> This is just to export a fixed log to userspace (like a DMI table) or > the kernel will actually use the data in some way? Based on the link, > it looks like the former to me. I could imagine both. The link is an in-kernel driver that exposes a log through a sysfs node (in a way that has already been established on x86 systems, which find the location through EBDA or ACPI entries instead). We are also using a user-space tool that reads the address from /proc/device-tree and accesses it through /dev/mem. The areas can contain many interesting entries (like the location of an early framebuffer set up by the firmware), so I could also imagine use cases where the kernel makes use of it directly. > Don't you need need to keep the kernel from allocating this memory by > using one of the reserved memory mechanisms? The recently added one > should be able to specific what the memory is reserved for IIRC. Our bootloader is carving the location out of the /memory node and adding it to the device tree reserve map. As far as I know, that only contains a list of raw start and size entries. At any rate, I think it's useful (and in line with other bindings) to add a more explicit node like this (if only to make it easier accessible through /proc/device-tree). > /firmware is already used IIRC. What if you have other firmware such > as Trustzone? I'm not quite sure how Trusted Foundations works and whether it would even make sense to use it in parallel to coreboot, but it seems to be using the /firmware/trusted-foundations subnode so that should be fine. "firmware" seems to be used by other firmware implementations (like "samsung,secure-firmware") which are similar in nature to and mutually exclusive with coreboot, so I thought the node makes sense. (The kernel should use the compatible string to find it anyway, so a future name clash would not be world-ending.) -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
