Re: [Qemu-devel] [PATCH] Fix -kernel on target-ppc

[Aurelien Jarno]

On Sat, Jan 24, 2009 at 09:58:35PM +0100, Alexander Graf wrote:
> OpenBIOS searches for the preloaded kernel at 0x1000000, so let's
> put it there instead of an invalid location.

Your patch is actually wrong, the second argument of load_elf() is an
offset to the physical address (as found in the elf header), and not a
load address. 

By chance the physical address of a >= 2.6.25 kernel is 0x00000000, so
your patch works. But it will break supports for < 2.6.25 kernel as
their physical address is 0xc0000000. Not that they are only the default
values, they can be changed in the .config file.

I have already proposed a patch to use the virtual address of the elf
header as done by yaboot or quik, but I have been told it is actually
wrong.

We have to find another way to load the elf file at a fixed address.

> Using this patch I was able to use -kernel for a current openSUSE
> 11.1 kernel.
> 
> Signed-off-by: Alexander Graf <address@hidden>
> ---
>  hw/ppc_oldworld.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/hw/ppc_oldworld.c b/hw/ppc_oldworld.c
> index 042a40f..0af2436 100644
> --- a/hw/ppc_oldworld.c
> +++ b/hw/ppc_oldworld.c
> @@ -209,7 +209,7 @@ static void ppc_heathrow_init (ram_addr_t ram_size, int 
> vga_ram_size,
>      if (linux_boot) {
>          kernel_base = KERNEL_LOAD_ADDR;
>          /* now we can load the kernel */
> -        kernel_size = load_elf(kernel_filename, kernel_base - 0xc0000000ULL,
> +        kernel_size = load_elf(kernel_filename, KERNEL_LOAD_ADDR,
>                                 NULL, NULL, NULL);
>          if (kernel_size < 0)
>              kernel_size = load_aout(kernel_filename, kernel_base,
> -- 
> 1.6.0.2
> 
> 
> 
> 

-- 
Aurelien Jarno                          GPG: 1024D/F1BCDB73
address@hidden                 http://www.aurel32.net