Re: Extending boot protocol & bzImage for paravirt_ops

Jeremy Fitzhardinge
2007-06-01T20:56:00Z

Eric W. Biederman wrote:
> ....
> +Field name: hardware_subarch
> +Type: write
> +Offset/size: 0x23c/4
> +Protocol: 2.07+
> +
> + In a paravirtualized environment the hardware low level architectural
> + pieces such as interrupt handling, page table handling, and
> + accessing process control registers needs to be done differently.
> +
> + This field allows the bootloader to inform the kernel we are in one
> + one of those environments.
> +
> + 0x00000000 The default x86/PC environment
> + 0x00000001 lguest
> + 0x00000002 Xen
> +
> +Field name: hardware_subarch_data
> +Type: write
> +Offset/size: 0x23c/8
>

offset = 240

> +Protocol: 2.07+
> +
> + A pointer to data that is specific to hardware subarch
>

Do we care particularly? If 8 bytes is enough for the subarch, do we
care whether its a pointer or literal? After all, this is just a private
channel between the bootloader and some subarch-specific piece of code
in the kernel.

J