Re: [PATCH v2 08/30] bsd-user/arm/target_arch_cpu.h: Implement trivial EXCP exceptions

[Warner Losh <imp@bsdimp.com>]

[-- Attachment #1: Type: text/plain, Size: 1766 bytes --]

On Tue, Nov 2, 2021 at 9:17 PM Richard Henderson <
richard.henderson@linaro.org> wrote:

> On 11/2/21 6:52 PM, Warner Losh wrote:
> > +        case EXCP_UDEF:
> > +            {
> > +                /* See arm/arm/undefined.c undefinedinstruction(); */
> > +                info.si_addr = env->regs[15];
> > +
> > +                /*
> > +                 * Make sure the PC is correctly aligned. (It should
> > +                 * be.)
> > +                 */
> > +                if ((info.si_addr & 3) != 0) {
> > +                    info.si_signo = TARGET_SIGILL;
> > +                    info.si_errno = 0;
> > +                    info.si_code = TARGET_ILL_ILLADR;
> > +                    queue_signal(env, info.si_signo, &info);
>
> You won't need this; unaligned pc will raise a different exception.
>

Dropped.


> > +                } else {
> > +                    int rc = 0;
> > +#ifdef NOT_YET
> > +                    uint32_t opcode;
> > +
> > +                    /*
> > +                     * Get the opcode.
> > +                     *
> > +                     * FIXME - what to do if get_user() fails?
> > +                     */
> > +                    get_user_u32(opcode, env->regs[15]);
> > +
> > +                    /* Check the opcode with CP handlers we may have. */
> > +                    rc = EmulateAll(opcode, &ts->fpa, env);
> > +#endif /* NOT_YET */
>
> Drop this til you need it.  Even then, we prefer to emulate all insns in
> the front-end.
> We can talk about what changes need to happen such that the actual CP
> registers are simply
> available at EL0.  I suspect they've already been done for linux-user
> anyway...
>

Dropped, reformatted and added a TODO comment.

Both will be in the next spin.

Thanks!

Warner

[-- Attachment #2: Type: text/html, Size: 2786 bytes --]