Stefan Fiedler:

package/base/linux/linux.conf

@@ -430,13 +430,18 @@ main_lx() {
 		;;
 	    mips)
 		eval $MAKE vmlinux
-		$BUILDCC arch/mips/boot/elf2ecoff.c -o elf2ecoff
-		./elf2ecoff vmlinux vmlinux.ecoff
+		# elf2ecoff only works for kernels with a 32-bit code model
+		if grep -q "^CONFIG_32BIT=y" .config ; then
+			$BUILDCC arch/mips/boot/elf2ecoff.c -o elf2ecoff
+			./elf2ecoff vmlinux vmlinux.ecoff
+		fi
 		cp -vf vmlinux $root/boot/vmlinux_${lx_kernelrelease}
-		cp -vf vmlinux.ecoff $root/boot/vmlinux_${lx_kernelrelease}.ecoff
+		[ -f vmlinux.ecoff ] && cp -vf vmlinux.ecoff \
+			$root/boot/vmlinux_${lx_kernelrelease}.ecoff
 		if [ "$xpkg" = "$ROCKCFG_PKG_LINUX_DEFAULT" ]; then
 			ln -svf vmlinux_${lx_kernelrelease} $root/boot/vmlinux
-			ln -svf vmlinux_${lx_kernelrelease}.ecoff $root/boot/vmlinux.ecoff
+			[ -f $root/boot/vmlinux.ecoff ] && ln -svf \
+				vmlinux_${lx_kernelrelease}.ecoff $root/boot/vmlinux.ecoff
 		fi
 		;;
 	    ppc)