The x86 version is basically just a specialization of the base IO port version of the QEMU firmware configuration device, with the port addresses set for x86. The E820 entry type is x86 specific, and is a way to pass an E820 memory map to firmware which doesn't have another way to figure out where memory is. This would be for firmware like SeaBIOS which is itself responsible for publishing an E820 map, but it needs somewhere to get that information from in the first place. This mechanism is one it supports natively. This entry type reuses the E820Entry SimObjects which were defined a long time ago for passing to a Linux FS workload. It doesn't use their ability to write themselves out to guest memory, and just uses them as a transport for their address, size and type properties. Change-Id: Ifff214f5fc10bd7d0a2a0acddad4fc00dd65f67d Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/55628 Tested-by: kokoro <noreply+kokoro@google.com> Reviewed-by: Gabe Black <gabe.black@gmail.com> Maintainer: Gabe Black <gabe.black@gmail.com>
3.1 KiB
3.1 KiB