Merge 4.16

Change-Id: I11db70a8e25a6656c5ec640a703e7b06d5a3672e

Documentation/mainboard/emulation/qemu-power9.md

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+# QEMU PPC64 emulator
+This page describes how to build and run coreboot for QEMU/PPC64.
+
+## Building coreboot
+```bash
+make defconfig KBUILD_DEFCONFIG=configs/config.emulation_qemu_power9
+make
+```
+
+This builds coreboot with no payload.
+
+## Payloads
+You can configure ELF or `skiboot` payload via `make menuconfig`. In either case
+you might need to adjust "ROM chip size" and make it large enough to accommodate
+the payload (see how much space it needs in the error you get if it doesn't
+fit).
+
+## Running coreboot in QEMU
+```bash
+qemu-system-ppc64 -M powernv,hb-mode=on \
+                  -cpu power9 \
+                  -bios build/coreboot.rom \
+                  -drive file=build/coreboot.rom,if=mtd \
+                  -serial stdio \
+                  -display none
+```
+
+- The default CPU in QEMU for AArch64 is a 604. You specify a suitable
+PowerPC CPU via `-cpu power9`.
+- By default Hostboot mode is off and needs to be turned on to run coreboot
+as a firmware rather than like an OS.
+- `-bios` specifies initial program (bootloader should suffice, but whole image
+works fine too).
+- `-drive` specifies image for emulated flash device.
+
+## Running with a kernel
+Loading `skiboot` (built automatically by coreboot or otherwise) allows
+specifying kernel and root file system to be run.
+
+```bash
+qemu-system-ppc64 -M powernv,hb-mode=on \
+                  -cpu power9 \
+                  -bios build/coreboot.rom \
+                  -drive file=build/coreboot.rom,if=mtd \
+                  -serial stdio \
+                  -display none \
+                  -kernel zImage \
+                  -initrd initrd.cpio.xz
+```
+
+- Specify path to your kernel via `-kernel`.
+- Specify path to your rootfs via `-initrd`.