Reserving physical memory in Linux
Hi, I want to reserve one range of physical memory say from 0x10000000 of 256MB in Linux. This region is required for DMA functions alone. Please help me understand how we can reserve this in Linux. Can this be done using boot options or any other? Regards, Asha
look at alloc_bootmem and family of function to allocate memory at boot time, description for same is available in chapter 8 Linux device drivers. Rajat On Mon, Dec 27, 2010 at 12:29 PM, Asha R <rd.asha22@gmail.com> wrote:
Hi, I want to reserve one range of physical memory say from 0x10000000 of 256MB in Linux. This region is required for DMA functions alone. Please help me understand how we can reserve this in Linux. Can this be done using boot options or any other?
Regards, Asha _______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
On Mon, Dec 27, 2010 at 2:59 PM, Asha R <rd.asha22@gmail.com> wrote:
Hi, I want to reserve one range of physical memory say from 0x10000000 of 256MB in Linux. This region is required for DMA functions alone. Please help me understand how we can reserve this in Linux. Can this be done using boot options or any other?
Regards, Asha
try adding "mem=256M$0x10000000" in arg. via http://lxr.linux.no/source/Documentation/kernel-parameters.txt -- Regards, Adam Lee -------------------------------------------------- E-mail: adam8157@gmail.com Website: http://www.adam8157.info --------------------------------------------------
Thanks Adam Lee. Is this mem= or memmap=? Regards, Asha On Mon, Dec 27, 2010 at 1:01 PM, Adam Lee <adam8157@gmail.com> wrote:
On Mon, Dec 27, 2010 at 2:59 PM, Asha R <rd.asha22@gmail.com> wrote:
Hi, I want to reserve one range of physical memory say from 0x10000000 of 256MB in Linux. This region is required for DMA functions alone. Please help me understand how we can reserve this in Linux. Can this be done using boot options or any other?
Regards, Asha
try adding "mem=256M$0x10000000" in arg.
via http://lxr.linux.no/source/Documentation/kernel-parameters.txt
-- Regards, Adam Lee -------------------------------------------------- E-mail: adam8157@gmail.com Website: http://www.adam8157.info --------------------------------------------------
Asha, You let the kernel now that X amount is DMA space only. It depends on architecture though. What is architecture being worked upon? - Bharath H S On Mon, Dec 27, 2010 at 2:36 PM, Asha R <rd.asha22@gmail.com> wrote:
Thanks Adam Lee. Is this mem= or memmap=? Regards, Asha On Mon, Dec 27, 2010 at 1:01 PM, Adam Lee <adam8157@gmail.com> wrote:
On Mon, Dec 27, 2010 at 2:59 PM, Asha R <rd.asha22@gmail.com> wrote:
Hi, I want to reserve one range of physical memory say from 0x10000000 of 256MB in Linux. This region is required for DMA functions alone. Please help me understand how we can reserve this in Linux. Can this be done using boot options or any other?
Regards, Asha
try adding "mem=256M$0x10000000" in arg.
via http://lxr.linux.no/source/Documentation/kernel-parameters.txt
-- Regards, Adam Lee -------------------------------------------------- E-mail: adam8157@gmail.com Website: http://www.adam8157.info --------------------------------------------------
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participants (4)
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Adam Lee -
Asha R -
Bharath H S -
Rajat Sharma