1# 2# Copyright (C) 2017, Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi> 3# 4# SPDX-License-Identifier: GPL-2.0+ 5# 6 7U-Boot on QEMU's 'virt' machine on ARM 8====================================== 9 10QEMU for ARM supports a special 'virt' machine designed for emulation and 11virtualization purposes. This document describes how to run U-Boot under it. 12 13The 'virt' platform provides the following as the basic functionality: 14 15 - A freely configurable amount of CPU cores 16 - U-Boot loaded and executing in the emulated flash at address 0x0 17 - A generated device tree blob placed at the start of RAM 18 - A freely configurable amount of RAM, described by the DTB 19 - A PL011 serial port, discoverable via the DTB 20 - An ARMv7 architected timer 21 - PSCI for rebooting the system 22 - A generic ECAM-based PCI host controller, discoverable via the DTB 23 24Additionally, a number of optional peripherals can be added to the PCI bus. 25 26Building U-Boot 27--------------- 28Set the CROSS_COMPILE and ARCH=arm environment variables as usual, and run: 29 30 make qemu_arm_defconfig 31 make 32 33Running U-Boot 34-------------- 35The minimal QEMU command line to get U-Boot up and running is: 36 37 qemu-system-arm -machine virt,highmem=off -bios u-boot.bin 38 39The 'highmem=off' parameter to the 'virt' machine is required for PCI to work 40in U-Boot. 41 42Additional peripherals that have been tested to work in both U-Boot and Linux 43can be enabled with the following command line parameters: 44 45- To add a Serial ATA disk via an Intel ICH9 AHCI controller, pass e.g.: 46 -drive if=none,file=disk.img,id=mydisk -device ich9-ahci,id=ahci -device ide-drive,drive=mydisk,bus=ahci.0 47- To add an Intel E1000 network adapter, pass e.g.: 48 -netdev user,id=net0 -device e1000,netdev=net0 49- To add an EHCI-compliant USB host controller, pass e.g.: 50 -device usb-ehci,id=ehci 51- To add a NVMe disk, pass e.g.: 52 -drive if=none,file=disk.img,id=mydisk -device nvme,drive=mydisk,serial=foo 53 54These have been tested in QEMU 2.9.0 but should work in at least 2.5.0 as well. 55