What is 'new-res Mmio_ram(0x80000, 0 )' in '.io' file ?

Martin Schröder martin.schroeder at openlimit.com
Wed May 7 17:01:49 CEST 2014


Am 07.05.2014 12:22, schrieb Taeung:

> What mean 'DMAMEM' ?

The ethernet part of the i.MX reads/writes directly the received/sent 
Ethernet frames into/from RAM. So I need to alloc some space where the 
buffers are stored.

> And What is the function of which name is 'Mmio_ram()' ?

The CPU needs uncached access to this RAM so that the driver sees the 
received bytes (and not the values from the cache).

See also: <20110510162658.GG4941 at os.inf.tu-dresden.de>
Am 10.05.2011 18:26, schrieb Adam Lackorzynski:> Hi,
[...]
 > 'io' has the feature to get uncached memory, defining a resource
 > Mmio_ram(size_in_bytes, 1_for_superpages_0_otherwise) in the
 > configuration. That's the official way of getting uncached memory.


Martin






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