mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-05 20:54:31 +00:00
c6963fb88f
Provide the settings for the debug UART on the QEMU ARM virt board. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
92 lines
2.6 KiB
ReStructuredText
92 lines
2.6 KiB
ReStructuredText
.. SPDX-License-Identifier: GPL-2.0+
|
|
.. Copyright (C) 2017, Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
|
|
|
|
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.
|
|
|
|
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 -bios u-boot.bin
|
|
|
|
- For AArch64::
|
|
|
|
qemu-system-aarch64 -machine virt -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.
|
|
|
|
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,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.
|
|
|
|
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
|