[GSoC] Defining Memory for MMU page tables at CSB337

[Hesham Moustafa]

I intended to dynamically allocate memory for it, but i thought it would be
faster to define an area for lvl2 page tables to access/allocate them
faster. I just want to be sure that CSB337 implement malloc. I noticed that
line at linker script for CSB337

HeapSize = 0;

that why i am inquiring about that issue.

thanks,
Hesham


On Sat, Aug 4, 2012 at 11:02 PM, Joel Sherrill <Joel.Sherrill at oarcorp.com>wrote:

> Does it have to be placed in the linker script?
>
> Can you dynamically allocate it as the properly needed size?
> ________________________________________
> From: rtems-devel-bounces at rtems.org [rtems-devel-bounces at rtems.org] On
> Behalf Of Hesham Moustafa [heshamelmatary at gmail.com]
> Sent: Saturday, August 04, 2012 7:52 AM
> To: rtems-devel at rtems.org
> Subject: [GSoC] Defining Memory for MMU page tables at CSB337
>
> Hi,
>
> I want to define memory for page tables at CSB337 BSP.
>
> The following is quoted from lincmds.csb337
>
> MEMORY {
> SDRAM_MMU : ORIGIN = 0x20100000, LENGTH = 16k
> SDRAM : ORIGIN = 0x20104000, LENGTH = 15M - 16k
> SRAM : ORIGIN = 0x00200000, LENGTH = 16k
> NIRVANA : ORIGIN = 0, LENGTH = 0
> }
>
> That only allocate page table for level 1 page table which is 16 k ( each
> entry represents 1M page of memory). I'd like to add level 2 page tables to
> represent 4k pages. A level-2 page table consists of 256 entry and consumes
> 1K of memory and its base address is installed at level-1 page table entry.
>
> The question is what's the proper size of level-2 page tables to reserve
> from memory and what should be its base address (ORIGIN) to be written at
> that linker script ?
>
> Thanks,
> Hesham
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.rtems.org/pipermail/devel/attachments/20120805/55625dd1/attachment-0001.html>