[coreboot] memtest86 reading 0k memory

Timothy Pearson tpearson at raptorengineeringinc.com
Thu Feb 5 19:48:25 CET 2015


On 02/05/2015 12:38 PM, Jonathan A. Kollasch wrote:
> That's a pretty old memtest86+.  Also, memtest86+ prefers
> linuxbios/coreboot memory map to e820.  This becomes a problem
> when SeaBIOS sets up a USB controller to DMA to e820-reserved
> memory that wasn't reserved by coreboot.
>
> Try a modern memtest86+ with the coreboot table probe patched out.
>
> 	Jonathan Kollasch

Yep, that was it.  Didn't catch the obsolete version number.

I'm trying to figure out the point of memtest86 reading the coreboot 
tables.  It doesn't help that the coreboot tables / e820 map are 
apparently wrong; memtest86+ almost immediately started stepping on the 
lower MMIO regions (e.g. 0xb800) rendering the display mostly useless. 
Interestingly Linux doesn't seem to have any problems; I'll need to 
investigate further.

-- 
Timothy Pearson
Raptor Engineering
+1 (415) 727-8645
http://www.raptorengineeringinc.com



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