Re: [qemu-s390x] [kvm-unit-tests PATCH 1/5] s390x: Make tests bootable from disk

[David Hildenbrand]

On 04.12.18 14:48, Janosch Frank wrote:
> Currently tests are run with the --kernel option of Qemu, which will
> load the ELF file and jump to the start address. When booting from
> disk, we need to specify a start address. This is done by setting the
> initial short PSW at 0x0.
> 
> For later compatibility with other hypervisors the short psw has 31
> bit addressing specified.
> 
> Signed-off-by: Janosch Frank <address@hidden>
> ---
>  s390x/cstart64.S | 9 +++++++--
>  s390x/flat.lds   | 8 +++++++-
>  2 files changed, 14 insertions(+), 3 deletions(-)
> 
> diff --git a/s390x/cstart64.S b/s390x/cstart64.S
> index dc7ddd6..abd6b58 100644
> --- a/s390x/cstart64.S
> +++ b/s390x/cstart64.S
> @@ -14,12 +14,17 @@
>  
>  .section .init
>  
> -/* entry point - for KVM + TCG we directly start in 64 bit mode */
> +/*
> + * Short init between 0x10000 and 0x10480 and then jump to 0x11000.
> + * 0x10480 - 0x11000 are written to by bootloader.
> + */
>       .globl start
>  start:
> +     sam64                           # Set addressing mode to 64 bit

I guess this was supposed to go into patch #2?

> +start64:
>       /* setup stack */
>       larl    %r15, stackptr
> -     /* setup initial PSW mask + control registers*/
> +     /* setup initial PSW mask + control registers */
>       larl    %r1, initial_psw
>       lpswe   0(%r1)
>  init_psw_cont:
> diff --git a/s390x/flat.lds b/s390x/flat.lds
> index b6e2172..7cfd9f9 100644
> --- a/s390x/flat.lds
> +++ b/s390x/flat.lds
> @@ -1,10 +1,16 @@
>  SECTIONS
>  {
> +     .lowcore : {
> +             . = 0;
> +              LONG(0x00080000)
> +              LONG(0x80010000)
> +     }
> +     . = 0x10000;
>       .text : {
>               *(.init)
>               . = 0x480;
>               ipl_args = .;
> -             . = 0x600;
> +             .  = 0x1000;
>               *(.text)
>               *(.text.*)
>       }
> 


-- 

Thanks,

David / dhildenb