Re: [RFC PATCH v3 1/5] ppc64: Add semihosting support

[Peter Maydell]

On Mon, 18 Apr 2022 at 20:15, Leandro Lupori
<leandro.lupori@eldorado.org.br> wrote:
>
> Add semihosting support for PPC64. This implementation is
> based on the standard for ARM semihosting version 2.0, as
> implemented by QEMU and documented in
>
>     https://github.com/ARM-software/abi-aa/releases
>
> The PPC64 specific differences are the following:
>
> Semihosting Trap Instruction: sc 7
> Operation Number Register: r3
> Parameter Register: r4
> Return Register: r3
> Data block field size: 64 bits
>
> +static inline bool
> +common_semi_sys_exit_extended(CPUState *cs, int nr)
> +{
> +    return (nr == TARGET_SYS_EXIT_EXTENDED || sizeof(target_ulong) == 8);
> +}

Does the PPC specification for semihosting really follow the
legacy Arm requirement that the 32-bit version of the EXIT
call doesn't let the caller specify the exit status? It's
not a very sensible choice IMHO if you don't have the legacy
baggage to deal with.

-- PMM