Re: [PATCH] move the kernel to 16MB for NUMA-Q

[Rene Herman <rene.herman@gmail.com>]

On 06/11/2007 10:07 PM, Rene Herman wrote:

> But, it's just a default anyway. Would it be considered beneficial to 
> more explicitly provide a few options through a config menu, something 
> like the attached?

Ehm, so now where did that long help actually end up? :-|

If the notion is considered okay, this wants someone with a little more 
Kconfig insight it seems.

> diff --git a/arch/i386/Kconfig b/arch/i386/Kconfig
> index 8770a5d..6737529 100644
> --- a/arch/i386/Kconfig
> +++ b/arch/i386/Kconfig
> @@ -813,9 +813,10 @@ config CRASH_DUMP
>            PHYSICAL_START.
>  	  For more details see Documentation/kdump/kdump.txt
>  
> -config PHYSICAL_START
> -	hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
> -	default "0x100000"
> +choice
> +	depends on EMBEDDED || CRASH_DUMP
> +	prompt "Physical address where the kernel is loaded"
> +	default PHYSICAL_START_1M
>  	help
>  	  This gives the physical address where the kernel is loaded.
>  
> @@ -854,6 +855,40 @@ config PHYSICAL_START
>  
>  	  Don't change this unless you know what you are doing.
>  
> +	config PHYSICAL_START_1M
> +		bool "1M"
> +		help
> +		  Choose this to load the kernel at the standard 1M address.
> +
> +	config PHYSICAL_START_4M
> +		bool "4M"
> +		help
> +		  Loading the kernel at a 4M aligned physical address can
> +		  make for a slightly faster kernel.
> +
> +		  Choose this if you have 8M or more installed.
> +
> +	config PHYSICAL_START_16M
> +		bool "16M"
> +		help
> +		  Loading the kernel at a 4M aligned physical address can
> +		  make for a slightly faster kernel.
> +
> +		  Additionally, loading it at 16M gets it out of the legacy
> +		  DMA zone which you might consider beneficial if you use
> +		  devices doing legacy DMA (such as a floppy drive, an ECP
> +		  parallel port or DMA capable ISA peripherals).
> +
> +		  Choose this if you have 20M or more installed and a need
> +		  for legacy DMA.
> +endchoice
> +
> +config PHYSICAL_START
> +	hex
> +	default "0x100000" if PHYSICAL_START_1M
> +	default "0x400000" if PHYSICAL_START_4M
> +	default "0x1000000" if PHYSICAL_START_16M
> +
>  config RELOCATABLE
>  	bool "Build a relocatable kernel(EXPERIMENTAL)"
>  	depends on EXPERIMENTAL

Rene.