Re: [edk2-devel] [PATCH] MdeModulePkg/UefiBootManagerLib: Put BootMenu at the end of BootOrder

["Laszlo Ersek" <lersek@redhat.com>]

On 02/19/21 02:33, Li, Walon wrote:
> Hi Liming,
> 
> As edk2 design, any new boot options should be put at the end of BootOrder because these are NEW . That means system should "append" BootOrder instead of override original order.
> For example, if system has three boot options currently - Boot0001, Boot0002, Boot0003 and then one new option - Boot0000 will be added. The order should become Boot0001,Boot0002,Boot0003,Boot0000. However, in this case, BootmanagerMenu doesn't follow this rule. We set "zero" priority so system would put BootManagerMenu boot option at start.
> This case is a corner case because the symptom only be gotten when user delete BootManagerMenu on OS or EFI shell. But it's a possible case. For keeping behavior consistent, we should keep BootManagerMenu option behavior as same as others boot option.
> 
> Thanks
> Walon
> 
> -----Original Message-----
> From: gaoliming <gaoliming@byosoft.com.cn> 
> Sent: Friday, February 19, 2021 8:59 AM
> To: devel@edk2.groups.io; Li, Walon <walon.li@hpe.com>
> Cc: Wang, Sunny (HPS SW) <sunnywang@hpe.com>; lersek@redhat.com; ray.ni@intel.com; hao.a.wu@intel.com
> Subject: 回复: [edk2-devel] [PATCH] MdeModulePkg/UefiBootManagerLib: Put BootMenu at the end of BootOrder
> 
> Walon:
>   Can you specify the detail reason why BootManagerMenu should be placed at end of BootOrder?

In addition to Walon's answer, I'd like to point out that the current
code doesn't seem to explain why BootManagerMenu was ever placed at the
front.

Of course when we change code, the burden of justification is on the
patch that's being proposed; so I agree with the question.

However, answering that question is easier if the pre-patch code has an
explicit explanation, and that explanation can be shown to be wrong (or
at least to have missed a corner case or similar). If the pre-patch code
is undocumented, then arguing for the new code is more difficult.

Laszlo