Messages in this thread | | | Date | Sat, 12 Jun 2010 17:16:27 -0700 | From | "H. Peter Anvin" <> | Subject | Re: Bug#584846: Detects only 64MB and fails to boot on Intel Green City board if e820 hooked by GRUB2 |
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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.
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