baremetal-helloworld: Enable RISC-V 64 port

Add support for MACHINE=qemuriscv64.

$ runqemu nographic

KERNEL: [tmp/deploy/images/qemuriscv64/baremetal-helloworld-image-qemuriscv64.bin]
MACHINE: [qemuriscv64]
FSTYPE: [bin]

runqemu - INFO - Running tmp/work/x86_64-linux/qemu-helper-native/1.0-r1/recipe-sysroot-native/usr/bin/qemu-system-riscv64

Hello OpenEmbedded on RISC-V 64!

(From OE-Core rev: 31fde82640bf0d185eab55d2cbaf663c9faae801)

Signed-off-by: Alejandro Enedino Hernandez Samaniego <alejandro@enedino.org>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta-skeleton/recipes-baremetal/baremetal-examples/baremetal-helloworld_git.bb

@@ -4,7 +4,7 @@ DESCRIPTION = "These are introductory examples to showcase the use of QEMU to ru
 LICENSE = "MIT"
 LIC_FILES_CHKSUM = "file://LICENSE;md5=39346640a23c701e4f459e05f56f4449"
 
-SRCREV = "99f4fa4a3b266b42b52af302610b0f4f429ba5e3"
+SRCREV = "0bf9ea216e6f76be50726a3a74e527b7bbb0ad93"
 PV = "0.1+git${SRCPV}"
 
 SRC_URI = "git://github.com/aehs29/baremetal-helloqemu.git;protocol=https;branch=master"
@@ -28,12 +28,13 @@ inherit baremetal-image
 # machine that QEMU uses on OE, e.g. -machine virt -cpu cortex-a57
 # but the examples can also be run on other architectures/machines
 # such as vexpress-a15 by overriding the setting on the machine.conf
-COMPATIBLE_MACHINE = "qemuarmv5|qemuarm|qemuarm64"
+COMPATIBLE_MACHINE = "qemuarmv5|qemuarm|qemuarm64|qemuriscv64"
 
 BAREMETAL_QEMUARCH ?= ""
 BAREMETAL_QEMUARCH_qemuarmv5 = "versatile"
 BAREMETAL_QEMUARCH_qemuarm = "arm"
 BAREMETAL_QEMUARCH_qemuarm64 = "aarch64"
+BAREMETAL_QEMUARCH_qemuriscv64 = "riscv64"
 
 EXTRA_OEMAKE_append = " QEMUARCH=${BAREMETAL_QEMUARCH} V=1"
 

meta/classes/baremetal-image.bbclass

@@ -73,7 +73,19 @@ QB_DEFAULT_KERNEL ?= "${IMAGE_LINK_NAME}.bin"
 QB_MEM ?= "-m 256"
 QB_DEFAULT_FSTYPE ?= "bin"
 QB_DTB ?= ""
-QB_OPT_APPEND = "-nographic"
+QB_OPT_APPEND_append = " -nographic"
+
+# RISC-V tunes set the BIOS, unset, and instruct QEMU to
+# ignore the BIOS and boot from -kernel
+QB_DEFAULT_BIOS_qemuriscv64 = ""
+QB_OPT_APPEND_append_qemuriscv64 = " -bios none"
+
+
+# Use the medium-any code model for the RISC-V 64 bit implementation,
+# since medlow can only access addresses below 0x80000000 and RAM
+# starts at 0x80000000 on RISC-V 64
+CFLAGS_append_qemuriscv64 = " -mcmodel=medany"
+
 
 # This next part is necessary to trick the build system into thinking
 # its building an image recipe so it generates the qemuboot.conf