add ExampleTopWithBlockDevice and tests

tests/Makefile

@@ -3,7 +3,7 @@ OBJDUMP=riscv64-unknown-elf-objdump
 CFLAGS=-mcmodel=medany -std=gnu99 -O2 -fno-common -fno-builtin-printf
 LDFLAGS=-static -nostdlib -nostartfiles -lgcc
 
-PROGRAMS = pwm
+PROGRAMS = pwm blkdev
 
 default: $(addsuffix .riscv,$(PROGRAMS))
 
@@ -15,8 +15,8 @@ dumps: $(addsuffix .dump,$(PROGRAMS))
 %.o: %.c mmio.h
 	$(GCC) $(CFLAGS) -c $< -o $@
 
-%.riscv: %.o crt.o syscalls.o
-	$(GCC) -T link.ld $(LDFLAGS) $^ -o $@
+%.riscv: %.o crt.o syscalls.o link.ld
+	$(GCC) -T link.ld $(LDFLAGS) $< crt.o syscalls.o -o $@
 
 %.dump: %.riscv
 	$(OBJDUMP) -D $< > $@