[ipxe-devel] wimboot issue with server 2012 on physical servers

Michael Brown mcb30 at ipxe.org
Sat May 17 22:01:13 UTC 2014

On 16/05/14 14:55, Michael Brown wrote:
> On 15/05/14 15:12, Amit Shah wrote:
>> I had contacted you regarding an iPXE issue with Windows 8 (below). I
>> see a lot more people complain about this. There is a tool called Razor
>> by puppet labs. This uses iPXE and people trying this out are facing
>> this issue.
>> Is there any way to escalate this ? Is it possible for you guys to take
>> another look into this and find a possible solution.
> I had a thought about this the other day.
> The blank screen problem derives from a bug in bootmgr.exe: it will
> switch to graphical mode as soon as it determines that it can drive the
> VESA framebuffer display.  If it later finds that it doesn't have the
> fonts to display an error message, it will revert to plain text output.
>   However, it _fails_ to reconfigure the display for text output, with
> the result that the output is invisible.
> It occurred to me that there is a workaround for this.  All real-mode
> calls made by bootmgr.exe go through wimboot (which is how wimboot works
> in the first place; it intercepts INT 13 and emulates a FAT32 disk).  We
> could intercept the VESA BIOS calls and pretend that the system does not
> have a VESA framebuffer.  This should cause bootmgr.exe to remain in
> text mode, which would then ensure that error messages would be visible
> without requiring any font files.

I have implemented this in the latest version of wimboot (v1.0.5).  I 
have verified that an error messages which would previously be invisible 
due to missing fonts is now displayed in text mode.

Please retry with wimboot version 1.0.5.


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