[SeaBIOS] [PATCH] build: allow setting tools path from the environment

[Roger Pau Monne]

Allow setting the path to as, ld, objcopy, objdump, strip and python
from the environment.

This is required for building SeaBIOS on FreeBSD, which will switch
the default ld to lld very soon, and lld is not capable of building
SeaBIOS at the moment.

Building SeaBIOS on FreeBSD after the switch to lld will require
setting LD=/path/to/gnu/ld at build time.

Signed-off-by: Roger Pau Monné 
---
Cc: Kevin O'Connor 
Cc: Ed Maste 
---
 Makefile | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/Makefile b/Makefile
index eb8ad58..0fcb1bf 100644
--- a/Makefile
+++ b/Makefile
@@ -17,12 +17,12 @@ CROSS_PREFIX=
 ifneq ($(CROSS_PREFIX),)
 CC=$(CROSS_PREFIX)gcc
 endif
-AS=$(CROSS_PREFIX)as
-LD=$(CROSS_PREFIX)ld
-OBJCOPY=$(CROSS_PREFIX)objcopy
-OBJDUMP=$(CROSS_PREFIX)objdump
-STRIP=$(CROSS_PREFIX)strip
-PYTHON=python
+AS?=$(CROSS_PREFIX)as
+LD?=$(CROSS_PREFIX)ld
+OBJCOPY?=$(CROSS_PREFIX)objcopy
+OBJDUMP?=$(CROSS_PREFIX)objdump
+STRIP?=$(CROSS_PREFIX)strip
+PYTHON?=python
 CPP=cpp
 IASL:=iasl
 LD32BIT_FLAG:=-melf_i386