From d5587fa308c937a598fd10918593458e48040f14 Mon Sep 17 00:00:00 2001 From: Tuomas Tynkkynen Date: Mon, 9 Oct 2017 19:42:41 +0300 Subject: [PATCH] ARM: Add documentation for the qemu-arm board Add brief documentation for the recently merged qemu-arm board. Signed-off-by: Tuomas Tynkkynen --- doc/README.qemu-arm | 54 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 doc/README.qemu-arm diff --git a/doc/README.qemu-arm b/doc/README.qemu-arm new file mode 100644 index 0000000000..2895e3b97f --- /dev/null +++ b/doc/README.qemu-arm @@ -0,0 +1,54 @@ +# +# Copyright (C) 2017, Tuomas Tynkkynen +# +# SPDX-License-Identifier: GPL-2.0+ +# + +U-Boot on QEMU's 'virt' machine on 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. + +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 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. + +Building U-Boot +--------------- +Set the CROSS_COMPILE and ARCH=arm environment variables as usual, and run: + + make qemu_arm_defconfig + make + +Running U-Boot +-------------- +The minimal QEMU command line to get U-Boot up and running is: + + qemu-system-arm -machine virt,highmem=off -bios u-boot.bin + +The 'highmem=off' parameter to the 'virt' machine is required for PCI to work +in U-Boot. + +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,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 a NVMe disk, pass e.g.: + -drive if=none,file=disk.img,id=mydisk -device nvme,drive=mydisk,serial=foo + +These have been tested in QEMU 2.9.0 but should work in at least 2.5.0 as well. -- 2.25.1