Re: [kvm-unit-tests PATCH v2 2/6] s390x: Make tests bootable from disk

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 05.12.18 16:39, 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.
> 
> Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
> ---
>  s390x/cstart64.S | 9 ++++++++-
>  s390x/flat.lds   | 8 +++++++-
>  2 files changed, 15 insertions(+), 2 deletions(-)
> 
> diff --git a/s390x/cstart64.S b/s390x/cstart64.S
> index dc7ddd6..d382497 100644
> --- a/s390x/cstart64.S
> +++ b/s390x/cstart64.S
> @@ -14,9 +14,16 @@
>  
>  .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.
> + *
> + * For KVM and TCG kernel boot we are in 64 bit z/Arch mode.
> + * When booting from disk the initial short psw is in 31 bit mode.
> + */
>  	.globl start
>  start:
> +	sam64				# Set addressing mode to 64 bit
>  	/* setup stack */
>  	larl	%r15, stackptr
>  	/* setup initial PSW mask + control registers*/
> 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;

Can you add a comment here describing what this is and what it does?
(31bit PSW jumping to start to be used for booting from disk)

> +		 LONG(0x00080000)
> +		 LONG(0x80010000)
> +	}
> +	. = 0x10000;
>  	.text : {
>  		*(.init)
>  		. = 0x480;
>  		ipl_args = .;
> -		. = 0x600;
> +		.  = 0x1000;

Can you give me a hint why that change is needed?

>  		*(.text)
>  		*(.text.*)
>  	}
> 


-- 

Thanks,

David / dhildenb



[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]

  Powered by Linux