sw: Add target-aware linking for BMPs (#168)

* sw: Add target-aware linking for BMPs

* docs/sw.md: Document target-aware linking of BMPs

docs/um/sw.md

@@ -22,7 +22,11 @@ To build a baremetal program (here `sw/tests/helloworld.c`) executing from the S
 make sw/tests/helloworld.spm.elf
 ```
 
-To create the same program executing from DRAM, `sw/tests/helloworld.spm.dram` can instead be built from the same source. Depending on their assumptions and behavior, not all programs may be built to execute from both locations.
+To create the same program executing from DRAM, `sw/tests/helloworld.dram.elf` can instead be built from the same source.
+
+Not all BMPs may be designed to be linked in multiple ways like `helloworld` above is. Linking is controlled by the linker scripts in `sw/link`. By convention, BMP main source files with a suffix are intended to only be linked with the corresponding script; for example, `sw/tests/dma_2d.spm.c` should only be linked against SPM using `sw/link/spm.ld`.
+
+When building BMPs, the toolchain will strip any suffixes corresponding to existing linker scripts. When running `make sw-all`, tests in `sw/tests` will be built only for their intended linking targets. Tests without suffixes, like `helloworld`, are assumed to be agnostic and will be built for all linking targets.
 
 ## Boot Flow
 

sw/sw.mk

@@ -100,14 +100,21 @@ CHS_SW_GEN_HDRS += $(OTPROOT)/.generated
 %.o: %.S $(CHS_SW_GEN_HDRS)
 	$(CHS_SW_CC) $(CHS_SW_INCLUDES) $(CHS_SW_CCFLAGS) -c $< -o $@
 
+# Programs may specify a linking mode in their name, e.g. `helloworld.spm.c`.
+# Tests with such infixes are built only for one linking mode, tests without them for all
 define chs_sw_ld_elf_rule
 .PRECIOUS: %.$(1).elf
 
 %.$(1).elf: $$(CHS_SW_LD_DIR)/$(1).ld %.o $$(CHS_SW_LIBS)
 	$$(CHS_SW_CC) $$(CHS_SW_INCLUDES) -T$$< $$(CHS_SW_LDFLAGS) -o $$@ $$*.o $$(CHS_SW_LIBS)
+
+%.$(1).elf: $$(CHS_SW_LD_DIR)/$(1).ld %.$(1).o $$(CHS_SW_LIBS)
+	$$(CHS_SW_CC) $$(CHS_SW_INCLUDES) -T$$< $$(CHS_SW_LDFLAGS) -o $$@ $$*.$(1).o $$(CHS_SW_LIBS)
 endef
 
-$(foreach link,$(patsubst $(CHS_SW_LD_DIR)/%.ld,%,$(wildcard $(CHS_SW_LD_DIR)/*.ld)),$(eval $(call chs_sw_ld_elf_rule,$(link))))
+CHS_SW_LINK_MODES ?= $(patsubst $(CHS_SW_LD_DIR)/%.ld,%,$(wildcard $(CHS_SW_LD_DIR)/*.ld))
+
+$(foreach link,$(CHS_SW_LINK_MODES),$(eval $(call chs_sw_ld_elf_rule,$(link))))
 
 %.dump: %.elf
 	$(CHS_SW_OBJDUMP) -d -S $< > $@
@@ -158,11 +165,24 @@ $(CHS_SW_DIR)/boot/linux.%.gpt.bin: $(CHS_SW_DIR)/boot/zsl.rom.bin $(CHS_SW_DIR)
 # Tests #
 #########
 
-CHS_SW_TEST_SRCS_S  	= $(wildcard $(CHS_SW_DIR)/tests/*.S)
-CHS_SW_TEST_SRCS_C     	= $(wildcard $(CHS_SW_DIR)/tests/*.c)
-CHS_SW_TEST_DRAM_DUMP  	= $(CHS_SW_TEST_SRCS_S:.S=.dram.dump) $(CHS_SW_TEST_SRCS_C:.c=.dram.dump)
-CHS_SW_TEST_SPM_DUMP   	= $(CHS_SW_TEST_SRCS_S:.S=.spm.dump)  $(CHS_SW_TEST_SRCS_C:.c=.spm.dump)
-CHS_SW_TEST_SPM_ROMH   	= $(CHS_SW_TEST_SRCS_S:.S=.rom.memh)  $(CHS_SW_TEST_SRCS_C:.c=.rom.memh)
-CHS_SW_TEST_SPM_GPTH   	= $(CHS_SW_TEST_SRCS_S:.S=.gpt.memh)  $(CHS_SW_TEST_SRCS_C:.c=.gpt.memh)
+# Accumulate single-link-mode sources and corresponding .dump targets
+define chs_sw_tests_add_rule
+BLA += $(wildcard $(2)/*.$(1).c)
+CHS_SW_TEST_LONE += $(wildcard $(2)/*.$(1).c) $(wildcard $(2)/*.$(1).S)
+CHS_SW_TEST_DUMP += $(patsubst %.c,%.dump,$(wildcard $(2)/*.$(1).c)) $(patsubst %.S,%.dump,$(wildcard $(2)/*.$(1).S))
+endef
+
+# Accumulate tests for all link modes
+$(foreach link,$(CHS_SW_LINK_MODES),$(eval $(call chs_sw_tests_add_rule,$(link),$(CHS_SW_DIR)/tests)))
+
+# Collect mode-agnostic tests, which should be build for all modes, and their .dump targets
+CHS_SW_TEST_C_LALL = $(filter-out $(CHS_SW_TEST_LONE), $(wildcard $(CHS_SW_DIR)/tests/*.c))
+CHS_SW_TEST_S_LALL = $(filter-out $(CHS_SW_TEST_LONE), $(wildcard $(CHS_SW_DIR)/tests/*.S))
+$(foreach link,$(CHS_SW_LINK_MODES),$(eval CHS_SW_TEST_DUMP += $(CHS_SW_TEST_C_LALL:.c=.$(link).dump) $(CHS_SW_TEST_S_LALL:.S=.$(link).dump)))
+
+# Generate .memh targets for ROM-linked tests
+CHS_SW_TEST_ROM_DUMP = $(filter %.rom.dump,$(CHS_SW_TEST_DUMP))
+CHS_SW_TESTS += $(CHS_SW_TEST_ROM_DUMP:.rom.dump=.rom.memh) $(CHS_SW_TEST_ROM_DUMP:.rom.dump=.gpt.memh)
 
-CHS_SW_TESTS = $(CHS_SW_TEST_DRAM_DUMP) $(CHS_SW_TEST_SPM_DUMP) $(CHS_SW_TEST_SPM_ROMH) $(CHS_SW_TEST_SPM_GPTH)
+# Add all dumps to test build
+CHS_SW_TESTS += $(CHS_SW_TEST_DUMP)