Re: Question on BIGGEST_ALIGNMENT in GCC on NetBSD/m68k

On 16/06/2025 13:10, John Paul Adrian Glaubitz wrote:
> On Mon, 2025-06-16 at 13:05 +0200, Laurent Vivier wrote:
>> I think an e_flags with a new value like EF_M68K_ABI2 would be more appropriate.
> 
> How is it currently used on m68k and does QEMU use it? I think that would be
> certainly a way to go.
> 

It's not used by m68k.

It's only used by MIPS.

In QEMU see linux-user/elfload.c:

#ifdef TARGET_ABI_MIPSN32
#define elf_check_abi(x) ((x) & EF_MIPS_ABI2)
#else
#define elf_check_abi(x) (!((x) & EF_MIPS_ABI2))
#endif

#ifndef elf_check_abi
#define elf_check_abi(x) (1)
#endif

/* Verify the portions of EHDR outside of E_IDENT for the target.
    This has to wait until after bswapping the header.  */
static bool elf_check_ehdr(struct elfhdr *ehdr)
{
     return (elf_check_arch(ehdr->e_machine)
             && elf_check_abi(ehdr->e_flags)
             && ehdr->e_ehsize == sizeof(struct elfhdr)
             && ehdr->e_phentsize == sizeof(struct elf_phdr)
             && (ehdr->e_type == ET_EXEC || ehdr->e_type == ET_DYN));
}
...

static void load_elf_image(const char *image_name, const ImageSource *src,
                            struct image_info *info, struct elfhdr *ehdr,
                            char **pinterp_name)
...
     if (!elf_check_ehdr(ehdr)) {
         error_setg(&err, "Invalid ELF image for this architecture");
         goto exit_errmsg;
     }
...

Thanks,
Laurent