Dear Nobuhiro,
In message CABMQnV+k+Rmx7E8o-nfBpYg5-nWrXi6Oz_+BCYs-vDNdv_z-rw@mail.gmail.com you wrote:
Please explain why you would want to do this. To me it makes no sense. Either U-Boot knows the correct memory size, then it should pass it to Linux. Or it does not, then U-Boot should be fixed.
For example, I can access the memory of all in the U-Boot, but I may want to control the highmem on Linux,I do not want to show a specific area from kernel and userland.
Is it not sufficient to pass some "mem=" boot argument? We even have automatic support for this in U-Boot (see the CONFIG_PRAM feature).
Also, I object that your implementation is ARM specific. If such a feature gets added, it should be architecture independent.
I see. But arch_fixup_memory_node() is used by ARM only. So, we see to be dependent on the ARM is only this.
All architectures that support the device tree update the memory size for Linux, so we should find a generic way to handle this. Actually we should always strive to reduce this arhitecture specific code.
Best regards,
Wolfgang Denk