From 345ffbb1f6106020daf4a4ea1381f7fa254e71aa Mon Sep 17 00:00:00 2001
From: Nathan Pemberton <nathanp@berkeley.edu>
Date: Mon, 3 May 2021 14:42:11 -0400
Subject: [PATCH] Require an environment variable for the linux source.
 FireMarshal already sets this variable and the default is not useful if you
 aren't using marshal anyway. This makes the requirement more clear.

---
 Makefile | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 340c359..4575046 100644
--- a/Makefile
+++ b/Makefile
@@ -4,8 +4,9 @@ obj-m += iceblk.o
 
 else
 
-# The default assumes you cloned this as part of firesim-software (FireMarshal)
-LINUXSRC=../../../../riscv-linux
+ifndef LINUXSRC
+$(error Please set the LINUXSRC environment variable to the path of your Linux source)
+endif
 
 KMAKE=make -C $(LINUXSRC) ARCH=riscv CROSS_COMPILE=riscv64-unknown-linux-gnu- M=$(PWD)