Re: [PATCH] linux-user/mips: Low down switchable NaN2008 requirement

[Jiaxun Yang]

Ping？

> 2023年2月11日 17:34，Jiaxun Yang <jiaxun.yang@flygoat.com> 写道：
> 
> Previously switchable NaN2008 requires fcsr31.nan2008 to be writable
> for guest. However as per MIPS arch spec this bit can never be writable.
> This cause NaN2008 ELF to be rejected by QEMU.
> 
> NaN2008 can be enabled on R2~R5 processors, just make it available
> unconditionally.
> 
> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> ---
> linux-user/mips/cpu_loop.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/linux-user/mips/cpu_loop.c b/linux-user/mips/cpu_loop.c
> index d5c1c7941d..b5c2ca4a3e 100644
> --- a/linux-user/mips/cpu_loop.c
> +++ b/linux-user/mips/cpu_loop.c
> @@ -301,8 +301,7 @@ void target_cpu_copy_regs(CPUArchState *env, struct 
> target_pt_regs *regs)
>     }
>     if (((info->elf_flags & EF_MIPS_NAN2008) != 0) !=
>         ((env->active_fpu.fcr31 & (1 << FCR31_NAN2008)) != 0)) {
> -        if ((env->active_fpu.fcr31_rw_bitmask &
> -              (1 << FCR31_NAN2008)) == 0) {
> +        if (!(env->insn_flags & ISA_MIPS_R2)) {
>             fprintf(stderr, "ELF binary's NaN mode not supported by CPU\n");
>             exit(1);
>         }
> -- 
> 2.37.1 (Apple Git-137.1)
>