GNU as ld flags for assembly on NetBSD for arm

Question

I am trying to assemble a simple Hello World program with the GNU assembler (as) on a Raspberry Pi 3 B+ running NetBSD 9.1
What flags do I need to add to as or ld to make them assemble the code correctly for the architecture I am using?

$ as -o hllwrld.o hllwrld.s
$ ld -o hllwrld hllwrld.o
$ ./hllwrld
-sh: Cannot execute ELF binary ./hllwrld

$ uname -a
NetBSD rpi 9.1 NetBSD 9.1 (RPI) #0: Sun Oct 18 19:24:30 UTC 2020  [email protected]:/usr/src/sys/arch/evbarm/compile/RPI evbarm

Is this aarch64 or arm64?

I know there are man pages but I am just learning assembly so I have no idea what configurations/flags/arguments I even need to be looking for.

Thanks for any help.

Answer 1

This may be failing for a number of reasons, all of which come down to missing arguments and/or flags to ld and may include runtime linker information, startup code, and libraries.

Give this a try for a hint and see what's happing behind the scenes:

$ cc -v -o hllwrld hllwrld.o

Answer 2

The answer by Klaus should give enough clues about specifics for your system, but you might also want to look at a working example for NetBSD/i386 and amd64:

github.com/robohack/experiments: thello.s

If you open the file in emacs and approve the local variables settings then the compile-command will be set to a command line that will assemble, link, and run, the example program on a compatible NetBSD system.