What is 'new-res Mmio_ram(0x80000, 0 )' in '.io' file ?
Hi, l4 hackers :-) I'm trying to secure Ethernet on L4 linux using Freescale imx6q. Referencing other 'imx28.io' file which succeeded in securing Ethernet , I'm modifying my 'imx6q.io' file as follows.. =================== hw-root { NIC => new Deviceo() { .hi-d = "imx6q-fec"; new-res Mmio (0x02188000 .. 0x0218BFFF); new-res Irq (150); new-res Irq (151); } DMAMEM => new Deivce() { .hid ="dmamem"; new-res Mmio_ram (0x80000, 0); } 141x => new System_bus() { "imx6q-fec" -> wrap(hw-root.NIC); "dmamem" => wrap(hw-root, DMAMEM); ) } =================== What mean 'DMAMEM' ? And What is the function of which name is 'Mmio_ram()' ? I know that 'Mmio()' need arguments which are start and end address. But, I don't know 'Mmio_ram()'. Please, help me. If you tell a bit me hints, I'd appreciate it. - Taeung -
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@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
participants (2)
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Martin Schröder -
Taeung