Add simple multiboot example for ECP5-EVN Signed-off-by: Jens Andersen <jens.andersen@gmail.com>

diff --git a/examples/ecp5_evn_multiboot/Makefile b/examples/ecp5_evn_multiboot/Makefile
new file mode 100644
index 0000000..948aad5
--- /dev/null
+++ b/examples/ecp5_evn_multiboot/Makefile

@@ -0,0 +1,23 @@
+all: multiboot.mcs
+
+%.json: %.v
+	yosys -p "synth_ecp5 -json $@" $<
+
+%_out.config: %.json
+	nextpnr-ecp5 --json $< --textcfg $@ --um5g-85k --package CABGA381 --lpf ecp5evn.lpf
+
+%.bit: %_out.config
+	ecppack $< $@
+
+
+multiboot.bin: blinky1.bit blinky2.bit
+	ecpmulti --flashsize 128 --input blinky1.bit --input blinky2.bit --address 0x00250000 $@
+
+multiboot.mcs: multiboot.bin
+	srec_cat $< -Binary -unfill 0xFF -Bit_Reverse=2 -Byte-Swap -o $@ -Intel
+
+clean:
+	rm -f *.svf *.bit *.config *.json multiboot.bin multiboot.mcs
+
+.PHONY: prog clean
+.PRECIOUS: blinky1.json blinky1_out.config blinky1.bit blinky2.json blinky2_out.config blinky2.bit multiboot.bin multiboot.mcs

diff --git a/examples/ecp5_evn_multiboot/README.md b/examples/ecp5_evn_multiboot/README.md
new file mode 100644
index 0000000..2f78a3a
--- /dev/null
+++ b/examples/ecp5_evn_multiboot/README.md

@@ -0,0 +1,18 @@
+# Purpose
+This example contains two separate verilog implementations
+1) Blinks LED 0 on EVN board
+2) Blinks LED 7 on EVN board
+
+It generates a multiboot.bin file as well as a suitable multiboot.mcs file.
+Once flashed, pressing PROGRAMN button will switch between the available
+bitstreams.
+
+# Usage
+In order to use, it must be flashed to the ECP5-EVN board.
+This can be done with the official programmer from lattice.
+The generated MCS (Intel Hex) file is sufficiently compatible with Lattice to
+allow flashing.
+However, flashing the bin/hex any other way should also work.
+Due to padding with SPI Flash erase byte, it will be significantly faster to
+flash the hex file.
+

diff --git a/examples/ecp5_evn_multiboot/blinky1.v b/examples/ecp5_evn_multiboot/blinky1.v
new file mode 100644
index 0000000..f4fac91
--- /dev/null
+++ b/examples/ecp5_evn_multiboot/blinky1.v

@@ -0,0 +1,9 @@
+module top(input clk, input btn, output [7:0] led);
+    reg [23:0] cnt = 0;
+
+    always@(posedge clk) begin
+        cnt <= cnt + 1;
+    end
+    assign led[0] = cnt[22];
+    assign led[7:1] = 7'b1111111;
+endmodule

diff --git a/examples/ecp5_evn_multiboot/blinky2.v b/examples/ecp5_evn_multiboot/blinky2.v
new file mode 100644
index 0000000..d2fc694
--- /dev/null
+++ b/examples/ecp5_evn_multiboot/blinky2.v

@@ -0,0 +1,9 @@
+module top(input clk, input btn, output [7:0] led);
+    reg [23:0] cnt = 0;
+
+    always@(posedge clk) begin
+        cnt <= cnt + 1;
+    end
+    assign led[7] = cnt[22];
+    assign led[6:0] = 7'b1111111;
+endmodule

diff --git a/examples/ecp5_evn_multiboot/ecp5evn.lpf b/examples/ecp5_evn_multiboot/ecp5evn.lpf
new file mode 100644
index 0000000..bd32c6d
--- /dev/null
+++ b/examples/ecp5_evn_multiboot/ecp5evn.lpf

@@ -0,0 +1,23 @@
+LOCATE COMP "clk" SITE "A10";
+IOBUF PORT "clk" IO_TYPE=LVCMOS33;
+
+LOCATE COMP "btn" SITE "P4";
+IOBUF PORT "btn" IO_TYPE=LVCMOS33;
+
+LOCATE COMP "led[0]" SITE "A13";
+LOCATE COMP "led[1]" SITE "A12";
+LOCATE COMP "led[2]" SITE "B19";
+LOCATE COMP "led[3]" SITE "A18";
+LOCATE COMP "led[4]" SITE "B18";
+LOCATE COMP "led[5]" SITE "C17";
+LOCATE COMP "led[6]" SITE "A17";
+LOCATE COMP "led[7]" SITE "B17";
+
+IOBUF PORT "led[0]" IO_TYPE=LVCMOS33;
+IOBUF PORT "led[1]" IO_TYPE=LVCMOS33;
+IOBUF PORT "led[2]" IO_TYPE=LVCMOS33;
+IOBUF PORT "led[3]" IO_TYPE=LVCMOS33;
+IOBUF PORT "led[4]" IO_TYPE=LVCMOS33;
+IOBUF PORT "led[5]" IO_TYPE=LVCMOS33;
+IOBUF PORT "led[6]" IO_TYPE=LVCMOS33;
+IOBUF PORT "led[7]" IO_TYPE=LVCMOS33;