[U-Boot] Installing u-boot for x86 (non EFI) on a disk

[Bin Meng]

Hi Igor,

On Wed, Aug 12, 2015 at 5:54 PM, Stoppa, Igor <igor.stoppa at intel.com> wrote:
> Hi Bin Meng,
> thanks for your reply, please find few comments inlined below.
>
> On 11 August 2015 at 17:09, Bin Meng <bmeng.cn at gmail.com> wrote:
>> Hi Igor,
>>
>> On Tue, Aug 11, 2015 at 9:18 PM, Stoppa, Igor <igor.stoppa at intel.com> wrote:
>
>> U-Boot supports running bare-metal as well as being loaded as a
>> coreboot payload. For the base-metal case, U-Boot is the actual BIOS
>> which boots from the x86 reset vector.
>
> ok, thanks for the explanation.
> This case probably will not work for me, as I don't think I am allowed
> to reprogram the BIOS of the machine(s) I'm targeting.
>

And I believe your machine's BIOS is not coreboot, so kind of stuck.

> [...]
>
>>> However I would like to create a loop file, install u-boot in it and
>>> pass that file to qemu as hda, rather than using the rom file.
>>>
>>
>> Why do you want to do this way? U-Boot does not support this use case so far.
>
> I wrongly had the impression that it was supported.
> Thanks again for the clarification.
> The reason I wanted to do it, was to get familiar with the U-Boot
> build process and see the differences vs the EFI mode.

In your first email, you said you were running U-Boot on QEMU. You can
try U-Boot on QEMU to get familiar with U-Boot build process. There is
no need for you to get a real x86 board as QEMU is pretty easy to
configure and use.

>
> So, with the constraint that I have to not modify the existing BIOS,
> it seems that the only way to put U-Boot on a disk image for x86 is to
> use U-Boot as EFI payload.
>
> Is this correct?
>

Yes, this is correct. If your BIOS is an EFI BIOS, you can try EFI
payload. But right now you can only try the EFI payload on MinnowMax
and QEMU as the EFI payload. There is another way of testing U-Boot on
top of EFI which is to build U-Boot as an EFI application. Please
check doc/README.efi for the information.

Regards,
Bin