of script
+	$(LD) -f nuttx.lnk
 
 nuttx$(EXEEXT): pass1.ihx nuttx.ihx
 	@rm -f pass1.*
 	packihx nuttx.ihx > $(TOPDIR)/nuttx$(EXEEXT)
 	@cp -f nuttx.map $(TOPDIR)/.
 
-# This target builds a test program to verify interrupt context switching.  irqtest is
-# a PHONY target that just sets upt the up_irqtest build correctly
-
-up_irqtest.ihx: $(TEST_COBJS)
-	$(CC) $(LDFLAGS) -L. $(SDCCPATH) $(HEAD_AOBJ) $(TEST_COBJS) $(TESTEXTRAOBJS) $(SDCCLIBS) -o $@
-
-irqtest:
-	$(MAKE) TOPDIR=../../.. up_irqtest.ihx
-
 # Build dependencies
 
 .depend: Makefile up_mem.h chip/Make.defs $(DEPSRCS)
@@ -207,7 +207,7 @@ clean:
 	@if [ -e board/Makefile ]; then \
 		$(MAKE) -C board TOPDIR=$(TOPDIR) clean ; \
 	fi
-	rm -f libarch$(LIBEXT) up_mem.h
+	rm -f libarch$(LIBEXT) up_mem.h pass1.lnk nuttx.lnk
 	rm -f *.asm *.rel *.lst *.rst *.sym *.adb *.lnk *.map *.mem *.ihx *.hex *~
 	if [ ! -z "$(OBJEXT)" ]; then rm -f *$(OBJEXT); fi
 
diff --git a/nuttx/arch/z80/src/common/up_allocateheap.c b/nuttx/arch/z80/src/common/up_allocateheap.c
index 04e5f2d99..0c5f9fc30 100644
--- a/nuttx/arch/z80/src/common/up_allocateheap.c
+++ b/nuttx/arch/z80/src/common/up_allocateheap.c
@@ -38,11 +38,15 @@
  ****************************************************************************/
 
 #include <nuttx/config.h>
+
 #include <sys/types.h>
 #include <debug.h>
 #include <nuttx/arch.h>
+#include <nuttx/mm.h>
+
 #include "up_arch.h"
 #include "up_internal.h"
+#include "up_mem.h"
 
 /****************************************************************************
  * Private Definitions
@@ -64,16 +68,31 @@
  * Name: up_allocate_heap
  *
  * Description:
- *   The heap may be statically allocated by
- *   defining CONFIG_HEAP_BASE and CONFIG_HEAP_SIZE.  If these
- *   are not defined, then this function will be called to
- *   dynamically set aside the heap region.
+ *   The heap may be statically allocated by defining CONFIG_HEAP_BASE and
+ *   CONFIG_HEAP_SIZE.  If these are not defined, then this function will be
+ *   called to dynamically set aside the heap region.
  *
  ****************************************************************************/
 
 void up_allocate_heap(FAR void **heap_start, size_t *heap_size)
 {
+  *heap_start = (FAR void*)UP_HEAP1_BASE;
+  *heap_size = UP_HEAP1_END - UP_HEAP1_BASE;
   up_ledon(LED_HEAPALLOCATE);
-  *heap_start = (void*)(CONFIG_DRAM_SIZE - CONFIG_HEAP_SIZE);
-  *heap_size  = CONFIG_HEAP_SIZE;
 }
+
+/****************************************************************************
+ * Name: up_addregions
+ *
+ * Description:
+ *   Memory may be added in non-contiguous chunks.  Additional chunks are
+ *   added by calling this function.
+ *
+ ****************************************************************************/
+
+#if CONFIG_MM_REGIONS > 1
+void up_addregion(void)
+{
+  mm_addregion((FAR void*)UP_HEAP2_BASE, UP_HEAP2_END - UP_HEAP2_BASE);
+}
+#endif
diff --git a/nuttx/arch/z80/src/common/up_blocktask.c b/nuttx/arch/z80/src/common/up_blocktask.c
index b2d014bca..e2d405b36 100644
--- a/nuttx/arch/z80/src/common/up_blocktask.c
+++ b/nuttx/arch/z80/src/common/up_blocktask.c
@@ -57,11 +57,11 @@
  ****************************************************************************/
 
 /****************************************************************************
- * Private Funtions
+ * Private Functions
  ****************************************************************************/
 
 /****************************************************************************
- * Public Funtions
+ * Public Functions
  ****************************************************************************/
 
 /****************************************************************************
diff --git a/nuttx/arch/z80/src/common/up_copystate.c b/nuttx/arch/z80/src/common/up_copystate.c
index 8a4915181..b05ab82c3 100644
--- a/nuttx/arch/z80/src/common/up_copystate.c
+++ b/nuttx/arch/z80/src/common/up_copystate.c
@@ -58,7 +58,7 @@
  ****************************************************************************/
 
 /****************************************************************************
- * Public Funtions
+ * Public Functions
  ****************************************************************************/
 
 /****************************************************************************
diff --git a/nuttx/arch/z80/src/common/up_doirq.c b/nuttx/arch/z80/src/common/up_doirq.c
index d21cefabb..9e9105426 100644
--- a/nuttx/arch/z80/src/common/up_doirq.c
+++ b/nuttx/arch/z80/src/common/up_doirq.c
@@ -63,7 +63,7 @@
  ****************************************************************************/
 
 /****************************************************************************
- * Public Funtions
+ * Public Functions
  ****************************************************************************/
 
 void up_doirq(int irq, chipreg_t *regs)
diff --git a/nuttx/arch/z80/src/common/up_exit.c b/nuttx/arch/z80/src/common/up_exit.c
index 8784f2f78..4a4dba532 100644
--- a/nuttx/arch/z80/src/common/up_exit.c
+++ b/nuttx/arch/z80/src/common/up_exit.c
@@ -62,7 +62,7 @@
  ****************************************************************************/
 
 /****************************************************************************
- * Private Funtions
+ * Private Functions
  ****************************************************************************/
 
 /****************************************************************************
@@ -125,7 +125,7 @@ static void _up_dumponexit(FAR _TCB *tcb, FAR void *arg)
 #endif
 
 /****************************************************************************
- * Public Funtions
+ * Public Functions
  ****************************************************************************/
 
 /****************************************************************************
diff --git a/nuttx/arch/z80/src/common/up_head.asm b/nuttx/arch/z80/src/common/up_head.asm
index 272754e05..e8132e37f 100644
--- a/nuttx/arch/z80/src/common/up_head.asm
+++ b/nuttx/arch/z80/src/common/up_head.asm
@@ -52,13 +52,16 @@
 	XCPT_BC	== 14		; Saved BC register

 	XCPT_I 	== 16		; Saved I w/interrupt state in carry

 

+	; Default stack base (needs to be fixed)

+

+	STACK_BASE == 0xffff

+

 ;**************************************************************************

 ; Global symbols used

 ;**************************************************************************

 

 	.globl	_os_start		; OS entry point

-	.globl	_idle_stack		; Top of allocated stack region

-	.globl	_up_irqdecode		; Interrupt decoding logic

+	.globl	_up_decodeirq		; Interrupt decoding logic

 

 ;**************************************************************************

 ; Reset entry point

@@ -68,10 +71,10 @@
 	.org	0x0000

 

 	.globl	_os_start

-	di				 ; Disable interrupts

-	ld	SP, #_idle_stack	 ; Set stack pointer

-	im	1			 ; Set interrupt mode 1

-	jp	_os_start		 ; jump to the OS entry point

+	di				; Disable interrupts

+	ld	SP, #STACK_BASE	 	; Set stack pointer

+	im	1			; Set interrupt mode 1

+	jp	_os_start		; jump to the OS entry point

 forever:

 	jp	forever

 

@@ -113,7 +116,7 @@ forever:
 	ld	hl, #0			; Argument is the beginning of the reg structure

 	add	hl, sp

 	push	hl

-	call	_up_irqdecode		; Decode the IRQ

+	call	_up_decodeirq		; Decode the IRQ

 

 	; Restore registers.  HL points to the beginning of the reg structure to restore

 

diff --git a/nuttx/arch/z80/src/common/up_initialize.c b/nuttx/arch/z80/src/common/up_initialize.c
index a24d814dc..40205133b 100644
--- a/nuttx/arch/z80/src/common/up_initialize.c
+++ b/nuttx/arch/z80/src/common/up_initialize.c
@@ -58,6 +58,17 @@
 #undef CONFIG_ARCH_CALIBRATION
 
 /****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/* This holds a references to the current interrupt level
+ * register storage structure.  If is non-NULL only during
+ * interrupt processing.
+ */
+
+uint16 *current_regs;
+
+/****************************************************************************
  * Private Types
  ****************************************************************************/
 
diff --git a/nuttx/arch/z80/src/common/up_initialstate.c b/nuttx/arch/z80/src/common/up_initialstate.c
index 0c87aa51d..aa3090367 100644
--- a/nuttx/arch/z80/src/common/up_initialstate.c
+++ b/nuttx/arch/z80/src/common/up_initialstate.c
@@ -55,11 +55,11 @@
  ****************************************************************************/
 
 /****************************************************************************
- * Private Funtions
+ * Private Functions
  ****************************************************************************/
 
 /****************************************************************************
- * Public Funtions
+ * Public Functions
  ****************************************************************************/
 
 /****************************************************************************
diff --git a/nuttx/arch/z80/src/common/up_internal.h b/nuttx/arch/z80/src/common/up_internal.h
index e3da89213..89e334b36 100644
--- a/nuttx/arch/z80/src/common/up_internal.h
+++ b/nuttx/arch/z80/src/common/up_internal.h
@@ -110,6 +110,7 @@ extern int up_restoreusercontext(chipreg_t *regs);
 extern FAR chipreg_t *up_decodeirq(FAR chipreg_t *regs);
 extern void up_irqinitialize(void);
 extern int  up_timerisr(int irq, FAR chipreg_t *regs);
+extern void up_lowputc(char ch) __naked;
 
 /* Defined in up_doirq.c */
 
@@ -119,12 +120,6 @@ extern void up_doirq(int irq, FAR chipreg_t *regs);
 
 extern void up_sigdeliver(void);
 
-#ifdef CONFIG_DEBUG
-extern void up_lowputc(char ch);
-#else
-# define up_lowputc(ch)
-#endif
-
 /* Defined in up_allocateheap.c */
 
 #if CONFIG_MM_REGIONS > 1
diff --git a/nuttx/arch/z80/src/common/up_irq.c b/nuttx/arch/z80/src/common/up_irq.c
new file mode 100644
index 000000000..5f8897a41
--- /dev/null
+++ b/nuttx/arch/z80/src/common/up_irq.c
@@ -0,0 +1,104 @@
+/****************************************************************************
+ * common/up_irq.c
+ *
+ *   Copyright (C) 2007, 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.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/irq.h>
+
+#include "up_internal.h"
+
+/****************************************************************************
+ * Private Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: irqsave
+ *
+ * Description:
+ *   Disable all interrupts; return previous interrupt state
+ *
+ ****************************************************************************/
+
+irqstate_t irqsave(void) __naked
+{
+  _asm
+	ld	a, i		; AF Carry bit holds interrupt state
+	di			; Interrupts are disabled
+	push	af		; Return AF in HL
+	pop	hl		;
+	ret			;
+  _endasm;
+}
+
+/****************************************************************************
+ * Name: irqrestore
+ *
+ * Description:
+ *   Restore previous interrupt state
+ *
+ ****************************************************************************/
+
+void irqrestore(irqstate_t flags) __naked
+{
+  _asm
+	pop	hl		; HL = return address
+	pop	af		; AF Carry bit hold interrupt state
+	jr	nc, statedisable
+	ei
+	ret
+statedisable:
+	di
+	ret
+  _endasm;
+}
diff --git a/nuttx/arch/z80/src/common/up_releasepending.c b/nuttx/arch/z80/src/common/up_releasepending.c
index 8bf0bf798..3b2b119a3 100644
--- a/nuttx/arch/z80/src/common/up_releasepending.c
+++ b/nuttx/arch/z80/src/common/up_releasepending.c
@@ -58,11 +58,11 @@
  ****************************************************************************/
 
 /****************************************************************************
- * Private Funtions
+ * Private Functions
  ****************************************************************************/
 
 /****************************************************************************
- * Public Funtions
+ * Public Functions
  ****************************************************************************/
 
 /****************************************************************************
diff --git a/nuttx/arch/z80/src/common/up_reprioritizertr.c b/nuttx/arch/z80/src/common/up_reprioritizertr.c
index e90bd7186..b5961d92d 100644
--- a/nuttx/arch/z80/src/common/up_reprioritizertr.c
+++ b/nuttx/arch/z80/src/common/up_reprioritizertr.c
@@ -58,11 +58,11 @@
  ****************************************************************************/
 
 /****************************************************************************
- * Private Funtions
+ * Private Functions
  ****************************************************************************/
 
 /****************************************************************************
- * Public Funtions
+ * Public Functions
  ****************************************************************************/
 
 /****************************************************************************
diff --git a/nuttx/arch/z80/src/common/up_restoreusercontext.asm b/nuttx/arch/z80/src/common/up_restoreusercontext.asm
index 093d18b7c..a8acba64a 100644
--- a/nuttx/arch/z80/src/common/up_restoreusercontext.asm
+++ b/nuttx/arch/z80/src/common/up_restoreusercontext.asm
@@ -1,5 +1,5 @@
 ;**************************************************************************

-; arch/z80/src/common/up_restoreusercontext.asm

+; common/up_restoreusercontext.asm

 ;

 ;   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.

 ;   Author: Gregory Nutt <spudmonkey@racsa.co.cr>

@@ -35,23 +35,22 @@
 

 	; Register save area layout

 

-	XCPT_I	==  0		; Saved I w/interrupt state in carry

-	XCPT_AF	==  2		; Saved AF register

-	XCPT_BC	==  4		; Saved BC register

-	XCPT_DE	==  6		; Saved DE register

-	XCPT_HL	==  8		; Saved HL register

-	XCPT_IX	== 10		; Saved IX register

-	XCPT_IY	== 12		; Saved IY register

-	XCPT_SP	== 14		; Offset to SP at time of interrupt

-	XCPT_PC	== 16		; Offset to PC at time of interrupt

+	.globl	XCPT_I		; Saved I w/interrupt state in carry

+	.globl	XCPT_AF		; Saved AF register

+	.globl	XCPT_BC		; Saved BC register

+	.globl	XCPT_DE		; Saved DE register

+	.globl	XCPT_HL		; Saved HL register

+	.globl	XCPT_IX		; Saved IX register

+	.globl	XCPT_IY		; Saved IY register

+	.globl	XCPT_SP		; Offset to SP at time of interrupt

+	.globl	XCPT_PC		; Offset to PC at time of interrupt

 

 ;**************************************************************************

 ; up_restoreusercontext

 ;**************************************************************************

 

-	.org   0x0038			; Int mode 1

         .area   TEXT    (ABS,OVR)

-up_restoreusercontext:

+_up_restoreusercontext:

 	; On entry, stack contains return address (not used), then address

 	; of the register save structure

 

@@ -90,7 +89,7 @@ up_restoreusercontext:
 	; Restore interrupt state

 

 	ex	af, af'			; Recover interrupt state

-	jnc	noinrestore		; No carry, IFF2=0, means disabled

+	jr	nc, noinrestore		; No carry, IFF2=0, means disabled

 	ex	af, af'			; Restore AF (before enabling interrupts)

 	ei				; yes

 	ret

diff --git a/nuttx/arch/z80/src/common/up_saveusercontext.asm b/nuttx/arch/z80/src/common/up_saveusercontext.asm
index 9d25a7800..5514f9e63 100644
--- a/nuttx/arch/z80/src/common/up_saveusercontext.asm
+++ b/nuttx/arch/z80/src/common/up_saveusercontext.asm
@@ -1,5 +1,5 @@
 ;*************************************************************************
-; common/up_saveusercontext.S
+; common/up_saveusercontext.asm
 ;
 ;   Copyright (C) 2007 Gregory Nutt. All rights reserved.
 ;   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
@@ -39,15 +39,15 @@
 
 	; Register save area layout
 
-	XCPT_I		==  0	; Saved I w/interrupt state in carry
-	XCPT_AF		==  2	; Saved AF register
-	XCPT_BC		==  4	; Saved BC register
-	XCPT_DE		==  6	; Saved DE register
-	XCPT_HL		==  8	; Saved HL register
-	XCPT_IX		== 10	; Saved IX register
-	XCPT_IY		== 12	; Saved IY register
-	XCPT_SP		== 14	; Offset to SP at time of interrupt
-	XCPT_PC		== 16	; Offset to PC at time of interrupt
+	.globl	XCPT_I		; Saved I w/interrupt state in carry
+	.globl	XCPT_AF		; Saved AF register
+	.globl	XCPT_BC		; Saved BC register
+	.globl	XCPT_DE		; Saved DE register
+	.globl	XCPT_HL		; Saved HL register
+	.globl	XCPT_IX		; Saved IX register
+	.globl	XCPT_IY		; Saved IY register
+	.globl	XCPT_SP		; Offset to SP at time of interrupt
+	.globl	XCPT_PC		; Offset to PC at time of interrupt
 
 	; Stack frame
 
@@ -63,7 +63,7 @@
 ;*************************************************************************
 
 	.area	TEXT	(ABS,OVR)
-up_saveusercontext:
+_up_saveusercontext:
 	; Set up a stack frame
 
 	push	ix			; Save IX and IY
@@ -73,10 +73,10 @@ up_saveusercontext:
 
 	; Fetch the address of the save area
 
-	ld	l, FRAME_REGS(ix)	; HL = save area address
-	ld	h, FRAME_REGS+1(ix)	;
+	ld	e, FRAME_REGS(ix)	; HL = save area address
+	ld	d, FRAME_REGS+1(ix)	;
 	ld	iy, #0
-	add	iy, hl			; IY = save area address
+	add	iy, de			; IY = save area address
 
 	; Then save the registers
 
@@ -85,13 +85,13 @@ up_saveusercontext:
 	ld	a, i			; Get interrupt state
 	push	af
 	pop	hl
-	ld	(iy+XCPT_I), l		; Offset 0: I w/interrupt state in carry
-	ld	(iy+XCPT_I+1), h
+	ld	XCPT_I(iy), l		; Offset 0: I w/interrupt state in carry
+	ld	XCPT_I+1(iy), h
 
 	; Save BC at offset 1
 
-	ld	(iy+XCPT_BC), c		; Offset 1: BC
-	ld	(iy+XCPT_BC+1), b
+	ld	XCPT_BC(iy), c		; Offset 1: BC
+	ld	XCPT_BC+1(iy), b
 
 	; DE is not preserved (offset 2)
 
@@ -99,29 +99,29 @@ up_saveusercontext:
 
 	ld	l, FRAME_IX(ix)		; HL = Saved alue of IX
 	ld	h, FRAME_IX+1(ix)	;
-	ld	(iy+XCPT_IX), l		; Offset 3: IX
-	ld	(iy+XCPT_IX+1), h	;
+	ld	XCPT_IX(iy), l		; Offset 3: IX
+	ld	XCPT_IX+1(iy), h	;
 
 	; Save IY at offset 4
 
 	ld	l, FRAME_IY(ix)		; HL = Saved value of IY
 	ld	h, FRAME_IY+1(ix)	;
-	ld	(iy+XCPT_IY), l		; Offset 4: IY
-	ld	(iy+XCPT_IY+1), h
+	ld	XCPT_IY(iy), l		; Offset 4: IY
+	ld	XCPT_IY+1(iy), h
 
 	; Save that stack pointer as it would be upon return in offset 5
 
 	ld	hl, #SP_OFFSET		; Value of stack pointer on return
 	add	hl, sp
-	ld	(iy+XCPT_SP), l		; Offset 5 SP
-	ld	(iy+XCPT_SP+1), h
+	ld	XCPT_SP(iy), l		; Offset 5 SP
+	ld	XCPT_SP+1(iy), h
 
 	; HL is saved as the value 1 at offset 6
 
 	xor	a			; A = 0
-	ld	(iy+XCPT_HL+1), a	; Offset 2: HL on return (=1)
+	ld	XCPT_HL+1(iy), a	; Offset 2: HL on return (=1)
 	inc	a			; A = 1
-	ld	(iy+XCPT_HL), a		;
+	ld	XCPT_HL(iy), a		;
 
 	; AF is not preserved (offset 7)
 
@@ -129,8 +129,8 @@ up_saveusercontext:
 
 	ld	l, FRAME_RET(ix)	; HL = Saved return address
 	ld	h, FRAME_RET+1(ix)	;
-	ld	(iy+XCPT_PC), l		; Offset 8: PC
-	ld	(iy+XCPT_PC+1), h
+	ld	XCPT_PC(iy), l		; Offset 8: PC
+	ld	XCPT_PC+1(iy), h
 
 	; Return the value 0
 
diff --git a/nuttx/arch/z80/src/common/up_schedulesigaction.c b/nuttx/arch/z80/src/common/up_schedulesigaction.c
index 90039df17..f22144df4 100644
--- a/nuttx/arch/z80/src/common/up_schedulesigaction.c
+++ b/nuttx/arch/z80/src/common/up_schedulesigaction.c
@@ -55,11 +55,11 @@
  ************************************************************/
 
 /************************************************************
- * Private Funtions
+ * Private Functions
  ************************************************************/
 
 /************************************************************
- * Public Funtions
+ * Public Functions
  ************************************************************/
 
 /************************************************************
diff --git a/nuttx/arch/z80/src/common/up_sigdeliver.c b/nuttx/arch/z80/src/common/up_sigdeliver.c
index f8f0c79de..0877fffe3 100644
--- a/nuttx/arch/z80/src/common/up_sigdeliver.c
+++ b/nuttx/arch/z80/src/common/up_sigdeliver.c
@@ -60,7 +60,7 @@
  ************************************************************/
 
 /************************************************************
- * Public Funtions
+ * Public Functions
  ************************************************************/
 
 /************************************************************
diff --git a/nuttx/arch/z80/src/common/up_unblocktask.c b/nuttx/arch/z80/src/common/up_unblocktask.c
index 8934c700c..93bfdf472 100644
--- a/nuttx/arch/z80/src/common/up_unblocktask.c
+++ b/nuttx/arch/z80/src/common/up_unblocktask.c
@@ -59,11 +59,11 @@
  ****************************************************************************/
 
 /****************************************************************************
- * Private Funtions
+ * Private Functions
  ****************************************************************************/
 
 /****************************************************************************
- * Public Funtions
+ * Public Functions
  ****************************************************************************/
 
 /****************************************************************************
diff --git a/nuttx/arch/z80/src/z80/Make.defs b/nuttx/arch/z80/src/z80/Make.defs
index 80d5c7c0b..05dc8cd56 100644
--- a/nuttx/arch/z80/src/z80/Make.defs
+++ b/nuttx/arch/z80/src/z80/Make.defs
@@ -39,7 +39,7 @@ CMN_ASRCS	= up_saveusercontext.asm up_restoreusercontext.asm
 CMN_CSRCS	= up_initialize.c up_allocateheap.c up_initialstate.c \
 		  up_createstack.c up_releasestack.c up_interruptcontext.c \
 		  up_blocktask.c  up_unblocktask.c up_exit.c up_releasepending.c \
-		  up_reprioritizertr.c up_copystate.c up_idle.c \
+		  up_reprioritizertr.c up_copystate.c up_irq.c up_idle.c \
 		  up_assert.c up_mdelay.c up_udelay.c \
 		  up_registerdump.c up_usestack.c \
 
diff --git a/nuttx/configs/z80sim/Make.defs b/nuttx/configs/z80sim/Make.defs
index 73ba579b7..3ac3135bc 100644
--- a/nuttx/configs/z80sim/Make.defs
+++ b/nuttx/configs/z80sim/Make.defs
@@ -57,18 +57,10 @@ AR			= sdcclib -a
 CFLAGS			= $(ARCHWARNINGS) $(ARCHOPTIMIZATION) \
 			  $(ARCHCPUFLAGS) $(ARCHINCLUDES) $(ARCHDEFINES)
 CPPFLAGS		= $(ARCHINCLUDES) $(ARCHDEFINES)
-ASFLAGS			= 
+ASFLAGS			= -x -a -l -o -s
 
 SDCCLIBDIR		= /usr/local/share/sdcc/lib/z80
-SDCCPATH		= -L$(SDCCLIBDIR)
-SDCCLIBS		= -lz80.lib
-
-IRAM_SIZE		= 0x100
-DEF_STACK_BASE		= 0x24
-LDFLAGS			= --model-large --nostdlib \
-			  --data-loc $(DEF_STACK_BASE) --iram-size $(IRAM_SIZE) \
-			  --code-loc 0x2100 --code-size 0x5f40 \
-			  --xram-loc $(IRAM_SIZE) --xram-size 0x1f00
+SDCCLIB			= z80.lib
 
 ASMEXT			= .asm
 OBJEXT			= .o
diff --git a/nuttx/configs/z80sim/defconfig b/nuttx/configs/z80sim/defconfig
index a806bfc6b..0603818d0 100644
--- a/nuttx/configs/z80sim/defconfig
+++ b/nuttx/configs/z80sim/defconfig
@@ -86,7 +86,7 @@ CONFIG_DRAM_SIZE=65536
 CONFIG_EXAMPLE=ostest
 CONFIG_DEBUG=n
 CONFIG_DEBUG_VERBOSE=n
-CONFIG_MM_REGIONS=2
+CONFIG_MM_REGIONS=1
 CONFIG_ARCH_LOWPUTC=y
 CONFIG_RR_INTERVAL=0
 CONFIG_SCHED_INSTRUMENTATION=n
diff --git a/nuttx/configs/z80sim/src/Makefile b/nuttx/configs/z80sim/src/Makefile
index 24226f2f9..d1f495608 100644
--- a/nuttx/configs/z80sim/src/Makefile
+++ b/nuttx/configs/z80sim/src/Makefile
@@ -36,11 +36,11 @@
 -include $(TOPDIR)/Make.defs
 
 MKDEP 		= $(TOPDIR)/tools/mkdeps.sh
-CFLAGS		+= -I$(TOPDIR)/sched
+CFLAGS		+= -I$(TOPDIR)/sched -I$(TOPDIR)/arch/z80/src/common -I$(TOPDIR)/arch/z80/src/z80
 
-ASRCS		= z80_lowputc$(ASMEXT) 
+ASRCS		= 
 AOBJS		= $(ASRCS:$(ASMEXT)=$(OBJEXT))
-CSRCS		= z80_decodeirq.c z80_irq.c z80_serial.c z80_timerisr.c
+CSRCS		= z80_decodeirq.c z80_irq.c z80_serial.c z80_timerisr.c z80_lowputc.c
 COBJS		= $(CSRCS:.c=$(OBJEXT))
 
 SRCS		= $(ASRCS) $(CSRCS)
diff --git a/nuttx/configs/z80sim/src/z80_decodeirq.c b/nuttx/configs/z80sim/src/z80_decodeirq.c
index d4faf0f89..c1acfffb9 100644
--- a/nuttx/configs/z80sim/src/z80_decodeirq.c
+++ b/nuttx/configs/z80sim/src/z80_decodeirq.c
@@ -1,5 +1,5 @@
 /********************************************************************************
- * z80/z80_decodeirq.c
+ * board/z80_decodeirq.c
  *
  *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
@@ -38,12 +38,13 @@
  ********************************************************************************/
 
 #include <nuttx/config.h>
+
 #include <sys/types.h>
 #include <nuttx/irq.h>
 #include <nuttx/arch.h>
 #include <assert.h>
 #include <debug.h>
-#include "up_arch.h"
+
 #include "os_internal.h"
 #include "up_internal.h"
 
@@ -64,56 +65,37 @@
  ********************************************************************************/
 
 /********************************************************************************
- * Public Funtions
+ * Public Functions
  ********************************************************************************/
 
-void up_decodeirq(uint16* regs)
+FAR chipreg_t *up_decodeirq(FAR chipreg_t *regs)
 {
 #ifdef CONFIG_SUPPRESS_INTERRUPTS
+
   lib_lowprintf("Unexpected IRQ\n");
   current_regs = regs;
   PANIC(OSERR_ERREXCEPTION);
-#else
-  /* Decode the interrupt.  First, fetch the interrupt id register. */
-
-  uint16 irqentry = getreg16(DM320_INTC_IRQENTRY0);
-
-  /* The irqentry value is an offset into a table.  Zero means no interrupt. */
+  return NULL; /* Won't get here */
 
-  if (irqentry != 0)
-    {
-      /* If non-zero, then we can map the table offset into an IRQ number */
-
-      int irq = (irqentry >> 2) - 1;
-
-      /* Verify that the resulting IRQ number is valie */
-
-      if ((unsigned)irq < NR_IRQS)
-        {
-          /* Mask and acknowledge the interrupt */
-
-          up_maskack_irq(irq);
+#else
 
-          /* Current regs non-zero indicates that we are processing an interrupt;
-           * current_regs is also used to manage interrupt level context switches.
-           */
+  /* Current regs non-zero indicates that we are processing an interrupt;
+   * current_regs is also used to manage interrupt level context switches.
+   */
 
-          current_regs = regs;
+  current_regs = regs;
 
-          /* Deliver the IRQ */
+  /* Deliver the IRQ -- the simulation supports only timer interrupts */
 
-          irq_dispatch(irq, regs);
+  irq_dispatch(Z80_IRQ_SYSTIMER, regs);
 
-          /* Indicate that we are no long in an interrupt handler */
+  /* If a context switch occurred, current_regs will hold the new context */
 
-          current_regs = NULL;
+  regs = current_regs;
 
-          /* Unmask the last interrupt (global interrupts are still
-           * disabled.
-           */
+  /* Indicate that we are no long in an interrupt handler */
 
-          up_enable_irq(irq);
-        }
-    }
+  current_regs = NULL;
+  return regs;
 #endif
 }
diff --git a/nuttx/configs/z80sim/src/z80_irq.c b/nuttx/configs/z80sim/src/z80_irq.c
index 3c3443663..b6e81b32e 100644
--- a/nuttx/configs/z80sim/src/z80_irq.c
+++ b/nuttx/configs/z80sim/src/z80_irq.c
@@ -1,7 +1,7 @@
 /****************************************************************************
- * z80/z80_irq.c
+ * board/z80_irq.c
  *
- *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -14,7 +14,7 @@
  *    notice, this list of conditions and the following disclaimer in
  *    the documentation and/or other materials provided with the
  *    distribution.
- * 3. Neither the name Gregory Nutt nor the names of its contributors may be
+ * 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.
  *
@@ -38,8 +38,10 @@
  ****************************************************************************/
 
 #include <nuttx/config.h>
+
 #include <sys/types.h>
 #include <nuttx/irq.h>
+
 #include "up_arch.h"
 #include "os_internal.h"
 #include "up_internal.h"
@@ -52,8 +54,6 @@
  * Public Data
  ****************************************************************************/
 
-uint32 *current_regs;
-
 /****************************************************************************
  * Private Data
  ****************************************************************************/
@@ -63,7 +63,7 @@ uint32 *current_regs;
  ****************************************************************************/
 
 /****************************************************************************
- * Public Funtions
+ * Public Functions
  ****************************************************************************/
 
 /****************************************************************************
diff --git a/nuttx/configs/z80sim/src/z80_lowputc.c b/nuttx/configs/z80sim/src/z80_lowputc.c
new file mode 100644
index 000000000..1c8abb2a4
--- /dev/null
+++ b/nuttx/configs/z80sim/src/z80_lowputc.c
@@ -0,0 +1,101 @@
+/********************************************************************************
+ * board/z80_lowputc.c
+ *
+ *   Copyright (C) 2007, 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.
+ *
+ ********************************************************************************/
+
+/********************************************************************************
+ * Included Files
+ ********************************************************************************/
+
+#include <nuttx/config.h>
+#include <sys/types.h>
+#include <nuttx/irq.h>
+#include <nuttx/arch.h>
+#include <assert.h>
+#include <debug.h>
+#include "up_arch.h"
+#include "os_internal.h"
+#include "up_internal.h"
+
+/********************************************************************************
+ * Definitions
+ ********************************************************************************/
+
+/********************************************************************************
+ * Public Data
+ ********************************************************************************/
+
+/********************************************************************************
+ * Private Data
+ ********************************************************************************/
+
+/********************************************************************************
+ * Private Functions
+ ********************************************************************************/
+
+/********************************************************************************
+ * Public Functions
+ ********************************************************************************/
+
+/********************************************************************************
+ * Name: up_lowputc
+ *
+ * Data sent to port 0xbe are echoed on stdout by the simulation
+ *
+ ********************************************************************************/
+
+void up_lowputc(char ch) __naked
+{
+  _asm
+	ld	a, #2(sp)
+	out	#0xbe, a
+	ret
+  _endasm;
+}
+
+/********************************************************************************
+ * Name: up_lowgetc
+ *
+ * Data from stdin can be received on port 0xbe in the simulation
+ *
+ ********************************************************************************/
+
+char up_lowgetc(void) __naked
+{
+  _asm
+	in	#0xbe, a
+	ld	l, a
+	ld	h, #0
+	ret
+  _endasm;
+}
diff --git a/nuttx/configs/z80sim/src/z80_serial.c b/nuttx/configs/z80sim/src/z80_serial.c
index 73bba4932..dbca1b78e 100644
--- a/nuttx/configs/z80sim/src/z80_serial.c
+++ b/nuttx/configs/z80sim/src/z80_serial.c
@@ -1,5 +1,5 @@
 /****************************************************************************
- * z80/z80_serial.c
+ * board/z80_serial.c
  *
  *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
@@ -41,7 +41,6 @@
 
 #include <sys/types.h>
 #include <unistd.h>
-#include <semaphore.h>
 #include <string.h>
 #include <errno.h>
 #include <debug.h>
@@ -282,7 +281,7 @@ static boolean up_txfifoempty(struct uart_dev_s *dev)
 }
 
 /****************************************************************************
- * Public Funtions
+ * Public Functions
  ****************************************************************************/
 
 /****************************************************************************
diff --git a/nuttx/configs/z80sim/src/z80_timerisr.c b/nuttx/configs/z80sim/src/z80_timerisr.c
index 603a66c91..e56678d13 100644
--- a/nuttx/configs/z80sim/src/z80_timerisr.c
+++ b/nuttx/configs/z80sim/src/z80_timerisr.c
@@ -1,7 +1,7 @@
-/************************************************************
- * dm320/dm320_timerisr.c
+/****************************************************************************
+ * board/z80_timerisr.c
  *
- *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -14,7 +14,7 @@
  *    notice, this list of conditions and the following disclaimer in
  *    the documentation and/or other materials provided with the
  *    distribution.
- * 3. Neither the name Gregory Nutt nor the names of its contributors may be
+ * 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.
  *
@@ -31,89 +31,48 @@
  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  *
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Included Files
- ************************************************************/
+ ****************************************************************************/
 
 #include <nuttx/config.h>
+
 #include <sys/types.h>
 #include <debug.h>
+
 #include <nuttx/arch.h>
+
 #include "clock_internal.h"
 #include "up_internal.h"
-#include "up_arch.h"
 
-/************************************************************
+/****************************************************************************
  * Definitions
- ************************************************************/
+ ****************************************************************************/
 
-/* DM320 Timers
- *
- * Each of the general-purpose timers can run in one of two modes:  one-
- * shot mode and free-run mode.  In one-shot mode, an interrupt only 
- * occurs once and then the timer must be explicitly reset to begin the 
- * timing operation again.  In free-run mode, when the timer generates an 
- * interrupt, the timer counter is automatically reloaded to start the count 
- * operation again.  Use the bit field MODE in TMMDx to configure the 
- * timer for one-shot more or free-run mode. The bit field MODE in TMMDx
- * also allows you to stop the timer.
- * 
- * Either the ARM clock divided by 2 (CLK_ARM/2) or an external clock 
- * connected to the M27XI pin can be selected as the clock source of the 
- * timer.
- *
- * The actual clock frequency used in the timer count operation is the input 
- * clock divided by: 1 plus the value set in the bit field PRSCL of the 
- * register TMPRSCLx (10 bits).  The timer expires when it reaches the 
- * value set in the bit field DIV of the register TMDIVx (16 bits) plus 1. 
- * PRSCL+1 is the source clock frequency divide factor and DIV+1 is the 
- * timer count value.  The frequency of a timer interrupt is given by the 
- * following equation:
- *
- * Interrupt Frequency = (Source Clock Frequency) / (PRSCL+1) / (DIV+1)
- */
-
-/* System Timer
- *
- * Timer0 is dedicated as the system timer.  The rate of system timer
- * interrupts is assumed to to 10MS per tick / 100Hz. The following
- * register settings are used for timer 0
- *
- * System clock formula:
- *   Interrupt Frequency = (Source Clock Frequency) / (PRSCL+1) / (DIV+1)
- *   Source Clock Frequency = 27MHz  (PLL clock)
- *   DIV                    = 26,999 (Yields 1Khz timer clock)
- *   PRSCL                  = 9      (Produces 100Hz interrupts)
- */
-
-#define DM320_TMR0_MODE  DM320_TMR_MODE_FREERUN /* Free running */
-#define DM320_TMR0_DIV   26999                  /* (see above) */
-#define DM320_TMR0_PRSCL 9                      /* (see above) */
-
-/************************************************************
+/****************************************************************************
  * Private Types
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Private Function Prototypes
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Global Functions
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Function:  up_timerisr
  *
  * Description:
- *   The timer ISR will perform a variety of services for
- *   various portions of the systems.
+ *   The timer ISR will perform a variety of services for various portions of
+ *   the system.
  *
- ************************************************************/
+ ****************************************************************************/
 
-int up_timerisr(int irq, uint32 *regs)
+int up_timerisr(int irq, FAR chipreg_t *regs)
 {
    /* Process timer interrupt */
 
@@ -121,33 +80,16 @@ int up_timerisr(int irq, uint32 *regs)
    return 0;
 }
 
-/************************************************************
+/****************************************************************************
  * Function:  up_timerinit
  *
  * Description:
- *   This function is called during start-up to initialize
- *   the timer interrupt.
+ *   This function is called during start-up to initialize the timer
+ *   interrupt.
  *
- ************************************************************/
+ ****************************************************************************/
 
 void up_timerinit(void)
 {
-  up_disable_irq(DM320_IRQ_SYSTIMER);
-
-  /* Start timer0 running so that an interrupt is generated at
-   * the rate MSEC_PER_TICK.
-   */
-
-  putreg16(DM320_TMR0_PRSCL, DM320_TIMER0_TMPRSCL); /* Timer 0 Prescalar */
-  putreg16(DM320_TMR0_DIV, DM320_TIMER0_TMDIV);     /* Timer 0 Divisor (count) */
-
-  /* Start the timer */
-
-  putreg16(DM320_TMR0_MODE, DM320_TIMER0_TMMD); /* Timer 0 Mode */
-
-  /* Attach and enable the timer interrupt */
-
-  irq_attach(DM320_IRQ_SYSTIMER, (xcpt_t)up_timerisr);
-  up_enable_irq(DM320_IRQ_SYSTIMER);
 }