test: enable running infix tests from external projects

Minor adjustments have been made to enable calling infix tests from an
external project (i.e. 'make test' target).
This essentially allows running any external test (or a group of tests)
using the infix-9pm tool.

test/test.mk

@@ -1,28 +1,35 @@
+base-dir := $(lastword $(subst :, ,$(BR2_EXTERNAL)))
 test-dir := $(BR2_EXTERNAL_INFIX_PATH)/test
 ninepm   := $(BR2_EXTERNAL_INFIX_PATH)/test/9pm/9pm.py
 
 UNIT_TESTS  ?= $(test-dir)/case/all-repo.yaml $(test-dir)/case/all-unit.yaml
-INFIX_TESTS ?= $(test-dir)/case/all.yaml
+TESTS ?= $(test-dir)/case/all.yaml
+
+IMAGE ?= infix
+TOPOLOGY-DIR ?= $(test-dir)/virt/quad
+
+base := -b $(base-dir)
 
 TEST_MODE ?= qeneth
-mode-qeneth := -q $(test-dir)/virt/quad
+mode-qeneth := -q $(TOPOLOGY-DIR)
 mode-host   := -t $(or $(TOPOLOGY),/etc/infamy.dot)
 mode-run    := -t $(BINARIES_DIR)/qemu.dot
 mode        := $(mode-$(TEST_MODE))
 
-binaries-$(ARCH) := $(addprefix infix-$(ARCH),.img -disk.img .pkg)
+
+binaries-$(ARCH) := $(addprefix $(IMAGE)-$(ARCH),.img -disk.img .pkg)
 binaries-x86_64  += OVMF.fd
 binaries := $(foreach bin,$(binaries-$(ARCH)),-f $(BINARIES_DIR)/$(bin))
 
 test:
-	$(test-dir)/env -r $(mode) $(binaries) $(ninepm) $(INFIX_TESTS)
+	$(test-dir)/env -r $(base) $(mode) $(binaries) $(ninepm) $(TESTS)
 
 test-sh:
-	$(test-dir)/env $(mode) $(binaries) -i /bin/sh
+	$(test-dir)/env $(base) $(mode) $(binaries) -i /bin/sh
 
 # Unit tests run with random (-r) hostname and container name to
 # prevent race conditions when running in CI environments.
 test-unit:
-	$(test-dir)/env -r $(ninepm) $(UNIT_TESTS)
+	$(test-dir)/env -r $(base) $(ninepm) $(UNIT_TESTS)
 
 .PHONY: test test-sh test-unit