.. SPDX-License-Identifier: GPL-2.0+ .. Copyright (C) 2017, Tuomas Tynkkynen QEMU ARM ======== QEMU for ARM supports a special 'virt' machine designed for emulation and virtualization purposes. This document describes how to run U-Boot under it. Both 32-bit ARM and AArch64 are supported. The 'virt' platform provides the following as the basic functionality: - A freely configurable amount of CPU cores - U-Boot loaded and executing in the emulated flash at address 0x0 - A generated device tree blob placed at the start of RAM - A freely configurable amount of RAM, described by the DTB - A PL011 serial port, discoverable via the DTB - An ARMv7/ARMv8 architected timer - PSCI for rebooting the system - A generic ECAM-based PCI host controller, discoverable via the DTB Additionally, a number of optional peripherals can be added to the PCI bus. See :doc:`../../develop/devicetree/dt_qemu` for information on how to see the devicetree actually generated by QEMU. Building U-Boot --------------- Set the CROSS_COMPILE environment variable as usual, and run: - For ARM:: make qemu_arm_defconfig make - For AArch64:: make qemu_arm64_defconfig make Running U-Boot -------------- The minimal QEMU command line to get U-Boot up and running is: - For ARM:: qemu-system-arm -machine virt -nographic -bios u-boot.bin - For AArch64:: qemu-system-aarch64 -machine virt -nographic -cpu cortex-a57 -bios u-boot.bin Note that for some odd reason qemu-system-aarch64 needs to be explicitly told to use a 64-bit CPU or it will boot in 32-bit mode. The -nographic argument ensures that output appears on the terminal. Use Ctrl-A X to quit. Additional persistent U-Boot environment support can be added as follows: - Create envstore.img using qemu-img:: qemu-img create -f raw envstore.img 64M - Add a pflash drive parameter to the command line:: -drive if=pflash,format=raw,index=1,file=envstore.img Additional peripherals that have been tested to work in both U-Boot and Linux can be enabled with the following command line parameters: - To add a Serial ATA disk via an Intel ICH9 AHCI controller, pass e.g.:: -drive if=none,file=disk.img,format=raw,id=mydisk \ -device ich9-ahci,id=ahci -device ide-drive,drive=mydisk,bus=ahci.0 - To add an Intel E1000 network adapter, pass e.g.:: -netdev user,id=net0 -device e1000,netdev=net0 - To add an EHCI-compliant USB host controller, pass e.g.:: -device usb-ehci,id=ehci - To add an NVMe disk, pass e.g.:: -drive if=none,file=disk.img,id=mydisk -device nvme,drive=mydisk,serial=foo - To add a random number generator, pass e.g.:: -device virtio-rng-pci These have been tested in QEMU 2.9.0 but should work in at least 2.5.0 as well. Enabling TPMv2 support ---------------------- To emulate a TPM the swtpm package may be used. It can be built from the following repositories: https://github.com/stefanberger/swtpm.git Swtpm provides a socket for the TPM emulation which can be consumed by QEMU. In a first console invoke swtpm with:: swtpm socket --tpmstate dir=/tmp/mytpm1 \ --ctrl type=unixio,path=/tmp/mytpm1/swtpm-sock --log level=20 In a second console invoke qemu-system-aarch64 with:: -chardev socket,id=chrtpm,path=/tmp/mytpm1/swtpm-sock \ -tpmdev emulator,id=tpm0,chardev=chrtpm \ -device tpm-tis-device,tpmdev=tpm0 Enable the TPM on U-Boot's command line with:: tpm2 startup TPM2_SU_CLEAR Debug UART ---------- The debug UART on the ARM virt board uses these settings:: CONFIG_DEBUG_UART=y CONFIG_DEBUG_UART_PL010=y CONFIG_DEBUG_UART_BASE=0x9000000 CONFIG_DEBUG_UART_CLOCK=0