diff mbox series

[U-Boot,v2,2/4] ARM: Document AArch64 version of qemu-arm

Message ID 20180111141126.15432-3-tuomas.tynkkynen@iki.fi
State Accepted
Commit e7ba41c6539f7843914d187e4e6d5d618a3039fe
Delegated to: Tom Rini
Headers show
Series ARM: Extend qemu_arm to support ARM64 | expand

Commit Message

Tuomas Tynkkynen Jan. 11, 2018, 2:11 p.m. UTC 
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>
---
v2: Drop ARCH=arm as it turns out not to be needed in U-Boot.
---
 doc/README.qemu-arm | 21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

Comments

Tom Rini Jan. 11, 2018, 3:14 p.m. UTC | #1 
On Thu, Jan 11, 2018 at 04:11:24PM +0200, Tuomas Tynkkynen wrote:

> 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>
Tom Rini Jan. 19, 2018, 9:14 p.m. UTC | #2 
On Thu, Jan 11, 2018 at 04:11:24PM +0200, Tuomas Tynkkynen wrote:

> 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>

Applied to u-boot/master, thanks!
diff mbox series

Patch

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: