From: "H. Peter Anvin" <hpa@zytor.com>
To: Josh Triplett <josh@joshtriplett.org>
Cc: Ben Hutchings <ben@decadent.org.uk>,
x86@kernel.org, 584846@bugs.debian.org,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: Bug#584846: Detects only 64MB and fails to boot on Intel Green City board if e820 hooked by GRUB2
Date: Sat, 12 Jun 2010 17:16:27 -0700 [thread overview]
Message-ID: <4C14235B.7030605@zytor.com> (raw)
In-Reply-To: <20100613000742.GA3469@feather>
On 06/12/2010 05:07 PM, Josh Triplett wrote:
> On Sat, Jun 12, 2010 at 04:02:44PM -0700, H. Peter Anvin wrote:
>> On 06/12/2010 03:26 PM, Josh Triplett wrote:
>>>
>>> Everything looks identical except for the region GRUB hooked right below
>>> the first reserved region; the unhooked version has available memory
>>> from 0-0x9cbf0, and the hooked version has available memory from
>>> 0-0x9cba0, then reserved from 0x9cba0-0x9cbec, then 4 bytes of available
>>> memory, and then the same reserved region as before.
>>
>> Actually... are both these done by chainloading Grub (with and without
>> mapping), or is the unhooked done without chainloading Grub at all?
>>
>> To me it looks like something is chaining INT 15h even in the
>> "unchained" case...
>
> The "unhooked" case still chainloaded from GRUB, just without calling
> drivemap and thus without hooking anything. I can test without
> chainloading from GRUB, though to the best of my knowledge GRUB doesn't
> hook int 15 unless it needs to intercept e820 (and e801 and 88).
>
> - Josh Triplett
Well *something* is... and it might not be Grub but one of the expansion
ROMs. If so, the problem is probably Grub stepping on the expansion ROM
by not honoring FBM.
-hpa
--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.
next prev parent reply other threads:[~2010-06-13 0:16 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20100612060322.29053.94187.reportbug@feather>
2010-06-12 13:58 ` Bug#584846: Detects only 64MB and fails to boot on Intel Green City board if e820 hooked by GRUB2 Ben Hutchings
2010-06-12 18:28 ` H. Peter Anvin
2010-06-12 18:55 ` Josh Triplett
2010-06-12 20:41 ` H. Peter Anvin
2010-06-12 21:45 ` Josh Triplett
[not found] ` <20100612222634.GA1785@feather>
2010-06-12 23:01 ` H. Peter Anvin
2010-06-12 23:02 ` H. Peter Anvin
2010-06-13 0:07 ` Josh Triplett
2010-06-13 0:16 ` H. Peter Anvin [this message]
[not found] ` <20100622052236.GA9130@feather>
2010-06-22 6:07 ` H. Peter Anvin
2010-06-22 16:07 ` Josh Triplett
2010-06-24 7:27 ` Josh Triplett
2010-06-24 14:18 ` H. Peter Anvin
2010-06-24 19:01 ` Josh Triplett
2010-06-24 20:58 ` H. Peter Anvin
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