The Amber processor core is an ARM-compatible 32-bit RISC processor. The Amber core is fully compatible with the ARM® v2a instruction set architecture (ISA) and is therefore supported by the GNU toolset.
I would like to try run on my Mac Mini, so, I install Armber, tools and do some modification…

1. Download the Amber project from the Opencores Subversion server

$ mkdir ~/AmberInstallPath
$ cd ~/AmberInstallPath
$ svn --username YOUR_NAME -password PASSWORD co http://opencores.org/ocsvn/amber/amber/trunk

2. Install the GNU cross compiler

$ sudo port install arm-none-linux-gnueabi-gcc
$ sudo port install gawk
$ cd /opt/local/bin
$ sudo ln -s gawk awk
$ sudo ln -s arm-none-linux-gnueabi-gcc-2005q3 arm-none-linux-gnueabi-gcc

3. Install Icarus Verilog Simulator

$ sudo port install iverilog

4. Edit ~/.profile and add the following

$ export AMBER_BASE=~/AmberInstallPath/trunk
$ export AMBER_CROSSTOOL=arm-none-linux-gnueabi

5. Make scripts executable and create a run link

$ cd $AMBER_BASE
$ chmod +x hw/tools/*.sh sw/tools/*.sh
$ ln -s ../tools/run.sh hw/sim/run

6. Create $AMBER_BASE/hw/tools/runIV.patch by following

--- run.sh	2011-04-29 08:47:23.000000000 +0800
+++ runIV.sh	2011-04-29 09:14:21.000000000 +0800
@@ -46,12 +46,9 @@
 AMBER_LOAD_MAIN_MEM=" "
 AMBER_TIMEOUT=0
 AMBER_LOG_FILE="tests.log"
-SET_G=0
 SET_M=0
 SET_D=0
 SET_T=0
-SET_S=0
-SET_V=0
 SET_A=0
 SET_5=0

@@ -59,14 +56,11 @@ SET_5=0
 # show program usage
 show_usage() {
     echo "Usage:"
-    echo "run  [-a] [-g] [-d] [-t] [-s] [-v]"
+    echo "run  [-a] [-d] [-t]"
     echo " -h : Help"
     echo " -a : Run hardware tests (all tests in $AMBER_BASE/hw/tests)"
-    echo " -g : Use Modelsim GUI"
     echo " -d : Create vcd file"
     echo " -t : Create vcd file and terminate"
-    echo " -s : Use Xilinx Spatran6 Libraries (slower sim)"
-    echo " -v : Use Xilinx Virtex6 Libraries (slower sim)"
     echo " -5 : Use Amber25 core instead of Amber23 core"
     echo ""
     exit
@@ -103,14 +97,8 @@ do
             case $1 in
                 -a)     SET_A=1   # all tests
                         shift ;;
-                -s)     SET_S=1   # Xilinx libs
-                        shift ;;
-                -v)     SET_V=1   # Xilinx libs
-                        shift ;;
                 -5)     SET_5=1   # Xilinx libs
                         shift ;;
-                -g)     SET_G=1   # Bring up GUI
-                        shift ;;
                 -d)     SET_D=1
                         DUMP_START=$2
                         shift 2;;
@@ -135,24 +123,7 @@ done
 # Set comfiguration based on command-line options
 #--------------------------------------------------------

-if [ $SET_G == 1 ]; then
-    RUN_OPTIONS="-do cmd.do"
-else    
-    RUN_OPTIONS="${RUN_OPTIONS} -c -do run.do"
-fi
-
-if [ $SET_S == 1 ]; then
-    FPGA="+define+XILINX_SPARTAN6_FPGA +define+XILINX_FPGA"
-    RUN_OPTIONS="${RUN_OPTIONS} -t ps  +notimingchecks -L unisims_ver -L secureip"
-else    
-    if [ $SET_V == 1 ]; then
-        FPGA="+define+XILINX_VIRTEX6_FPGA +define+XILINX_FPGA"
-        RUN_OPTIONS="${RUN_OPTIONS} -t ps  +notimingchecks"
-    else    
-        FPGA=" "
-    fi
-fi
-
+RUN_OPTIONS="-f iverilog.f"

 if [ $SET_D == 1 ]; then
     AMBER_DUMP_VCD="+define+AMBER_DUMP_VCD +define+AMBER_DUMP_START=$DUMP_START"
@@ -173,13 +144,8 @@ else    
 fi

 if [ $SET_A == 1 ]; then
-    if [ $SET_S == 1 ]; then
-        TECH="-s"
-    elif [ $SET_V == 1 ]; then
-        TECH="-v"
-    else    
-        TECH=" "
-    fi        
+
+    TECH=" "

     if [ $SET_5 == 1 ]; then
         CORE="-5"
@@ -273,54 +239,42 @@ fi

 #--------------------------------------------------------
-# Modelsim
+# iVerilog
 #--------------------------------------------------------
-if [ $MAKE_STATUS == 0 ]; then
-   if [ ! -d work ]; then
-       vlib work
-   fi
-
-   if [ $? == 0 ]; then
-       vlog +libext+.v 
-            +incdir+../vlog/amber23+../vlog/amber25+../vlog/system+../vlog/tb+../vlog/ethmac 
-            +incdir+../vlog/lib+../vlog/xs6_ddr3+../vlog/xv6_ddr3 
-            -y ../vlog/amber23 -y ../vlog/amber25 -y ../vlog/system  -y ../vlog/tb -y ../vlog/ethmac 
-            -y ../vlog/lib   -y ../vlog/xs6_ddr3 -y ../vlog/xv6_ddr3  
-            -y $XILINX/verilog/src/unisims 
-            -y $XILINX/verilog/src 
-            ../vlog/tb/tb.v 
-            $XILINX/verilog/src/glbl.v 
-            +define+BOOT_MEM_FILE="$BOOT_MEM_FILE" 
-            +define+BOOT_MEM_PARAMS_FILE="$BOOT_MEM_PARAMS_FILE" 
-            +define+MAIN_MEM_FILE="$MAIN_MEM_FILE" 
-            +define+AMBER_LOG_FILE="$AMBER_LOG_FILE" 
-            +define+AMBER_TEST_NAME="$AMBER_TEST_NAME" 
-            +define+AMBER_SIM_CTRL=$TEST_TYPE 
-            +define+AMBER_TIMEOUT=$AMBER_TIMEOUT 
-            ${FPGA} 
-            $AMBER_CORE 
-            $AMBER_DUMP_VCD 
-            $AMBER_TERMINATE 
-            $AMBER_LOAD_MAIN_MEM
-                  
-        if [ $? == 0 ]; then
-            vsim -voptargs="+acc=rnpc" tb ${RUN_OPTIONS}
-            
-            # Set a timeout value for the test if it passed
-            if [ $TEST_TYPE == 1 ]; then
-                tail -1  /dev/null
-                if  [ $? == 0 ]; then
-                    TICKS=`tail -1 > $AMBER_LOG_FILE
-fi
+      echo "+libext+.v"                > iverilog.f
+      echo "+incdir+../vlog/amber23"  >> iverilog.f
+      echo "+incdir+../vlog/amber25"  >> iverilog.f
+      echo "+incdir+../vlog/system"   >> iverilog.f
+      echo "+incdir+../vlog/tb"       >> iverilog.f
+      echo "+incdir+../vlog/ethmac"   >> iverilog.f
+      echo "+incdir+../vlog/lib"      >> iverilog.f
+      echo "+incdir+../vlog/xs6_ddr3" >> iverilog.f
+      echo "+incdir+../vlog/xv6_ddr3" >> iverilog.f
+      echo "-y../vlog/amber23"        >> iverilog.f
+      echo "-y../vlog/amber25"        >> iverilog.f
+      echo "-y../vlog/system"         >> iverilog.f
+      echo "-y../vlog/tb"             >> iverilog.f
+      echo "-y../vlog/ethmac"         >> iverilog.f
+      echo "-y../vlog/lib"            >> iverilog.f
+      echo "-y../vlog/xs6_ddr3"       >> iverilog.f
+      echo "-y../vlog/xv6_ddr"        >> iverilog.f
+      echo "+define+BOOT_MEM_FILE="$BOOT_MEM_FILE""               >> iverilog.f
+      echo "+define+BOOT_MEM_PARAMS_FILE="$BOOT_MEM_PARAMS_FILE"" >> iverilog.f
+      echo "+define+MAIN_MEM_FILE="$MAIN_MEM_FILE""               >> iverilog.f
+      echo "+define+AMBER_LOG_FILE="$AMBER_LOG_FILE""             >> iverilog.f
+      echo "+define+AMBER_TEST_NAME="$AMBER_TEST_NAME""           >> iverilog.f
+      echo "+define+AMBER_SIM_CTRL=$TEST_TYPE"                      >> iverilog.f
+      echo "+define+AMBER_TIMEOUT=$AMBER_TIMEOUT"                   >> iverilog.f
+      echo "$AMBER_CORE"          >> iverilog.f
+      echo "$AMBER_DUMP_VCD"      >> iverilog.f
+      echo "$AMBER_TERMINATE"     >> iverilog.f
+      echo "$AMBER_LOAD_MAIN_MEM" >> iverilog.f
+      echo "../vlog/tb/tb.v"      >> iverilog.f
+
+      rm -rf ./armber
+      iverilog -f iverilog.f -o armber
+      ./armber

7. Create runIV script for iverilog simulator

$ cd $AMBER_BASE/hw/tools
$ patch -o runIV.sh -i runIV.patch
$ chmod +x runIV.sh
$ cd $AMBER_BASE/hw/sim
$ ln -s ../tools/runIV.sh runIV

8. If you see the iverilog compile error message for log2 function in next step, you could replace log2 by $clog2 to solve the problem.

9. Run a Hello-World Test with Amber 25

$ cd $AMBER_BASE/hw/sim
$ runIV -5 hello-world

10. Hello-World simulation Result

Amber Boot Loader v20110202130047
Hello, World!

----------------------------------------------------------------------------
Amber Core
       > User         FIRQ         IRQ          SVC
r0       0x00000010
r1       0x16000000
r2       0x00000000
r3       0x00000000
r4       0x0c80e403
r5       0x00000000
r6       0x00000000
r7       0x00000000
r8       0xdeadbeef   0xdeadbeef 
r9       0xdeadbeef   0xdeadbeef 
r10      0x00000011   0xdeadbeef 
r11      0xf0000000   0xdeadbeef 
r12      0x00000000   0xdeadbeef 
r13      0x08000000   0xdeadbeef   0xdeadbeef   0x01ffffb8
r14 (lr) 0x0080e420   0xdeadbeef   0xdeadbeef   0x20000787
r15 (pc) 0x0080e960

Status Bits: N=0, Z=1, C=1, V=0, IRQ Mask 0, FIRQ Mask 0, Mode = User          
----------------------------------------------------------------------------

++++++++++++++++++++
Passed hello-world 29320 ticks
++++++++++++++++++++