Re: [PATCH] xen: arm: introduce uImage probe function for Dom0

[Julien Grall <julien.grall@linaro.org>]

Hi Oleksandr,

Thanks you for your patch,

On 19/08/14 05:37, Oleksandr Dmytryshyn wrote:
> Patch adds a possibility to boot dom0 kernel from uImage.
> This is needed to improve bootime. Comparing to zImage,

boot-time

> uImage is not packed, therefore we can save time needed
> to unpack.
>
> Change-Id: If92bc895721f0b2fa0a844bb92eddc8f1fdc5498
> Signed-off-by: Oleksandr Dmytryshyn <oleksandr.dmytryshyn@globallogic.com>
> ---
>   xen/arch/arm/kernel.c | 67 +++++++++++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 67 insertions(+)
>
> diff --git a/xen/arch/arm/kernel.c b/xen/arch/arm/kernel.c
> index d635a7e..45d92c9 100644
> --- a/xen/arch/arm/kernel.c
> +++ b/xen/arch/arm/kernel.c
> @@ -16,6 +16,12 @@
>
>   #include "kernel.h"
>
> +#define UIMAGE32_MAGIC_OFFSET 0x8
> +#define UIMAGE32_START_OFFSET 0x4
> +#define UIMAGE32_END_OFFSET   0x3

Can you define a structure as it's done for zImage64. It's easier to 
understand. Also, do you have any link to the uImage protocol?

A quick search doesn't allow me to find anything that match your format 
here.

[..]

> +    /*
> +     * Check for an appended DTB.
> +     */
> +    if ( addr + len + sizeof(dtb_hdr) <= size )
> +    {
> +        copy_from_paddr(&dtb_hdr, addr + len, sizeof(dtb_hdr));
> +
> +        if ( be32_to_cpu(dtb_hdr.magic) == DTB_MAGIC )
> +            len += be32_to_cpu(dtb_hdr.total_size);
> +
> +            if ( len - start > addr + size )
> +                return -EINVAL;
> +    }

This is a legacy on zImage, I don't really want to see it on 
implementation of a new format. Xen is creating the device tree for 
DOM0, the developer should not append a device tree.

-- 
Julien Grall