reserved memory from devicetree definition
Hi! Is there any way to use a reserved memory definition in the device tree to avoid that u-boot could use that SDRAM memory region? Or the only way is by compiler configuration?
Thanks
On Fri, Mar 5, 2021 at 8:26 AM jorge courett jorge.courett@gmail.com wrote:
Hi! Is there any way to use a reserved memory definition in the device tree to avoid that u-boot could use that SDRAM memory region? Or the only way is by compiler configuration?
The use case you pointed out is not supported by U-Boot. U-Boot currently only supports insert /reserved-memory node on some boards.
Patches are welcome to support the new use case :)
Regards, Bin
On 3/4/21 8:04 PM, Bin Meng wrote:
On Fri, Mar 5, 2021 at 8:26 AM jorge courett jorge.courett@gmail.com wrote:
Hi! Is there any way to use a reserved memory definition in the device tree to avoid that u-boot could use that SDRAM memory region? Or the only way is by compiler configuration?
The use case you pointed out is not supported by U-Boot. U-Boot currently only supports insert /reserved-memory node on some boards.
Patches are welcome to support the new use case :)
Regards, Bin
In the general case you can do this if your arch/board's dram_init calls fdtdec_setup_mem_size_base. Though there are numerous ways to override these values, so see setup_dest_addr for details. Do note that many memory addresses are set via several different methods, depending on the board. So you might need to have some compile-time modification anyway.
--Sean
Thanks Ben and Sean!!
I was trying to reserve the first 512K DDR memory, so due to uBoot relocation at the end of the DRR, it can be a guarantee that uBoot does not overlap to this section (2 G mem). For Linux, I am already using memory reserved node as described in https://www.kernel.org/doc/Documentation/devicetree/bindings/reserved-memory...
Indeed It could be better in uBoot if It could use the same devicetree configuration. As you say, implementing/changing the dram_init into the board.
Thanks again !!! Regards Jorge
On Thu, Mar 4, 2021 at 11:01 PM Sean Anderson seanga2@gmail.com wrote:
On 3/4/21 8:04 PM, Bin Meng wrote:
On Fri, Mar 5, 2021 at 8:26 AM jorge courett jorge.courett@gmail.com
wrote:
Hi! Is there any way to use a reserved memory definition in the device tree
to
avoid that u-boot could use that SDRAM memory region? Or the only way
is by
compiler configuration?
The use case you pointed out is not supported by U-Boot. U-Boot currently only supports insert /reserved-memory node on some boards.
Patches are welcome to support the new use case :)
Regards, Bin
In the general case you can do this if your arch/board's dram_init calls fdtdec_setup_mem_size_base. Though there are numerous ways to override these values, so see setup_dest_addr for details. Do note that many memory addresses are set via several different methods, depending on the board. So you might need to have some compile-time modification anyway.
--Sean
participants (3)
-
Bin Meng -
jorge courett -
Sean Anderson