[Trac #311] OF fails to load large (~6M) initrd
Zarro Boogs per Child
bugtracker at laptop.org
Tue Nov 7 17:32:49 EST 2006
#311: OF fails to load large (~6M) initrd
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Reporter: dwmw2 | Owner: wmb at firmworks.com
Type: defect | Status: assigned
Priority: normal | Milestone: BTest-2
Component: OFW | Resolution:
Keywords: |
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Changes (by wmb at firmworks.com):
* status: new => assigned
Comment:
The root cause of this problem is that OFW uses the area just below the 16
MB boundary for driver DMA (that address was chosen some time ago, based
on some old devices and chipsets that had only 24-bit DMA addressing).
When loading a large ramdisk image into the standard location at 8MB, the
loading and inflating process can end up encroaching into that DMA area.
One manifestation is image corruption, for example when the USB host
controller does DMA writes to its descriptor lists, thus overwriting parts
of the image.
The solution is to move the DMA allocation region somewhere else far out
of harm's way.
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Ticket URL: <http://dev.laptop.org/ticket/311#comment:1>
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