base-hw: RISC-V BBL

The Berkley Boot Loader handles kernel loading and machine mode

tool/run/image/bbl

@@ -0,0 +1,6 @@
+proc run_image {elf_img} {
+	puts "using '$elf_img' as bbl image"
+
+	exec rm -f bbl/image.o
+	exec make IMAGE_ELF=[pwd]/$elf_img bbl
+}