On Mon, Oct 6, 2025 at 7:33 PM Philippe Mathieu-Daudé <[email protected]>
wrote:
> MicroBlaze CPU model has a "little-endian" property, pointing to
> the @endi internal field. Commit c36ec3a9655 ("hw/microblaze:
> Explicit CPU endianness") took care of having all MicroBlaze
> boards with an explicit default endianness, so later commit
> 415aae543ed ("target/microblaze: Consider endianness while
> translating code") could infer the endianness at runtime from
> the @endi field, and not a compile time via the TARGET_BIG_ENDIAN
> definition. Doing so, we forgot to make the endianness explicit
> on user emulation, so there all CPUs are started with the default
> "little-endian=off" value, leading to breaking support for little
> endian binaries:
>
> $ readelf -h ./hello-world-mbel
> ELF Header:
> Magic: 7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
> Class: ELF32
> Data: 2's complement, little endian
>
> $ qemu-microblazeel ./hello-world-mbel
> qemu: uncaught target signal 11 (Segmentation fault) - core dumped
> Segmentation fault (core dumped)
>
> Fix by restoring the previous behavior of starting with the
> builtin endianness of the binary:
>
> $ qemu-microblazeel ./hello-world-mbel
> Hello World
>
> Cc: [email protected]
> Fixes: 415aae543ed ("target/microblaze: Consider endianness while
> translating code")
> Reported-by: Edgar E. Iglesias <[email protected]>
> Signed-off-by: Philippe Mathieu-Daudé <[email protected]>
>
Reviewed-by: Edgar E. Iglesias <[email protected]>
> ---
> linux-user/microblaze/elfload.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/linux-user/microblaze/elfload.c
> b/linux-user/microblaze/elfload.c
> index 7eb1b26d170..bdc0a953d59 100644
> --- a/linux-user/microblaze/elfload.c
> +++ b/linux-user/microblaze/elfload.c
> @@ -8,7 +8,8 @@
>
> const char *get_elf_cpu_model(uint32_t eflags)
> {
> - return "any";
> + return TARGET_BIG_ENDIAN ? "any,little-endian=off"
> + : "any,little-endian=on";
> }
>
> void elf_core_copy_regs(target_elf_gregset_t *r, const CPUMBState *env)
> --
> 2.51.0
>
>
