xen, raspi4, linux-yocto-dev: Enable Xen on Raspberry Pi 4

Enable linux-yocto-dev as the Linux kernel for Xen on the
Raspberry Pi 4, with the bcm-2xxx-rpi4 KMACHINE and KBRANCH.

Set a Raspberry Pi SD card variable to increase the size of the boot
partition to accommodate both the kernel and the Xen hypervisor.

Signed-off-by: Christopher Clark <christopher.w.clark@gmail.com>
Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>

2 files changed, 14 insertions, 0 deletions

diff --git a/conf/distro/include/meta-virt-xen.inc b/conf/distro/include/meta-virt-xen.inc
index 0a91ef9a..44853d95 100644
--- a/conf/distro/include/meta-virt-xen.inc
+++ b/conf/distro/include/meta-virt-xen.inc
@@ -17,3 +17,7 @@ RPI_SDIMG_EXTRA_DEPENDS_append_raspberrypi4-64 = " xen:do_deploy"
 DEPLOYPAYLOAD_raspberrypi4-64 = "xen-${MACHINE}:xen"
 # We need the GIC enabled for Xen to work
 RPI_EXTRA_CONFIG_append_raspberrypi4-64  = "\nenable_gic=1"
+# Increase boot partition for space for kernel and Xen
+BOOT_SPACE_raspberrypi4-64 = "61440"
+# Override the meta-raspberrypi default kernel preference
+PREFERRED_PROVIDER_virtual/kernel_raspberrypi4-64 = "linux-yocto-dev"
diff --git a/dynamic-layers/raspberrypi/recipes-kernel/linux/linux-yocto-dev.bbappend b/dynamic-layers/raspberrypi/recipes-kernel/linux/linux-yocto-dev.bbappend
new file mode 100644
index 00000000..85d6febe
--- /dev/null
+++ b/dynamic-layers/raspberrypi/recipes-kernel/linux/linux-yocto-dev.bbappend
@@ -0,0 +1,10 @@
+# For a Xen-enabled distro on the Raspberry Pi, override the contents of cmdline.txt
+# with Xen-on-ARM-specific command line options
+
+DEFAULT_CMDLINE := "${CMDLINE}"
+XEN_LINUX_CMDLINE ?= "console=hvc0 clk_ignore_unused earlycon=xenboot debug root=/dev/mmcblk0p2 rootwait"
+CMDLINE = "${@bb.utils.contains('DISTRO_FEATURES', 'xen', '${XEN_LINUX_CMDLINE}', '${DEFAULT_CMDLINE}', d)}"
+
+KBRANCH_raspberrypi4-64 = "standard/bcm-2xxx-rpi"
+KMACHINE_raspberrypi4-64 = "bcm-2xxx-rpi4"
+COMPATIBLE_MACHINE_raspberrypi4-64 = "(raspberrypi4-64)"