From mboxrd@z Thu Jan 1 00:00:00 1970 From: robherring2@gmail.com (Rob Herring) Date: Thu, 13 Sep 2012 16:02:49 -0500 Subject: [PATCH] of: specify initrd location using 64-bit In-Reply-To: <5051816A.3050705@linutronix.de> References: <1347465937-7056-1-git-send-email-cyril@ti.com> <5050CE33.9060909@ti.com> <5050E965.5080405@linutronix.de> <505107DF.5020105@gmail.com> <5051816A.3050705@linutronix.de> Message-ID: <505249F9.7050201@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 09/13/2012 01:47 AM, Sebastian Andrzej Siewior wrote: > On 09/13/2012 12:08 AM, Rob Herring wrote: >>> Geert is right here. If it is a physical address, it should be >>> phys_addr_t. >> >> While generally true, for the DT specific code I think it should be a >> fixed u64. The size of the address is defined by the FDT, not the >> kernel. It is very likely we could have a FDT that specifies addresses >> in 64-bit values, but then we boot a kernel is compiled for !LPAE. >> phys_addr_t is currently sized based on LPAE setting. > > If your kernel is 32bit without PAE and your DTB address is >32ibt than > you can't handle it. If you don't notice this in your dt code than you > remap the wrong memory ioremap(). The size of the initrd fields are set by #address-cells properties and determined when you create the dtb. The address to load the initrd is decided by the bootloader/user and set at that point later in time. The dtb should not be tied to the kernel you are booting. Obviously, if you want to boot a non-PAE kernel, everything has to be placed at <4GB. I can boot i386 and i386-pae kernels on an i386-pae machines. I expect to generally be able to do that on ARM. Perhaps some SOCs like this one will not allow that, it is not always true. Rob