diff options
| author | Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi> | 2018-01-11 16:11:24 +0200 |
|---|---|---|
| committer | Tom Rini <trini@konsulko.com> | 2018-01-19 15:49:31 -0500 |
| commit | e7ba41c6539f7843914d187e4e6d5d618a3039fe (patch) | |
| tree | 2356a475aaad1958e18af016e9f58907c8024bc4 /doc | |
| parent | ddcca73051060f11802da7ddaa5e1d66b12025c4 (diff) | |
ARM: Document AArch64 version of qemu-arm
It's mostly obvious, except that QEMU is annoying and requires an
explicit '-cpu cortex-a57' (or some other 64-bit core) to actually run
in 64-bit mode.
While at it, remove the references to setting the ARCH environment
variable; that is not used in U-Boot.
Signed-off-by: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
Reviewed-by: Tom Rini <trini@konsulko.com>
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/README.qemu-arm | 21 |
1 files changed, 16 insertions, 5 deletions
diff --git a/doc/README.qemu-arm b/doc/README.qemu-arm index 2895e3b97f..aee789447a 100644 --- a/doc/README.qemu-arm +++ b/doc/README.qemu-arm @@ -4,11 +4,12 @@ # SPDX-License-Identifier: GPL-2.0+ # -U-Boot on QEMU's 'virt' machine on ARM -====================================== +U-Boot on QEMU's 'virt' machine on ARM & AArch64 +================================================ 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: @@ -17,7 +18,7 @@ The 'virt' platform provides the following as the basic functionality: - 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 + - An ARMv7/ARMv8 architected timer - PSCI for rebooting the system - A generic ECAM-based PCI host controller, discoverable via the DTB @@ -25,19 +26,29 @@ 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: +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,highmem=off -bios u-boot.bin +- For AArch64: + qemu-system-aarch64 -machine virt,highmem=off -cpu cortex-a57 -bios u-boot.bin + The 'highmem=off' parameter to the 'virt' machine is required for PCI to work -in U-Boot. +in U-Boot. Also, 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 peripherals that have been tested to work in both U-Boot and Linux can be enabled with the following command line parameters: |