misc/emulation: Add x86 U-Boot and arm64 examples

Add an example qemu-system invocation for the qemu_x86_12mb board's
U-Boot payload. List the QEMU arm64 board in the supported hardware page
and an example invocation for that as well.

Signed-off-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>

site/docs/hardware/index.md

@@ -91,6 +91,7 @@ process makes use of coreboot's own cross-compile toolchain.
 ### Emulation
 
 -   [Qemu x86](../misc/emulation.md)
+-   [Qemu arm64](../misc/emulation.md)
 
 
 TODO: More hardware is supported. See `resources/coreboot/` in lbmk. Update

site/docs/misc/emulation.md

@@ -25,6 +25,15 @@ For example:
 
 `qemu-system-x86_64 -bios bin/qemu_x86_12mb/grub_qemu_x86_12mb_libgfxinit_corebootfb_usqwerty.rom`
 
+`qemu-system-x86_64 -bios bin/qemu_x86_12mb/uboot_payload_qemu_x86_12mb_libgfxinit_corebootfb.rom -serial stdio`
+
+There is basic support for an arm64 virtual machine as well, although the payloads are not as developed as the x86 one:
+
+    ./build boot roms qemu_arm64_12mb
+
+    qemu-system-aarch64 -bios bin/qemu_arm64_12mb/uboot_payload_qemu_arm64_12mb_libgfxinit_corebootfb.rom \
+        -M virt,secure=on,virtualization=on,acpi=on -cpu cortex-a53 -m 768M -serial stdio -vga none -display none
+
 Use Cases
 =========