diff --git a/README.md b/README.md
index 379b76c..d2ec1cb 100644
--- a/README.md
+++ b/README.md
@@ -520,6 +520,10 @@ CPU.
 The following commands will build the RISC-V gnu toolchain and libraries for a
 pure RV32I target, and install it in `/opt/riscv32i`:
 
+    # Ubuntu packages needed:
+    sudo apt-get install autoconf automake autotools-dev curl libmpc-dev libmpfr-dev \
+            libgmp-dev gawk build-essential bison flex texinfo gperf
+
     sudo mkdir /opt/riscv32i
     sudo chown $USER /opt/riscv32i
 
diff --git a/scripts/icestorm/Makefile b/scripts/icestorm/Makefile
index be7c4f7..8f70913 100644
--- a/scripts/icestorm/Makefile
+++ b/scripts/icestorm/Makefile
@@ -1,5 +1,5 @@
 
-TOOLCHAIN_PREFIX = riscv64-unknown-elf-
+TOOLCHAIN_PREFIX = riscv32-unknown-elf-
 
 all: example.bin
 
diff --git a/scripts/icestorm/example.pcf b/scripts/icestorm/example.pcf
index 8190282..a5c7398 100644
--- a/scripts/icestorm/example.pcf
+++ b/scripts/icestorm/example.pcf
@@ -1,3 +1,4 @@
+set_io clk J3
 set_io LED0 B5
 set_io LED1 B4
 set_io LED2 A2
@@ -6,9 +7,3 @@ set_io LED4 C5
 set_io LED5 C4
 set_io LED6 B3
 set_io LED7 C3
-
-# on-board oscillator (12.0 MHz)
-set_io clk_pin J3
-
-# external clock on PIO1_01 (pin 4 on 40 pin header)
-#set_io clk_pin R15
diff --git a/scripts/icestorm/example.v b/scripts/icestorm/example.v
index cd52c76..e1c64b4 100644
--- a/scripts/icestorm/example.v
+++ b/scripts/icestorm/example.v
@@ -1,15 +1,9 @@
 `timescale 1 ns / 1 ps
 
 module top (
-	input clk_pin,
+	input clk,
 	output reg LED0, LED1, LED2, LED3, LED4, LED5, LED6, LED7
 );
-	// -------------------------------
-	// Clock Buffer
-
-	wire clk = clk_pin;
-
-
 	// -------------------------------
 	// Reset Generator