Xen ARM with Virtualization Extensions/OMAP5432 uEVM

The OMAP5432 uEVM board is now supported in Xen upstream.

1. Prepare U-boot

Xen hypervisor requires to be booted in HYP mode by the bootloader. Make sure that the U-boot you use would keep staying in HYP mode when switching the control to Xen.

2. Build Xen and Linux Dom0

2.1 Build Xen hypervisor

Build Xen:

# git clone git://xenbits.xen.org/xen.git
# cd xen
# make dist-xen XEN_TARGET_ARCH=arm32 CROSS_COMPILE=arm-linux-gnueabihf- CONFIG_EARLY_PRINTK=omap5432

Create uImage for Xen:

 # mkimage -A arm -T kernel -a 0x80200000 -e 0x80200000 -C none -d "xen/xen" xen-uImage

2.2 Build Linux Dom0 kernel

Get the linux kernel source from upstream:

 # git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

Use the default ‘omap2plus' as the base config:

# make omap2plus_defconfig ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf-

Before adding the XEN related kernel configs, disable old omap SoCs support by unselecting the TI OMAP2/3/4 in the ‘System Type’ section of kernel configuration menus (by running ‘make menuconfig ARCH=arm’).

Adding the following config entries in .config and run ‘make olddefconfig ARCH=arm’:

CONFIG_XEN_DOM0=y
CONFIG_XEN=y
CONFIG_XEN_BLKDEV_FRONTEND=y
CONFIG_XEN_BLKDEV_BACKEND=y
CONFIG_XEN_NETDEV_FRONTEND=y
CONFIG_XEN_NETDEV_BACKEND=y
CONFIG_INPUT_XEN_KBDDEV_FRONTEND=y
CONFIG_HVC_XEN=y
CONFIG_HVC_XEN_FRONTEND=y
CONFIG_XEN_DEV_EVTCHN=y
CONFIG_XEN_BACKEND=y
CONFIG_XENFS=y
CONFIG_XEN_COMPAT_XENFS=y
CONFIG_XEN_SYS_HYPERVISOR=y
CONFIG_XEN_XENBUS_FRONTEND=y
CONFIG_XEN_GNTDEV=y
CONFIG_XEN_GRANT_DEV_ALLOC=y
CONFIG_XEN_PRIVCMD=y

OMAP kernel still uses hwmod to describe its on-chip hardware blocks. Thus, we need to disable the UART3 used by Xen serial console by directly modifying the kernel source.

diff --git a/arch/arm/mach-omap2/omap_hwmod_54xx_data.c b/arch/arm/mach-omap2/omap_hwmod_54xx_data.c
index 8923172..29e2b68 100644
--- a/arch/arm/mach-omap2/omap_hwmod_54xx_data.c
+++ b/arch/arm/mach-omap2/omap_hwmod_54xx_data.c
@@ -2474,7 +2474,9 @@ static struct omap_hwmod_ocp_if *omap54xx_hwmod_ocp_ifs[] __initdata = {
        &omap54xx_l4_per__timer11,
        &omap54xx_l4_per__uart1,
        &omap54xx_l4_per__uart2,
+#if 0
        &omap54xx_l4_per__uart3,
+#endif
        &omap54xx_l4_per__uart4,
        &omap54xx_l4_per__uart5,
        &omap54xx_l4_per__uart6,

Build the kernel:

# make zImage ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf-

2.3 Build FDT

Apply the patch below to the upstream linux kernel and build the device tree blob.

commit 7d6802fe562710d296881d5d9aeb5cfeff76354f
Author: Chen Baozi <baozich@gmail.com>
Date:   Tue Apr 29 09:24:15 2014 +0800

    arm: dts: OMAP5: Add Xen support in DTS of OMAP5432 uEVM

diff --git a/arch/arm/boot/dts/omap5-uevm.dts b/arch/arm/boot/dts/omap5-uevm.dts
index 3b99ec2..18caa26 100644
--- a/arch/arm/boot/dts/omap5-uevm.dts
+++ b/arch/arm/boot/dts/omap5-uevm.dts
@@ -15,6 +15,27 @@
        model = "TI OMAP5 uEVM board";
        compatible = "ti,omap5-uevm", "ti,omap5";

+       chosen {
+               bootargs = "dom0_mem=256M console=dtuart dtuart=serial2 earlyprintk=xen";
+               xen,dom0-bootargs = "console=hvc0,115200n8 earlyprintk=xen debug ignore_loglevel root=/dev/mmcblk0p2 rw rootwait fixrtc";
+               modules {
+                       #address-cells = <1>;
+                       #size-cells = <1>;
+
+                       module@0 {
+                               compatible = "xen,linux-zimage", "xen,multiboot-module";
+                               reg = <0xa0000000 0xa00000>;
+                       };
+               };
+       };
+
+       psci {
+               compatible      = "arm,psci";
+               method          = "smc";
+               cpu_off         = <1>;
+               cpu_on          = <2>;
+       };
+
        memory {
                device_type = "memory";
                reg = <0x80000000 0x7F000000>; /* 2032 MB */
@@ -199,7 +220,7 @@
 };

 &mmc1 {
-       vmmc-supply = <&ldo9_reg>;
+       vmmc-supply = <&vmmcsd_fixed>;
        bus-width = <4>;
 };

diff --git a/arch/arm/boot/dts/omap5.dtsi b/arch/arm/boot/dts/omap5.dtsi
index f8c9855..dfc229c 100644
--- a/arch/arm/boot/dts/omap5.dtsi
+++ b/arch/arm/boot/dts/omap5.dtsi
@@ -80,6 +80,7 @@
                             <GIC_PPI 14 (GIC_CPU_MASK_RAW(3) | IRQ_TYPE_LEVEL_LOW)>,
                             <GIC_PPI 11 (GIC_CPU_MASK_RAW(3) | IRQ_TYPE_LEVEL_LOW)>,
                             <GIC_PPI 10 (GIC_CPU_MASK_RAW(3) | IRQ_TYPE_LEVEL_LOW)>;
+               clock-frequency = <6144000>;
        };

        gic: interrupt-controller@48211000 {
@@ -90,6 +91,7 @@
                      <0x48212000 0x1000>,
                      <0x48214000 0x2000>,
                      <0x48216000 0x2000>;
+               interrupts = <1 9 0xf04>;
        };

        /*

2.4 All together

Now we should have 3 files as following:

• xen-uImage
• zImage
• omap5-uevm.dtb

Then copy all these 3 files to the /boot partition of your MICRO-SD card.

3. Boot Xen and Dom0

Use the following U-boot command sequence to boot Xen & dom0:

OMAP5430 EVM # fatload mmc 0:1 0x825f0000 omap5-uevm.dtb
OMAP5430 EVM # fatload mmc 0:1 0x90000000 xen-uImage
OMAP5430 EVM # fatload mmc 0:1 0xa0000000 zImage
OMAP5430 EVM # bootm 0x90000000 - 0x825f0000