Backport prefix changes from aarch64

mk/config.mk

@@ -1,23 +1,20 @@
 # Configuration
 ARCH?=x86_64
 INSTALLER_FLAGS?=--cookbook=cookbook
+PREFIX_RUSTC?=0
 
 # Per host variables
 UNAME := $(shell uname)
 ifeq ($(UNAME),Darwin)
 	ECHO=/bin/echo
 	FUMOUNT=sudo umount
-	export LD=$(ARCH)-elf-ld
 	export NPROC=sysctl -n hw.ncpu
-	export STRIP=$(ARCH)-elf-strip
 	VB_AUDIO=coreaudio
 	VBM="/Applications/VirtualBox.app/Contents/MacOS/VBoxManage"
 else
 	ECHO=echo
 	FUMOUNT=fusermount -u
-	export LD=ld
 	export NPROC=nproc
-	export STRIP=strip
 	VB_AUDIO="pulse"
 	VBM=VBoxManage
 endif
@@ -28,6 +25,24 @@ export RUST_TARGET_PATH=$(ROOT)/kernel/targets
 export XARGO_HOME=$(ROOT)/build/xargo
 export XARGO_RUST_SRC=$(ROOT)/rust/src
 
+# Cross compiler variables
+AR=$(TARGET)-ar
+AS=$(TARGET)-as
+CC=$(TARGET)-gcc
+CXX=$(TARGET)-g++
+LD=$(TARGET)-ld
+NM=$(TARGET)-nm
+OBJCOPY=$(TARGET)-objcopy
+OBJDUMP=$(TARGET)-objdump
+RANLIB=$(TARGET)-ranlib
+READELF=$(TARGET)-readelf
+STRIP=$(TARGET)-strip
+
+# Rust cross compile variables
+export AR_$(subst -,_,$(TARGET))=$(TARGET)-ar
+export CC_$(subst -,_,$(TARGET))=$(TARGET)-gcc
+export CXX_$(subst -,_,$(TARGET))=$(TARGET)-g++
+
 # Kernel variables
 KTARGET=$(ARCH)-unknown-none
 KBUILD=build/kernel