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UBoot SRAM - memory allocation

Posted: Wed Jul 17, 2019 10:15 am
by des2017
Hi,

I am trying to get UBoot running solely from SRAM without using the external DRAM on the SAMA5D2 xplained boards.

I have a requirement to check the DRAM ran using the mtest feature which has been enabled.

Currently ive slimmed UBoot < 64Kb and it executes as required post AT91bootstrap.

Ive found that UBoot utilises a region of memory in DRAM for HEAP/ TBL data, (checked using the bdinfo cmd)

Is there a flag / mode that disables Uboot allocating memory in DRAM?

Hoping someone can help.

Kind regards

Des

Re: UBoot SRAM - memory allocation

Posted: Thu Jul 18, 2019 1:00 am
by blue_z
des2017 wrote: I am trying to get UBoot running solely from SRAM without using the external DRAM on the SAMA5D2 xplained boards.

I have a requirement to check the DRAM ran using the mtest feature which has been enabled.
IMO that is an unusual and elaborate method to met a rather simple requirement.

des2017 wrote: Ive found that UBoot utilises a region of memory in DRAM for HEAP/ TBL data, (checked using the bdinfo cmd)

Is there a flag / mode that disables Uboot allocating memory in DRAM?
All the available configuration options should be documented in the README file of whatever version of U-Boot that you're using.
There is also more to study in the doc/ subdirectory.
I suspect you will have to hack the U-Boot initialization code besides enabling a few configuration options.

Regards

Re: UBoot SRAM - memory allocation

Posted: Thu Aug 01, 2019 11:10 am
by des2017
..look out for CONFIG_SYS_DRAM_TEST

The hook will allow tests to execute before Uboot allocates HEAP etc to DRAM.