Re: [Qemu-devel] [PATCH] target-arm: Load ELF images with the correct machine type for CPU

[Alexander Graf]

On 21.03.14 19:44, Peter Maydell wrote:
> When trying to load an ELF file specified via -kernel, we need to
> pass load_elf() the ELF machine type corresponding to the CPU we're
> booting with, not the one corresponding to the softmmu binary
> we happen to be running. (The two are different in the case of
> loading a 32-bit ARM ELF file into a 32 bit CPU being emulated
> by qemu-system aarch64.) This was causing us to incorrectly fail
> to load ELF images in this situation.
>
> Signed-off-by: Peter Maydell <address@hidden>
> ---
> This isn't really a big deal since we can just say "use the
> qemu-system-arm binary instead". However maybe we should put
> this into 2.0. Opinions?
>
> Incidentally I suspect hw/i386/multiboot.c has a similar
> problem where it calls load_elf() passing ELF_MACHINE.

We have some compatibility code in the elf loader that says "if 
elf_machine == ppc64, then allow loading of ppc32 binaries too":

http://git.qemu.org/?p=qemu.git;a=blob;f=include/hw/elf_ops.h;h=c6b5129bab394704cf2197fe079ab195ec84ec2a;hb=HEAD#l213

which we need because our mac99 firmware is 32bit, but does know how to 
drive a ppc64 CPU. I suppose your case is slightly different for AArch64 
which is not compatible with 32bit binaries on firmware level.


Alex