Re: [PATCH v3 11/13] target/hexagon: Add an errno mapping

On Mon, 17 Aug 2026 06:41:28 +0200 =?UTF-8?Q?Philippe_Mathieu-Daud=C3=A9?= <[email protected]> wrote:
>
> On 20/7/26 19:41, Matheus Tavares Bernardino wrote:
> > From: Brian Cain <[email protected]>
> > 
> > The Hexagon semihosting ABI defines its own errno values
> > which may differ from the host's.  Translate host errno to
> > the Hexagon-specific values before returning results to the
> > guest so that baremetal programs see the expected error codes.
> > 
> > Signed-off-by: Brian Cain <[email protected]>
> > Reviewed-by: Pierrick Bouvier <[email protected]>
> > Signed-off-by: Matheus Tavares Bernardino <[email protected]>
> > ---
> >   target/hexagon/hexswi.c | 75 ++++++++++++++++++++++++++++++++++-------
> >   1 file changed, 63 insertions(+), 12 deletions(-)
> > 
> > diff --git a/target/hexagon/hexswi.c b/target/hexagon/hexswi.c
> > index 564a11e557a..d93789e39c7 100644
> > --- a/target/hexagon/hexswi.c
> > +++ b/target/hexagon/hexswi.c
> > @@ -154,12 +154,63 @@ static void do_preload(CPUHexagonState *env, target_ulong swi_info, bool load)
> >       hexagon_peek_memory_range(env, addr, count, retaddr);
> >   }
> >   
> > +/* Hexagon semihosting errno values */
> > +#define HEX_EINVAL          22
> > +#define HEX_ERRNOS \
> > +    HEX_ERRNO(EPERM,        1) \
> > +    HEX_ERRNO(ENOENT,       2) \
> > +    HEX_ERRNO(EINTR,        4) \
> > +    HEX_ERRNO(EIO,          5) \
> > +    HEX_ERRNO(ENXIO,        6) \
> > +    HEX_ERRNO(EBADF,        9) \
> > +    HEX_ERRNO(EAGAIN,       11) \
> > +    HEX_ERRNO(ENOMEM,       12) \
> > +    HEX_ERRNO(EACCES,       13) \
> > +    HEX_ERRNO(EFAULT,       14) \
> > +    HEX_ERRNO(EBUSY,        16) \
> > +    HEX_ERRNO(EEXIST,       17) \
> > +    HEX_ERRNO(EXDEV,        18) \
> > +    HEX_ERRNO(ENODEV,       19) \
> > +    HEX_ERRNO(ENOTDIR,      20) \
> > +    HEX_ERRNO(EISDIR,       21) \
> > +    HEX_ERRNO(EINVAL,       HEX_EINVAL) \
> > +    HEX_ERRNO(ENFILE,       23) \
> > +    HEX_ERRNO(EMFILE,       24) \
> > +    HEX_ERRNO(ENOTTY,       25) \
> > +    HEX_ERRNO(ETXTBSY,      26) \
> > +    HEX_ERRNO(EFBIG,        27) \
> > +    HEX_ERRNO(ENOSPC,       28) \
> > +    HEX_ERRNO(ESPIPE,       29) \
> > +    HEX_ERRNO(EROFS,        30) \
> > +    HEX_ERRNO(EMLINK,       31) \
> > +    HEX_ERRNO(EPIPE,        32) \
> > +    HEX_ERRNO(ERANGE,       34) \
> > +    HEX_ERRNO(ENAMETOOLONG, 36) \
> > +    HEX_ERRNO(ENOSYS,       38) \
> > +    HEX_ERRNO(ELOOP,        40) \
> > +    HEX_ERRNO(EOVERFLOW,    75)
> > +
> > +/* Map host errno to hexagon semihosting errno */
> > +static void semi_cb(CPUState *cs, uint64_t ret, int err)
> > +{
> > +#define HEX_ERRNO(NAME, CODE) case NAME: err = CODE; break;
> > +    switch (err) {
> > +    case 0:
> > +        break;
> > +    HEX_ERRNOS
> 
> IMHO defining the target-specific semihosting values as TARGET_foo
> like done in target/xtensa/xtensa-semi.c is more readable long-term.

The idea behind the HEX_ERRNOS macro here was to avoid too much repetition.
But I agree, if it turns it less readable long term, let's go with the
enum + switch/case.

> > +    default:
> > +        err = HEX_EINVAL;
> > +        break;
> > +    }
> > +    common_semi_cb(cs, ret, err);
> > +}
> 
>