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Subject: Re: [syslinux] Using memdisk with grub2 and a gzip-compressed ISO
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On 04/23/2015 08:14 PM, Andrei Borzenkov wrote:
> =D0=92 Thu, 23 Apr 2015 15:17:02 -0700
> "H. Peter Anvin" <hpa@zytor.com> =D0=BF=D0=B8=D1=88=D0=B5=D1=82:
>=20
>> On 04/23/2015 07:23 AM, David Shaw via Syslinux wrote:
>>>
>>> I'm not sure if this is related to the problem, but note the length
>>> in the "Ramdisk" line from grub legacy is one byte shorter than the
>>> length from grub2.  Also note that the length given in the "gzip
>>> image" line is shifted one byte to the left in the grub legacy
>>> version (i.e. it's exactly 0x100 times larger).
>>>
>>
>> That would definitely break using a compressed ramdisk.
>=20
> It does not break for kernel. What makes is so different in case of
> syslinux?
>=20

Padding the image doesn't matter for the kernel, but memdisk relies on
being able to see where the end of the compressed image is, because that
is where the length is located.

	-hpa