From bc5f7cfb0aad52af4388f5b4cc6214baf1e1a8ed Mon Sep 17 00:00:00 2001
From: John Bachan <jbachan@nvidia.com>
Date: Thu, 7 Jul 2022 11:42:21 +0200
Subject: [PATCH] Changed top-level Makefile behavior so that BUILDDIR is
 interpreted as relative to top-level directory. This done is by abspath'ing
 it before passing it to subdirectory Makefile's.

The old behavior had two cases: with and without BUILDDIR being set by
the user. With BUILDDIR not set, the build dir would be named "build"
in the top-level directory. If BUILDDIR was set, then the build dir
would be placed at "src/${BUILDDIR}".

The new behavior is simpler, if BUILDDIR is not set then it defaults
to "build", and the directory holding the final build is always at just
"${BUILDDIR}" in the top level.
---
 Makefile | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 29409a8422..43729f897a 100644
--- a/Makefile
+++ b/Makefile
@@ -4,6 +4,9 @@
 # See LICENCE.txt for license information
 #
 
+BUILDDIR ?= build
+override BUILDDIR := $(abspath $(BUILDDIR))
+
 .PHONY : all clean
 
 default : src.build
@@ -14,7 +17,7 @@ all:   ${TARGETS:%=%.build}
 clean: ${TARGETS:%=%.clean}
 
 %.build:
-	${MAKE} -C $* build
+	${MAKE} -C $* build BUILDDIR=${BUILDDIR}
 
 %.clean:
-	${MAKE} -C $* clean
+	${MAKE} -C $* clean BUILDDIR=${BUILDDIR}