Import of z80 target

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@455 42af7a65-404d-4744-a932-0658087f49c3

12 files changed, 1285 insertions, 0 deletions

diff --git a/nuttx/configs/z80sim/Make.defs b/nuttx/configs/z80sim/Make.defs
new file mode 100644
index 000000000..73ba579b7
--- /dev/null
+++ b/nuttx/configs/z80sim/Make.defs
@@ -0,0 +1,83 @@
+############################################################################
+# Make.defs
+#
+#   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 Gregory Nutt 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.
+#
+############################################################################
+
+include ${TOPDIR}/.config
+
+ifeq ("${CONFIG_DEBUG}","y")
+  ARCHOPTIMIZATION	= --debug
+else
+  ARCHOPTIMIZATION	=
+endif
+
+ARCHCPUFLAGS		= -mz80 --stack-auto --int-long-reent --float-reent
+ARCHPICFLAGS		=
+ARCHWARNINGS		=
+ARCHDEFINES		=
+ARCHINCLUDES		= -I. -I$(TOPDIR)/include
+
+CROSSDEV		=
+CC			= sdcc
+CPP			= sdcpp
+LD			= link-z80
+AS			= as-z80
+AR			= sdcclib -a
+
+CFLAGS			= $(ARCHWARNINGS) $(ARCHOPTIMIZATION) \
+			  $(ARCHCPUFLAGS) $(ARCHINCLUDES) $(ARCHDEFINES)
+CPPFLAGS		= $(ARCHINCLUDES) $(ARCHDEFINES)
+ASFLAGS			= 
+
+SDCCLIBDIR		= /usr/local/share/sdcc/lib/z80
+SDCCPATH		= -L$(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
+
+ASMEXT			= .asm
+OBJEXT			= .o
+LIBEXT			= .lib
+EXEEXT			= .hex
+
+HOSTCC			= gcc
+HOSTINCLUDES		= -I.
+HOSTCFLAGS		= -Wall -wstrict-prototypes -Wshadow -g -pipe
+HOSTLDFLAGS		=
+
+
diff --git a/nuttx/configs/z80sim/README.txt b/nuttx/configs/z80sim/README.txt
new file mode 100644
index 000000000..50be916e1
--- /dev/null
+++ b/nuttx/configs/z80sim/README.txt
@@ -0,0 +1,20 @@
+pjrc-8051 README
+^^^^^^^^^^^^^^^^
+
+This port uses a primitive, simulated Z80 and the SDCC toolchain.
+
+The SDCC toolchain is available from http://sdcc.sourceforge.net/.  All
+testing has been performed using verison 2.6.0 of the SDDC toolchain.
+
+Building the SDCC toolchain
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The SDCC toolchain is built with the standard configure/make/make install
+sequence.  However, some special actions are required to generate libraries
+compatible with this build.  First start with the usual steps
+
+  download
+  unpack
+  cd sdcc
+  ./configure
+  make
diff --git a/nuttx/configs/z80sim/defconfig b/nuttx/configs/z80sim/defconfig
new file mode 100644
index 000000000..a806bfc6b
--- /dev/null
+++ b/nuttx/configs/z80sim/defconfig
@@ -0,0 +1,289 @@
+############################################################
+# defconfig
+#
+#   Copyright (C) 2007 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 Gregory Nutt 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.
+#
+############################################################
+#
+# Architecture selection
+#
+# CONFIG_ARCH - identifies the arch subdirectory and, hence, the
+#   processor architecture.
+# CONFIG_ARCH_8051 - Set if processor is 8051 family
+# CONFIG_ARCH_8052 = Set if processor is 8052 family
+# CONFIG_ARCH_BOARD - identifies the configs subdirectory and, hence,
+#   the board that supports the particular chip or SoC.
+# CONFIG_ARCH_BOARD_name - for use in C code
+# CONFIG_DRAM_SIZE - Describes the installed DRAM.
+#
+CONFIG_ARCH=z80
+CONFIG_ARCH_Z80=y
+CONFIG_ARCH_CHIP=z80
+CONFIG_ARCH_CHIP_Z80=1
+CONFIG_ARCH_BOARD=z80sim
+CONFIG_DRAM_SIZE=65536
+
+#
+# General OS setup
+#
+# CONFIG_EXAMPLE - identifies the subdirectory in examples
+#   that will be used in the build
+# CONFIG_DEBUG - enables built-in debug options
+# CONFIG_DEBUG_VERBOSE - enables verbose debug output
+# CONFIG_MM_REGIONS - If the architecture includes multiple
+#   regions of memory to allocate from, this specifies the
+#   number of memory regions that the memory manager must
+#   handle and enables the API mm_addregion(start, end);
+# CONFIG_HAVE_LOWPUTC - architecture supports low-level, boot
+#   time console output
+# CONFIG_TICKS_PER_MSEC - The default system timer is 100Hz
+#   or TICKS_PER_MSEC=10.  This setting may be defined to
+#   inform NuttX that the processor hardware is providing
+#   system timer interrupts at some interrupt interval other
+#   than 10 msec.
+# CONFIG_RR_INTERVAL - The round robin timeslice will be set
+#   this number of milliseconds;  Round robin scheduling can
+#   be disabled by setting this value to zero.
+# CONFIG_SCHED_INSTRUMENTATION - enables instrumentation in 
+#   scheduler to monitor system performance
+# CONFIG_TASK_NAME_SIZE - Spcifies that maximum size of a
+#   task name to save in the TCB.  Useful if scheduler
+#   instrumentation is selected.  Set to zero to disable.
+# CONFIG_JULIAN_TIME - Enables Julian time conversions
+# CONFIG_START_YEAR, CONFIG_START_MONTH, CONFIG_START_DAY -
+#   Used to initialize the internal time logic.
+# CONFIG_DEV_CONSOLE - Set if architecture-specific logic
+#   provides /dev/console.  Enables stdout, stderr, stdin.
+#
+CONFIG_EXAMPLE=ostest
+CONFIG_DEBUG=n
+CONFIG_DEBUG_VERBOSE=n
+CONFIG_MM_REGIONS=2
+CONFIG_ARCH_LOWPUTC=y
+CONFIG_RR_INTERVAL=0
+CONFIG_SCHED_INSTRUMENTATION=n
+CONFIG_TASK_NAME_SIZE=0
+CONFIG_START_YEAR=2007
+CONFIG_START_MONTH=2
+CONFIG_START_DAY=21
+CONFIG_JULIAN_TIME=n
+CONFIG_DEV_CONSOLE=n
+
+#
+# The following can be used to disable categories of
+# APIs supported by the OS.  If the compiler supports
+# weak functions, then it should not be necessary to
+# disable functions unless you want to restrict usage
+# of those APIs.
+#
+# There are certain dependency relationships in these
+# features.
+#
+# o mq_notify logic depends on signals to awaken tasks
+#   waiting for queues to become full or empty.
+# o pthread_condtimedwait() depends on signals to wake
+#   up waiting tasks.
+#
+CONFIG_DISABLE_CLOCK=y
+CONFIG_DISABLE_POSIX_TIMERS=y
+CONFIG_DISABLE_PTHREAD=y
+CONFIG_DISABLE_SIGNALS=y
+CONFIG_DISABLE_MQUEUE=y
+CONFIG_DISABLE_MOUNTPOINT=y
+CONFIG_DISABLE_ENVIRON=y
+
+#
+# Misc libc settings
+#
+# CONFIG_NOPRINTF_FIELDWIDTH - sprintf-related logic is a
+#   little smaller if we do not support fieldwidthes
+#
+CONFIG_NOPRINTF_FIELDWIDTH=y
+
+#
+# Allow for architecture optimized implementations
+#
+# The architecture can provide optimized versions of the
+# following to improve sysem performance
+#
+CONFIG_ARCH_MEMCPY=n
+CONFIG_ARCH_MEMCMP=n
+CONFIG_ARCH_MEMMOVE=n
+CONFIG_ARCH_MEMSET=n
+CONFIG_ARCH_STRCMP=n
+CONFIG_ARCH_STRCPY=n
+CONFIG_ARCH_STRNCPY=n
+CONFIG_ARCH_STRLEN=n
+CONFIG_ARCH_BZERO=n
+CONFIG_ARCH_KMALLOC=n
+CONFIG_ARCH_KZMALLOC=n
+CONFIG_ARCH_KFREE=n
+
+#
+# General build options
+#
+# CONFIG_RRLOAD_BINARY - make the rrload binary format used with
+#   BSPs from www.ridgerun.com
+#
+CONFIG_RRLOAD_BINARY=n
+
+#
+# Sizes of configurable things (0 disables)
+#
+# CONFIG_MAX_TASKS - The maximum number of simultaneously
+#   actived tasks.  This value must be a power of two.
+# CONFIG_MAX_TASK_ARGS - This controls the maximum number of
+#   of parameters that a task may receive (i.e., maxmum value
+#   of 'argc')
+# CONFIG_NPTHREAD_KEYS - The number of items of thread-
+#   specific data that can be retained
+# CONFIG_NFILE_DESCRIPTORS - The maximum number of file
+#   descriptors (one for each open)
+# CONFIG_NFILE_STREAMS - The maximum number of streams that
+#   can be fopen'ed
+# CONFIG_NAME_MAX - The maximum size of a file name.
+# CONFIG_STDIO_BUFFER_SIZE - Size of the buffer to allocate
+#   on fopen. (Only if CONFIG_NFILE_STREAMS > 0)
+# CONFIG_NUNGET_CHARS - Number of characters that can be
+#   buffered by ungetc() (Only if CONFIG_NFILE_STREAMS > 0)
+# CONFIG_PREALLOC_MQ_MSGS - The number of pre-allocated message
+#   structures.  The system manages a pool of preallocated
+#   message structures to minimize dynamic allocations
+# CONFIG_MQ_MAXMSGSIZE - Message structures are allocated with
+#   a fixed payload size given by this settin (does not include
+#   other message structure overhead.
+# CONFIG_MAX_WDOGPARMS - Maximum number of parameters that
+#   can be passed to a watchdog handler
+# CONFIG_PREALLOC_WDOGS - The number of pre-allocated watchdog
+#   structures.  The system manages a pool of preallocated
+#   watchdog structures to minimize dynamic allocations
+# CONFIG_PREALLOC_TIMERS - The number of pre-allocated POSIX
+#   timer structures.  The system manages a pool of preallocated
+#   timer structures to minimize dynamic allocations.  Set to
+#   zero for all dynamic allocations.
+#
+CONFIG_MAX_TASKS=8
+CONFIG_MAX_TASK_ARGS=4
+CONFIG_NPTHREAD_KEYS=0
+CONFIG_NFILE_DESCRIPTORS=0
+CONFIG_NFILE_STREAMS=0
+CONFIG_NAME_MAX=32
+CONFIG_STDIO_BUFFER_SIZE=0
+CONFIG_NUNGET_CHARS=0
+CONFIG_PREALLOC_MQ_MSGS=0
+CONFIG_MQ_MAXMSGSIZE=0
+CONFIG_MAX_WDOGPARMS=2
+CONFIG_PREALLOC_WDOGS=4
+CONFIG_PREALLOC_TIMERS=0
+
+#
+# TCP/IP and UDP support via uIP
+# CONFIG_NET - Enable or disable all network features
+# CONFIG_NET_IPv6 - Build in support for IPv6
+# CONFIG_NSOCKET_DESCRIPTORS - Maximum number of socket descriptors per task/thread.
+# CONFIG_NET_SOCKOPTS - Enable or disable support for socket options
+# CONFIG_NET_BUFSIZE - uIP buffer size
+# CONFIG_NET_TCP - TCP support on or off
+# CONFIG_NET_TCP_CONNS - Maximum number of TCP connections (all tasks)
+# CONFIG_NET_TCP_READAHEAD_BUFSIZE - Size of TCP read-ahead buffers
+# CONFIG_NET_NTCP_READAHEAD_BUFFERS - Number of TCP read-ahead buffers (may be zero)
+# CONFIG_NET_MAX_LISTENPORTS - Maximum number of listening TCP ports (all tasks)
+# CONFIG_NET_UDP - UDP support on or off
+# CONFIG_NET_UDP_CHECKSUMS - UDP checksums on or off
+# CONFIG_NET_UDP_CONNS - The maximum amount of concurrent UDP connections
+# CONFIG_NET_ICMP - ICMP ping support on or off
+# CONFIG_NET_PINGADDRCONF - Use "ping" packet for setting IP address
+# CONFIG_NET_STATISTICS - uIP statistics on or off
+# CONFIG_NET_RECEIVE_WINDOW - The size of the advertised receiver's window
+# CONFIG_NET_ARPTAB_SIZE - The size of the ARP table
+# CONFIG_NET_BROADCAST - Broadcast support
+# CONFIG_NET_LLH_LEN - The link level header length
+# CONFIG_NET_FWCACHE_SIZE - number of packets to remember when looking for duplicates
+CONFIG_NET=n
+CONFIG_NET_IPv6=n
+CONFIG_NSOCKET_DESCRIPTORS=0
+CONFIG_NET_SOCKOPTS=y
+CONFIG_NET_BUFSIZE=420
+CONFIG_NET_TCP=n
+CONFIG_NET_TCP_CONNS=40
+CONFIG_NET_MAX_LISTENPORTS=40
+CONFIG_NET_UDP=n
+CONFIG_NET_UDP_CHECKSUMS=y
+#CONFIG_NET_UDP_CONNS=10
+CONFIG_NET_ICMP=n
+#CONFIG_NET_PINGADDRCONF=0
+CONFIG_NET_STATISTICS=y
+#CONFIG_NET_RECEIVE_WINDOW=
+#CONFIG_NET_ARPTAB_SIZE=8
+CONFIG_NET_BROADCAST=n
+#CONFIG_NET_LLH_LEN=14
+#CONFIG_NET_FWCACHE_SIZE=2
+
+#
+# UIP Network Utilities
+# CONFIG_NET_DHCP_LIGHT - Reduces size of DHCP
+# CONFIG_NET_RESOLV_ENTRIES - Number of resolver entries
+CONFIG_NET_DHCP_LIGHT=n
+CONFIG_NET_RESOLV_ENTRIES=4
+
+#
+# Settings for examples/nsh
+CONFIG_EXAMPLES_NSH_TELNET=n
+CONFIG_EXAMPLES_NSH_IOBUFFER_SIZE=512
+CONFIG_EXAMPLES_NSH_CMD_SIZE=40
+CONFIG_EXAMPLES_NSH_STACKSIZE=4096
+CONFIG_EXAMPLES_NSH_DHCPC=n
+CONFIG_EXAMPLES_NSH_NOMAC=n
+CONFIG_EXAMPLES_NSH_IPADDR=(10<<24|0<<16|0<<8|2)
+CONFIG_EXAMPLES_NSH_DRIPADDR=(10<<24|0<<16|0<<8|1)
+CONFIG_EXAMPLES_NSH_NETMASK=(255<<24|255<<16|255<<8|0)
+
+#
+# Stack and heap information
+#
+# CONFIG_BOOT_FROM_FLASH - Some configurations support XIP
+#   operation from FLASH.
+# CONFIG_CUSTOM_STACK - The up_ implementation will handle
+#   all stack operations outside of the nuttx model.
+# CONFIG_STACK_POINTER - The initial stack pointer
+# CONFIG_PROC_STACK_SIZE - The size of the initial stack
+# CONFIG_PTHREAD_STACK_MIN - Minimum pthread stack size
+# CONFIG_PTHREAD_STACK_DEFAULT - Default pthread stack size
+# CONFIG_HEAP_BASE - The beginning of the heap
+# CONFIG_HEAP_SIZE - The size of the heap
+#
+CONFIG_BOOT_FROM_FLASH=n
+CONFIG_CUSTOM_STACK=n
+CONFIG_PROC_STACK_SIZE=1024
+CONFIG_PTHREAD_STACK_MIN=
+CONFIG_PTHREAD_STACK_DEFAULT=
+CONFIG_HEAP_SIZE=32768
+CONFIG_HEAP_BASE=CONFIG_DRAM_SIZE-CONFIG_HEAP_SIZE
diff --git a/nuttx/configs/z80sim/include/README.txt b/nuttx/configs/z80sim/include/README.txt
new file mode 100644
index 000000000..4af1b2ad2
--- /dev/null
+++ b/nuttx/configs/z80sim/include/README.txt
@@ -0,0 +1 @@
+This directory contains header files unique to the z80 simulation
diff --git a/nuttx/configs/z80sim/include/board.h b/nuttx/configs/z80sim/include/board.h
new file mode 100644
index 000000000..85edae22c
--- /dev/null
+++ b/nuttx/configs/z80sim/include/board.h
@@ -0,0 +1,51 @@
+/************************************************************
+ * board/board.h
+ *
+ *   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.
+ *
+ ************************************************************/
+
+#ifndef __ARCH_BOARD_BOARD_H
+#define __ARCH_BOARD_BOARD_H
+
+/************************************************************
+ * Included Files
+ ************************************************************/
+
+/************************************************************
+ * Definitions
+ ************************************************************/
+
+/************************************************************
+ * Inline Functions
+ ************************************************************/
+
+#endif  /* __ARCH_BOARD_BOARD_H */
diff --git a/nuttx/configs/z80sim/setenv.sh b/nuttx/configs/z80sim/setenv.sh
new file mode 100755
index 000000000..69614aefe
--- /dev/null
+++ b/nuttx/configs/z80sim/setenv.sh
@@ -0,0 +1,45 @@
+#!/bin/sh
+# setenv.sh
+#
+#   Copyright (C) 2007 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 Gregory Nutt 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.
+#
+
+if [ "$(basename $0)" = "setenv" ] ; then
+  echo "You must source this script, not run it!" 1>&2
+  exit 1
+fi
+
+if [ -z ${PATH_ORIG} ]; then export PATH_ORIG=${PATH}; fi
+
+export SDCC_BIN=/usr/local/bin
+export PATH=${SDCC_BIN}:/sbin:/usr/sbin:${PATH_ORIG}
+
+echo "PATH : ${PATH}"
diff --git a/nuttx/configs/z80sim/src/Makefile b/nuttx/configs/z80sim/src/Makefile
new file mode 100644
index 000000000..24226f2f9
--- /dev/null
+++ b/nuttx/configs/z80sim/src/Makefile
@@ -0,0 +1,79 @@
+############################################################
+# Makefile
+#
+#   Copyright (C) 2007 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 Gregory Nutt 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.
+#
+############################################################
+
+-include $(TOPDIR)/Make.defs
+
+MKDEP 		= $(TOPDIR)/tools/mkdeps.sh
+CFLAGS		+= -I$(TOPDIR)/sched
+
+ASRCS		= z80_lowputc$(ASMEXT) 
+AOBJS		= $(ASRCS:$(ASMEXT)=$(OBJEXT))
+CSRCS		= z80_decodeirq.c z80_irq.c z80_serial.c z80_timerisr.c
+COBJS		= $(CSRCS:.c=$(OBJEXT))
+
+SRCS		= $(ASRCS) $(CSRCS)
+OBJS		= $(AOBJS) $(COBJS)
+
+CFLAGS		+= -I $(TOPDIR)/arch/$(CONFIG_ARCH)/src
+
+all: libboard$(LIBEXT)
+
+$(AOBJS): %$(OBJEXT): %$(ASMEXT)
+	$(CC) -c $(CFLAGS) -D__ASSEMBLY__ $< -o $@
+
+$(COBJS) $(LINKOBJS): %$(OBJEXT): %.c
+	$(CC) -c $(CFLAGS) $< -o $@
+
+libboard$(LIBEXT): $(OBJS)
+	( for obj in $(OBJS) ; do \
+		$(AR) $@ $${obj} || \
+			{ echo "$(AR) $@ $obj FAILED!" ; exit 1 ; } ; \
+	done ; )
+
+.depend: Makefile $(SRCS)
+	$(MKDEP) $(CC) -- $(CFLAGS) -- $(SRCS) >Make.dep
+	touch $@
+
+depend: .depend
+
+clean:
+	rm -f libboard$(LIBEXT)
+	rm -f *.asm *.rel *.lst *.rst *.sym *.adb *.lnk *.map *.mem *.ihx *.hex *~
+	if [ ! -z "$(OBJEXT)" ]; then rm -f *$(OBJEXT); fi
+
+distclean: clean
+	rm -f Make.dep .depend
+
+-include Make.dep
diff --git a/nuttx/configs/z80sim/src/README.txt b/nuttx/configs/z80sim/src/README.txt
new file mode 100644
index 000000000..13c1e3e58
--- /dev/null
+++ b/nuttx/configs/z80sim/src/README.txt
@@ -0,0 +1 @@
+This directory contains drivers unique to the z80 simulation
diff --git a/nuttx/configs/z80sim/src/z80_decodeirq.c b/nuttx/configs/z80sim/src/z80_decodeirq.c
new file mode 100644
index 000000000..d4faf0f89
--- /dev/null
+++ b/nuttx/configs/z80sim/src/z80_decodeirq.c
@@ -0,0 +1,119 @@
+/********************************************************************************
+ * z80/z80_decodeirq.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 Funtions
+ ********************************************************************************/
+
+void up_decodeirq(uint16* 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. */
+
+  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);
+
+          /* 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;
+
+          /* Deliver the IRQ */
+
+          irq_dispatch(irq, regs);
+
+          /* Indicate that we are no long in an interrupt handler */
+
+          current_regs = NULL;
+
+          /* Unmask the last interrupt (global interrupts are still
+           * disabled.
+           */
+
+          up_enable_irq(irq);
+        }
+    }
+#endif
+}
diff --git a/nuttx/configs/z80sim/src/z80_irq.c b/nuttx/configs/z80sim/src/z80_irq.c
new file mode 100644
index 000000000..3c3443663
--- /dev/null
+++ b/nuttx/configs/z80sim/src/z80_irq.c
@@ -0,0 +1,110 @@
+/****************************************************************************
+ * z80/z80_irq.c
+ *
+ *   Copyright (C) 2007 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 Gregory Nutt 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 "up_arch.h"
+#include "os_internal.h"
+#include "up_internal.h"
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+uint32 *current_regs;
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Funtions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_irqinitialize
+ ****************************************************************************/
+
+void up_irqinitialize(void)
+{
+  /* currents_regs is non-NULL only while processing an interrupt */
+
+  current_regs = NULL;
+
+  /* And finally, enable interrupts */
+
+#ifndef CONFIG_SUPPRESS_INTERRUPTS
+  irqrestore(TRUE);
+#endif
+}
+
+/****************************************************************************
+ * Name: up_disable_irq
+ *
+ * Description:
+ *   Disable the IRQ specified by 'irq'
+ *
+ ****************************************************************************/
+
+void up_disable_irq(int irq)
+{
+  irqrestore(FALSE);
+}
+
+/****************************************************************************
+ * Name: up_enable_irq
+ *
+ * Description:
+ *   Enable the IRQ specified by 'irq'
+ *
+ ****************************************************************************/
+
+void up_enable_irq(int irq)
+{
+ irqrestore(TRUE);
+}
diff --git a/nuttx/configs/z80sim/src/z80_serial.c b/nuttx/configs/z80sim/src/z80_serial.c
new file mode 100644
index 000000000..73bba4932
--- /dev/null
+++ b/nuttx/configs/z80sim/src/z80_serial.c
@@ -0,0 +1,334 @@
+/****************************************************************************
+ * z80/z80_serial.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 <unistd.h>
+#include <semaphore.h>
+#include <string.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/irq.h>
+#include <nuttx/arch.h>
+#include <nuttx/serial.h>
+#include <arch/serial.h>
+
+#include "up_arch.h"
+#include "os_internal.h"
+#include "up_internal.h"
+
+#if CONFIG_NFILE_DESCRIPTORS > 0
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int     up_setup(struct uart_dev_s *dev);
+static void    up_shutdown(struct uart_dev_s *dev);
+static int     up_interrupt(int irq, void *context);
+static int     up_ioctl(struct file *filep, int cmd, unsigned long arg);
+static int     up_receive(struct uart_dev_s *dev, uint32 *status);
+static void    up_rxint(struct uart_dev_s *dev, boolean enable);
+static boolean up_rxfifonotempty(struct uart_dev_s *dev);
+static void    up_send(struct uart_dev_s *dev, int ch);
+static void    up_txint(struct uart_dev_s *dev, boolean enable);
+static boolean up_txfifonotfull(struct uart_dev_s *dev);
+static boolean up_txfifoempty(struct uart_dev_s *dev);
+
+/****************************************************************************
+ * Private Variables
+ ****************************************************************************/
+
+struct uart_ops_s g_uart_ops =
+{
+  .setup          = up_setup,
+  .shutdown       = up_shutdown,
+  .handler        = up_interrupt,
+  .ioctl          = up_ioctl,
+  .receive        = up_receive,
+  .rxint          = up_rxint,
+  .rxfifonotempty = up_rxfifonotempty,
+  .send           = up_send,
+  .txint          = up_txint,
+  .txfifonotfull  = up_txfifonotfull,
+  .txfifoempty    = up_txfifoempty,
+};
+
+/* I/O buffers */
+
+static char g_uartrxbuffer[CONFIG_UART0_RXBUFSIZE];
+static char g_uarttxbuffer[CONFIG_UART0_TXBUFSIZE];
+
+/* This describes the state of the fake UART port. */
+
+static uart_dev_t g_uartport =
+{
+  .irq      = DM320_IRQ_UART0,
+  .recv     =
+  {
+    .size   = CONFIG_UART0_RXBUFSIZE,
+    .buffer = g_uart0rxbuffer,
+  },
+  .xmit     =
+  {
+    .size   = CONFIG_UART0_TXBUFSIZE,
+    .buffer = g_uart0txbuffer,
+  },
+  .ops      = &g_uart_ops,
+  .priv     = NULL,
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_setup
+ *
+ * Description:
+ *   Configure the UART baud, bits, parity, fifos, etc. This
+ *   method is called the first time that the serial port is
+ *   opened.
+ *
+ ****************************************************************************/
+
+static int up_setup(struct uart_dev_s *dev)
+{
+  return OK;
+}
+
+/****************************************************************************
+ * Name: up_shutdown
+ *
+ * Description:
+ *   Disable the UART.  This method is called when the serial
+ *   port is closed
+ *
+ ****************************************************************************/
+
+static void up_shutdown(struct uart_dev_s *dev)
+{
+}
+
+/****************************************************************************
+ * Name: up_interrupt
+ *
+ * Description:
+ *   This is the UART interrupt handler.  It will be invoked
+ *   when an interrupt received on the 'irq'  It should call
+ *   uart_transmitchars or uart_receivechar to perform the
+ *   appropriate data transfers.  The interrupt handling logic\
+ *   must be able to map the 'irq' number into the approprite
+ *   uart_dev_s structure in order to call these functions.
+ *
+ ****************************************************************************/
+
+static int up_interrupt(int irq, void *context)
+{
+  return OK;
+}
+
+/****************************************************************************
+ * Name: up_ioctl
+ *
+ * Description:
+ *   All ioctl calls will be routed through this method
+ *
+ ****************************************************************************/
+
+static int up_ioctl(struct file *filep, int cmd, unsigned long arg)
+{
+  *get_errno_ptr() = ENOTTY;
+  return ERROR;
+}
+
+/****************************************************************************
+ * Name: up_receive
+ *
+ * Description:
+ *   Called (usually) from the interrupt level to receive one
+ *   character from the UART.  Error bits associated with the
+ *   receipt are provided in the the return 'status'.
+ *
+ ****************************************************************************/
+
+static int up_receive(struct uart_dev_s *dev, uint32 *status)
+{
+  uint8 ch = up_lowgetc();
+  *status = 0;
+  return ch;
+}
+
+/****************************************************************************
+ * Name: up_rxint
+ *
+ * Description:
+ *   Call to enable or disable RX interrupts
+ *
+ ****************************************************************************/
+
+static void up_rxint(struct uart_dev_s *dev, boolean enable)
+{
+}
+
+/****************************************************************************
+ * Name: up_rxfifonotempty
+ *
+ * Description:
+ *   Return TRUE if the receive fifo is not empty
+ *
+ ****************************************************************************/
+
+static boolean up_rxfifonotempty(struct uart_dev_s *dev)
+{
+  return TRUE;
+}
+
+/****************************************************************************
+ * Name: up_send
+ *
+ * Description:
+ *   This method will send one byte on the UART
+ *
+ ****************************************************************************/
+
+static void up_send(struct uart_dev_s *dev, int ch)
+{
+  up_lowputc(ch);
+}
+
+/****************************************************************************
+ * Name: up_txint
+ *
+ * Description:
+ *   Call to enable or disable TX interrupts
+ *
+ ****************************************************************************/
+
+static void up_txint(struct uart_dev_s *dev, boolean enable)
+{
+}
+
+/****************************************************************************
+ * Name: up_txfifonotfull
+ *
+ * Description:
+ *   Return TRUE if the tranmsit fifo is not full
+ *
+ ****************************************************************************/
+
+static boolean up_txfifonotfull(struct uart_dev_s *dev)
+{
+  return TRUE;
+}
+
+/****************************************************************************
+ * Name: up_txfifoempty
+ *
+ * Description:
+ *   Return TRUE if the transmit fifo is empty
+ *
+ ****************************************************************************/
+
+static boolean up_txfifoempty(struct uart_dev_s *dev)
+{
+  return FALSE;
+}
+
+/****************************************************************************
+ * Public Funtions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_serialinit
+ *
+ * Description:
+ *   Performs the low level UART initialization early in 
+ *   debug so that the serial console will be available
+ *   during bootup.  This must be called before up_serialinit.
+ *
+ ****************************************************************************/
+
+void up_earlyserialinit(void)
+{
+}
+
+/****************************************************************************
+ * Name: up_serialinit
+ *
+ * Description:
+ *   Register serial console and serial ports.  This assumes
+ *   that up_earlyserialinit was called previously.
+ *
+ ****************************************************************************/
+
+void up_serialinit(void)
+{
+  (void)uart_register("/dev/console", &g_uartport);
+  (void)uart_register("/dev/ttyS0", &g_uartport);
+}
+#endif /* CONFIG_NFILE_DESCRIPTORS > 0 */
+
+/****************************************************************************
+ * Name: up_putc
+ *
+ * Description:
+ *   Provide priority, low-level access to support OS debug
+ *   writes
+ *
+ ****************************************************************************/
+
+int up_putc(int ch)
+{
+  up_lowputc(ch);
+}
+
+
+
+
diff --git a/nuttx/configs/z80sim/src/z80_timerisr.c b/nuttx/configs/z80sim/src/z80_timerisr.c
new file mode 100644
index 000000000..603a66c91
--- /dev/null
+++ b/nuttx/configs/z80sim/src/z80_timerisr.c
@@ -0,0 +1,153 @@
+/************************************************************
+ * dm320/dm320_timerisr.c
+ *
+ *   Copyright (C) 2007 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 Gregory Nutt 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 <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.
+ *
+ ************************************************************/
+
+int up_timerisr(int irq, uint32 *regs)
+{
+   /* Process timer interrupt */
+
+   sched_process_timer();
+   return 0;
+}
+
+/************************************************************
+ * Function:  up_timerinit
+ *
+ * Description:
+ *   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);
+}
+