bootlog/ Reserved memory

Forum about Parallella boot process, linux kernel, distros, SD-cards, etc.

bootlog/ Reserved memory

Postby tnt » Tue Jun 25, 2013 5:34 pm


Could someone pastebin a bootlog from their parallella with the original SD card image installed ?

During boot on mine I see messages like :

Code: Select all
cma: CMA: reserved 16 MiB at 1e800000
Memory: 512MB = 512MB total
Memory: 497612k/497612k available, 26676k reserved, 0K highmem

While AFAIK the aread 0x1e000000 -> 0x20000000 should be completely invisible to linux.

I also see this when using 'free'

Code: Select all
             total       used       free     shared    buffers     cached
Mem:           502         58        443          0          9         28
-/+ buffers/cache:         20        481
Swap:            0          0          0

So I'm suspecting somehow the reserved zone ... isn't really reserved.


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Re: bootlog/ Reserved memory

Postby rtrogan » Tue Jun 25, 2013 9:54 pm

Hi Sylvain,
You are absolutely right, the u-boot built with xilinx-v14.4 tag will boot Linux without reserving any memory (ignoring what is defined in the devicetree.dtb). This happens because bootm command verifies and alters devicetree.dtb before booting Linux. In the older versions of u-boot the boot was performed without bootm command and modifying the source code of devicetree only was sufficient for getting reserved memory area. Now, when booting with bootm command we have to make an additional changes to u-boot source code (sorry I forgot to update the user guide).

Please add the following line to u-boot-xlnx/include/configs/zynq_zed.h and build new u-boot:

#define CONFIG_SYS_MEM_TOP_HIDE 0x2000000

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