Re: [Qemu-devel] [PATCH V8 4/4] tests: Add migration test for aarch64

[Wei Huang <wehuang@redhat.com>]

----- Original Message -----
> From: "Andrew Jones" <drjones@redhat.com>
> To: "Wei Huang" <wei@redhat.com>
> Cc: qemu-devel@nongnu.org, lvivier@redhat.com, "peter maydell" <peter.maydell@linaro.org>, quintela@redhat.com,
> dgilbert@redhat.com
> Sent: Monday, September 3, 2018 6:53:35 AM
> Subject: Re: [Qemu-devel] [PATCH V8 4/4] tests: Add migration test for aarch64
> 
> On Sat, Sep 01, 2018 at 01:11:15AM -0400, Wei Huang wrote:
> > +.section .text
> > +
> > +        .globl  _start
> > +
> > +_start:
> > +        /* disable MMU to use phys mem address */
> > +        mrs     x0, sctlr_el1
> > +        bic     x0, x0, #(1<<0)
> > +        msr     sctlr_el1, x0
> > +        isb
> > +
> > +        /* traverse test memory region */
> > +        mov     x0, #ARM_TEST_MEM_START
> > +        mov     x1, #ARM_TEST_MEM_END
> 
> I don't think there's any reason to require the start and
> end addresses to be hard coded. We should be able to get
> the start address with

Are you saying that we should make the .S file as independent as possible? These variables need to be defined for migration-test.c anyway. Why can't we just use them here?

> 
> #define KERNEL_OFFSET 0x80000
>            adr     x0, _start
>            add     x0, x0, #(1024 * 1024 - KERNEL_OFFSET)
> 
> and the end address with
> 
>            add     x1, x0, #(99 * 1024 * 1024)
> 
> Thanks,
> drew
>