main: select shared object to run as payload via command line

Rest of the command line becomes arguments for the payload.

build.mak

@@ -77,6 +77,7 @@ loader.img: boot.bin loader.elf
 	$(call quiet, dd if=boot.bin of=$@ > /dev/null 2>&1, DD $@ boot.bin)
 	$(call quiet, dd if=loader.elf of=$@ conv=notrunc seek=128 > /dev/null 2>&1, \
 		DD $@ loader.elf)
+	$(call quiet, $(src)/scripts/imgedit.py setargs $@ java.so Hello, IMGEDIT $@)
 
 loader.bin: arch/x64/boot32.o arch/x64/loader32.ld
 	$(call quiet, $(LD) -nostartfiles -static -nodefaultlibs -o $@ \

loader.cc

@@ -289,9 +289,12 @@ void* do_main_thread(void *_args)
     debug(fmt("nanosleep(100000) -> %d") % (t2 - t1));
 
 //    load_tests(prog);
-    prog->add_object("java.so");
+    auto av = args->av;
+    auto ac = args->ac;
+    prog->add_object(av[0]);
+    ++av, --ac;
     auto main = prog->lookup_function<void (int, char**)>("main");
-    main(args->ac, args->av);
+    main(ac, av);
 
     while (true)
 	;