Xilinx Versal Virt (``xlnx-versal-virt``)
=========================================
Xilinx Versal is a family of heterogeneous multi-core SoCs
(System on Chip) that combine traditional hardened CPUs and I/O
peripherals in a Processing System (PS) with runtime programmable
FPGA logic (PL) and an Artificial Intelligence Engine (AIE).
More details here:
https://www.xilinx.com/products/silicon-devices/acap/versal.html
The family of Versal SoCs share a single architecture but come in
different parts with different speed grades, amounts of PL and
other differences.
The Xilinx Versal Virt board in QEMU is a model of a virtual board
(does not exist in reality) with a virtual Versal SoC without I/O
limitations. Currently, we support the following cores and devices:
Implemented CPU cores:
- 2 ACPUs (ARM Cortex-A72)
Implemented devices:
- Interrupt controller (ARM GICv3)
- 2 UARTs (ARM PL011)
- An RTC (Versal built-in)
- 2 GEMs (Cadence MACB Ethernet MACs)
- 8 ADMA (Xilinx zDMA) channels
- 2 SD Controllers
- OCM (256KB of On Chip Memory)
- DDR memory
QEMU does not yet model any other devices, including the PL and the AI Engine.
Other differences between the hardware and the QEMU model:
- QEMU allows the amount of DDR memory provided to be specified with the
``-m`` argument. If a DTB is provided on the command line then QEMU will
edit it to include suitable entries describing the Versal DDR memory ranges.
- QEMU provides 8 virtio-mmio virtio transports; these start at
address ``0xa0000000`` and have IRQs from 111 and upwards.
Running
"""""""
If the user provides an Operating System to be loaded, we expect users
to use the ``-kernel`` command line option.
Users can load firmware or boot-loaders with the ``-device loader`` options.
When loading an OS, QEMU generates a DTB and selects an appropriate address
where it gets loaded. This DTB will be passed to the kernel in register x0.
If there's no ``-kernel`` option, we generate a DTB and place it at 0x1000
for boot-loaders or firmware to pick it up.
If users want to provide their own DTB, they can use the ``-dtb`` option.
These DTBs will have their memory nodes modified to match QEMU's
selected ram_size option before they get passed to the kernel or FW.
When loading an OS, we turn on QEMU's PSCI implementation with SMC
as the PSCI conduit. When there's no ``-kernel`` option, we assume the user
provides EL3 firmware to handle PSCI.
A few examples:
Direct Linux boot of a generic ARM64 upstream Linux kernel:
.. code-block:: bash
$ qemu-system-aarch64 -M xlnx-versal-virt -m 2G \
-serial mon:stdio -display none \
-kernel arch/arm64/boot/Image \
-nic user -nic user \
-device virtio-rng-device,bus=virtio-mmio-bus.0 \
-drive if=none,index=0,file=hd0.qcow2,id=hd0,snapshot \
-drive file=qemu_sd.qcow2,if=sd,index=0,snapshot \
-device virtio-blk-device,drive=hd0 -append root=/dev/vda
Direct Linux boot of PetaLinux 2019.2:
.. code-block:: bash
$ qemu-system-aarch64 -M xlnx-versal-virt -m 2G \
-serial mon:stdio -display none \
-kernel petalinux-v2019.2/Image \
-append "rdinit=/sbin/init console=ttyAMA0,115200n8 earlycon=pl011,mmio,0xFF000000,115200n8" \
-net nic,model=cadence_gem,netdev=net0 -netdev user,id=net0 \
-device virtio-rng-device,bus=virtio-mmio-bus.0,rng=rng0 \
-object rng-random,filename=/dev/urandom,id=rng0
Boot PetaLinux 2019.2 via ARM Trusted Firmware (2018.3 because the 2019.2
version of ATF tries to configure the CCI which we don't model) and U-boot:
.. code-block:: bash
$ qemu-system-aarch64 -M xlnx-versal-virt -m 2G \
-serial stdio -display none \
-device loader,file=petalinux-v2018.3/bl31.elf,cpu-num=0 \
-device loader,file=petalinux-v2019.2/u-boot.elf \
-device loader,addr=0x20000000,file=petalinux-v2019.2/Image \
-nic user -nic user \
-device virtio-rng-device,bus=virtio-mmio-bus.0,rng=rng0 \
-object rng-random,filename=/dev/urandom,id=rng0
Run the following at the U-Boot prompt:
.. code-block:: bash
Versal>
fdt addr $fdtcontroladdr
fdt move $fdtcontroladdr 0x40000000
fdt set /timer clock-frequency <0x3dfd240>
setenv bootargs "rdinit=/sbin/init maxcpus=1 console=ttyAMA0,115200n8 earlycon=pl011,mmio,0xFF000000,115200n8"
booti 20000000 - 40000000
fdt addr $fdtcontroladdr
Boot Linux as DOM0 on Xen via U-Boot:
.. code-block:: bash
$ qemu-system-aarch64 -M xlnx-versal-virt -m 4G \
-serial stdio -display none \
-device loader,file=petalinux-v2019.2/u-boot.elf,cpu-num=0 \
-device loader,addr=0x30000000,file=linux/2018-04-24/xen \
-device loader,addr=0x40000000,file=petalinux-v2019.2/Image \
-nic user -nic user \
-device virtio-rng-device,bus=virtio-mmio-bus.0,rng=rng0 \
-object rng-random,filename=/dev/urandom,id=rng0
Run the following at the U-Boot prompt:
.. code-block:: bash
Versal>
fdt addr $fdtcontroladdr
fdt move $fdtcontroladdr 0x20000000
fdt set /timer clock-frequency <0x3dfd240>
fdt set /chosen xen,xen-bootargs "console=dtuart dtuart=/uart@ff000000 dom0_mem=640M bootscrub=0 maxcpus=1 timer_slop=0"
fdt set /chosen xen,dom0-bootargs "rdinit=/sbin/init clk_ignore_unused console=hvc0 maxcpus=1"
fdt mknode /chosen dom0
fdt set /chosen/dom0 compatible "xen,multiboot-module"
fdt set /chosen/dom0 reg <0x00000000 0x40000000 0x0 0x03100000>
booti 30000000 - 20000000
Boot Linux as Dom0 on Xen via ARM Trusted Firmware and U-Boot:
.. code-block:: bash
$ qemu-system-aarch64 -M xlnx-versal-virt -m 4G \
-serial stdio -display none \
-device loader,file=petalinux-v2018.3/bl31.elf,cpu-num=0 \
-device loader,file=petalinux-v2019.2/u-boot.elf \
-device loader,addr=0x30000000,file=linux/2018-04-24/xen \
-device loader,addr=0x40000000,file=petalinux-v2019.2/Image \
-nic user -nic user \
-device virtio-rng-device,bus=virtio-mmio-bus.0,rng=rng0 \
-object rng-random,filename=/dev/urandom,id=rng0
Run the following at the U-Boot prompt:
.. code-block:: bash
Versal>
fdt addr $fdtcontroladdr
fdt move $fdtcontroladdr 0x20000000
fdt set /timer clock-frequency <0x3dfd240>
fdt set /chosen xen,xen-bootargs "console=dtuart dtuart=/uart@ff000000 dom0_mem=640M bootscrub=0 maxcpus=1 timer_slop=0"
fdt set /chosen xen,dom0-bootargs "rdinit=/sbin/init clk_ignore_unused console=hvc0 maxcpus=1"
fdt mknode /chosen dom0
fdt set /chosen/dom0 compatible "xen,multiboot-module"
fdt set /chosen/dom0 reg <0x00000000 0x40000000 0x0 0x03100000>
booti 30000000 - 20000000
