Re: Chainloading an MS Windows installer DVD

[Philip Couling]

Hopefully it should not matter what the media is. It's a USB, but I've
confirmed that grub is reading from it : I can "ls" the files on it and
find the EFI binary that way.

I guess I'm looking for a little more info on what chainloader does. My
firmware cannot read the image; I believe that is because of the UDF
filesystem. However grub can. I'm a little unclear on whether the
chainloader somehow asks the firmware to load the EFI binary or runs it
itself. Otherwise I don't know why grub can see this file (ls the file) but
not run it.

On Thu, 19 Oct 2023 at 16:55, Randy Goldenberg <randy.goldenberg@gmail.com>
wrote:

> According to the link you provided, the ISO file can be used to
> create installation media using a USB flash drive or DVD.  In the "subject"
> field of your email you refer to "MS Windows installer DVD", but in the
> body of your message you refer to "MS Windows Installer (on USB)".
>
> Please clarify what your boot media is, and describe how you created it.
>
> On Thu, Oct 19, 2023 at 2:36 AM Philip Couling <couling@gmail.com> wrote:
>
>> Hi
>>
>> Is there any reason why I can't chainload an MS Windows Installer (on
>> USB)?  Currently when I try this I get "UnknownError" when I type "boot"
>> at
>> the grub command line.
>>
>> The MS Windows ISOs are a bit weird: found here:
>> https://www.microsoft.com/en-gb/software-download/windows10ISO
>>
>> They are not partitioned and have a UDF filesystem instead of ISO 9660 or
>> FAT32. So my hardware cannot directly boot this.  But I was assuming that
>> all I would need to do would be ask grub to chainload the ISO as it has a
>> UDF driver.
>>
>> I can read the Windows Boot media after I "insmod udf" and then
>> "chainloader /efi/boot/bootx64.efi" which results in the output
>> "/EndEntire".  But when I then type "boot" I get "UnknownError".
>>
>> Has anyone experienced this? Any ideas about what isn't working? I freely
>> admit it could be a Microsoft weirdness that requires their input, I just
>> wanted to exhaust options here first.
>>
>> Thanks
>>
>