[U-Boot] uImage load address and entry point with Minnowboard

[vinoth eswaran]

On Fri, Jun 24, 2016 at 1:57 PM, Wolfgang Denk <wd at denx.de> wrote:
> Dear Vinoth,
>
> In message <CAJst-kFZjA_Nq7K25CEPri9Aq7r=-mmtGyeNYwwg-P2CrN4dbA at mail.gmail.com> you wrote:
>>
>> I am using the following command to create uImage. Here in the architecture
>> argument I am not seeing any option corresponding to the Intel-x86_64. So I
>> had used x86, which I am not sure is valid or not. The kernel is 64 bit.
>>
>> mkimage -A x86 -O linux -T kernel -C none -a 0x100000 -e 0x00000 -n Linux
>> -d vmlinux-4.4.6-ina uImage
>> Image Name:   Linux
>> Created:      Fri Jun 24 10:35:40 2016
>> Image Type:   Intel x86 Linux Kernel Image (uncompressed)
>> Data Size:    21966248 Bytes = 21451.41 kB = 20.95 MB
>> Load Address: 00100000
>> Entry Point:  00000000
>
> This makes no sense to me.  When the kernel image is loaded to RAM
> starting at address 0x00100000, then ther eis no valid code at address
> 0x00000000.  So 0x00000000 cannot be a valid entry oint address.  The
> entry point address must be somewhare in the range between "load
> address" and "load address + size of uncompressed kernel image".

Dear Mr.Simon Glass,

 Could you please explain how the load address and entry address work
in x86. I am using the same address as defined in image.its and still
could run the Linux kernel.

Defined in image.its file:
        kernel at 1 {
            description = "Vanilla Linux kernel";
            data = /incbin/("./vmlinux.bin");
            type = "kernel";
            arch = "x86_64";
            os = "linux";
            compression = "none";
            load = <0x01000000>;
            entry = <0x00000000>;
}

As pointed out by Mr.Wolfgang it doesn't make sense, as the kernel is
loaded at the address '0x01000000' and entry is '0x0000000'. Or in
x86_64 arch these addresses are stored in setup.bin files and loaded
at run time?

Regards,
Vinothkumar

>> Error: Invalid Boot Flag (found 0x0000, expected 0xaa55)
>> Setup at 0x000000
>> Magic signature not found
>>
>> Is is I need to load setup.bin also?
>
> I have no idea.  I didn't know that you were asking for x86...  I'm
> not an expert in this area.  I added Simon and Bin to cc: who might be
> in a much better position to answer such a question.
>
>
> Best regards,
>
> Wolfgang Denk
>
> --
> DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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