Re: [Qemu-devel] [Bug 1180923] [NEW] unused memory filled with 0x00 instead of 0xFF

[Stefan Hajnoczi]

On Thu, May 16, 2013 at 9:20 PM, Paolo Bonzini <address@hidden> wrote:
> Il 16/05/2013 19:34, TC1988 ha scritto:
>> Public bug reported:
>>
>> Qemu, ever since it was made (so, since 2003), has this problem in DOS
>> (either PC-DOS or MS-DOS and partly Windows 9x) not recognizing the
>> memory available when the memory is filled with 0x00 but when it is
>> filled with 0xFF it gets recognized properly, where should I patch qemu
>> to solve this memory problem?
>
> Can you provide reproduction instructions for this bug?

Sounds like (risky) memory probing.  On a PC the memory regions that
are unpopulated produce 0xff.

But you're supposed to use e820 or other mechanisms to retrieve the
proper memory layout from the firmware.

Stefan