[PATCH 4/11] powerpc: Add CONFIG_CRASH_DUMP

[Olaf Hering]

 On Sun, Dec 04, Michael Ellerman wrote:

> This patch adds a Kconfig variable, CONFIG_CRASH_DUMP, which configures the
> built kernel for use as a Kdump kernel.
> 
> Currently "all" this involves is changing the value of KERNELBASE to 32 MB.

> +++ kexec/include/asm-powerpc/page.h
> @@ -37,8 +37,15 @@
>   */
>  #define PAGE_MASK      (~((1 << PAGE_SHIFT) - 1))
>  
> +#ifdef CONFIG_CRASH_DUMP
> +/* Kdump kernel runs at 32 MB, change at your peril. */
> +#define PHYSICAL_START	0x2000000
> +#else
> +#define PHYSICAL_START	0x0
> +#endif
> +
>  #define PAGE_OFFSET     ASM_CONST(CONFIG_KERNEL_START)
> -#define KERNELBASE      PAGE_OFFSET
> +#define KERNELBASE      (PAGE_OFFSET + PHYSICAL_START)

This changes the vmlinux entry point, and breaks some assumptions in
yaboot. It wont load an initrd anymore, flat_vmlinux is always false.

It means also that a SLES9 installation cant load a SLES10 kernel+initrd via yaboot.
Fixing it now in my tree. 

-- 
short story of a lazy sysadmin:
 alias appserv=wotan