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Tuomas Tynkkynena1c21782017-10-09 19:42:41 +03001#
2# Copyright (C) 2017, Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
3#
4# SPDX-License-Identifier: GPL-2.0+
5#
6
Tuomas Tynkkynen87145cf2018-01-11 16:11:24 +02007U-Boot on QEMU's 'virt' machine on ARM & AArch64
8================================================
Tuomas Tynkkynena1c21782017-10-09 19:42:41 +03009
10QEMU for ARM supports a special 'virt' machine designed for emulation and
11virtualization purposes. This document describes how to run U-Boot under it.
Tuomas Tynkkynen87145cf2018-01-11 16:11:24 +020012Both 32-bit ARM and AArch64 are supported.
Tuomas Tynkkynena1c21782017-10-09 19:42:41 +030013
14The 'virt' platform provides the following as the basic functionality:
15
16 - A freely configurable amount of CPU cores
17 - U-Boot loaded and executing in the emulated flash at address 0x0
18 - A generated device tree blob placed at the start of RAM
19 - A freely configurable amount of RAM, described by the DTB
20 - A PL011 serial port, discoverable via the DTB
Tuomas Tynkkynen87145cf2018-01-11 16:11:24 +020021 - An ARMv7/ARMv8 architected timer
Tuomas Tynkkynena1c21782017-10-09 19:42:41 +030022 - PSCI for rebooting the system
23 - A generic ECAM-based PCI host controller, discoverable via the DTB
24
25Additionally, a number of optional peripherals can be added to the PCI bus.
26
27Building U-Boot
28---------------
Tuomas Tynkkynen87145cf2018-01-11 16:11:24 +020029Set the CROSS_COMPILE environment variable as usual, and run:
Tuomas Tynkkynena1c21782017-10-09 19:42:41 +030030
Tuomas Tynkkynen87145cf2018-01-11 16:11:24 +020031- For ARM:
Tuomas Tynkkynena1c21782017-10-09 19:42:41 +030032 make qemu_arm_defconfig
33 make
34
Tuomas Tynkkynen87145cf2018-01-11 16:11:24 +020035- For AArch64:
36 make qemu_arm64_defconfig
37 make
38
Tuomas Tynkkynena1c21782017-10-09 19:42:41 +030039Running U-Boot
40--------------
41The minimal QEMU command line to get U-Boot up and running is:
42
Tuomas Tynkkynen87145cf2018-01-11 16:11:24 +020043- For ARM:
Tuomas Tynkkynena1c21782017-10-09 19:42:41 +030044 qemu-system-arm -machine virt,highmem=off -bios u-boot.bin
45
Tuomas Tynkkynen87145cf2018-01-11 16:11:24 +020046- For AArch64:
47 qemu-system-aarch64 -machine virt,highmem=off -cpu cortex-a57 -bios u-boot.bin
48
Tuomas Tynkkynena1c21782017-10-09 19:42:41 +030049The 'highmem=off' parameter to the 'virt' machine is required for PCI to work
Tuomas Tynkkynen87145cf2018-01-11 16:11:24 +020050in U-Boot. Also, for some odd reason qemu-system-aarch64 needs to be explicitly
51told to use a 64-bit CPU or it will boot in 32-bit mode.
Tuomas Tynkkynena1c21782017-10-09 19:42:41 +030052
53Additional peripherals that have been tested to work in both U-Boot and Linux
54can be enabled with the following command line parameters:
55
56- To add a Serial ATA disk via an Intel ICH9 AHCI controller, pass e.g.:
57 -drive if=none,file=disk.img,id=mydisk -device ich9-ahci,id=ahci -device ide-drive,drive=mydisk,bus=ahci.0
58- To add an Intel E1000 network adapter, pass e.g.:
59 -netdev user,id=net0 -device e1000,netdev=net0
60- To add an EHCI-compliant USB host controller, pass e.g.:
61 -device usb-ehci,id=ehci
62- To add a NVMe disk, pass e.g.:
63 -drive if=none,file=disk.img,id=mydisk -device nvme,drive=mydisk,serial=foo
64
65These have been tested in QEMU 2.9.0 but should work in at least 2.5.0 as well.