[Buildroot] [PATCH] qemu: Change CPU in qemu command for aarch64

[Buildroot] [PATCH] qemu: Change CPU in qemu command for aarch64

[Gerome Burlats]

This commit changes to "cortex-a53" the CPU model in the qemu command for aarch64 (since it is the default one for this architecture).

Signed-off-by: Gerome Burlats <gerome.burlats@smile.fr>
Cc: Romain Naour <romain.naour@smile.fr>
---

cortex-a53 is the default cpu for aarch64, but some defconfigs, for example raspberrypi3_64_defconfig, still have "BR2_cortex_a53=y" (maybe at one point, this cpu was not the default).
Should this line stay in the defconfig for info, even if it is not used ?
If we generate the defconfig with "make savedefconfig", BR2_cortex_a53=y is indeed not added in the file.
---
 board/qemu/aarch64-virt/readme.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/board/qemu/aarch64-virt/readme.txt b/board/qemu/aarch64-virt/readme.txt
index 76fc2d6f32..1ff2fba47d 100644
--- a/board/qemu/aarch64-virt/readme.txt
+++ b/board/qemu/aarch64-virt/readme.txt
@@ -1,6 +1,6 @@
 Run the emulation with:
 
-  qemu-system-aarch64 -M virt -cpu cortex-a57 -nographic -smp 1 -kernel output/images/Image -append "root=/dev/vda console=ttyAMA0" -netdev user,id=eth0 -device virtio-net-device,netdev=eth0 -drive file=output/images/rootfs.ext4,if=none,format=raw,id=hd0 -device virtio-blk-device,drive=hd0
+  qemu-system-aarch64 -M virt -cpu cortex-a53 -nographic -smp 1 -kernel output/images/Image -append "root=/dev/vda console=ttyAMA0" -netdev user,id=eth0 -device virtio-net-device,netdev=eth0 -drive file=output/images/rootfs.ext4,if=none,format=raw,id=hd0 -device virtio-blk-device,drive=hd0
 
 The login prompt will appear in the terminal that started Qemu.
 
-- 
2.20.1

[Buildroot] [PATCH] qemu: Change CPU in qemu command for aarch64

[Peter Korsgaard]

>>>>> "Gerome" == Gerome Burlats <gerome.burlats@smile.fr> writes:

 > This commit changes to "cortex-a53" the CPU model in the qemu command
 > for aarch64 (since it is the default one for this architecture).

 > Signed-off-by: Gerome Burlats <gerome.burlats@smile.fr>
 > Cc: Romain Naour <romain.naour@smile.fr>
 > ---

 > cortex-a53 is the default cpu for aarch64, but some defconfigs, for
 > example raspberrypi3_64_defconfig, still have "BR2_cortex_a53=y"
 > (maybe at one point, this cpu was not the default).
 > Should this line stay in the defconfig for info, even if it is not used ?
 > If we generate the defconfig with "make savedefconfig", BR2_cortex_a53=y is indeed not added in the file.

Correct. We typically do add for clarity and robustness against changes
of the default value.

It is correct that savedefconfig will strip such redundant entries, but
as you can see from the comments, qemu_aarch64_virt_defconfig is edited
by hand.

Committed after extending the commit message and adding an explicit
BR2_cortex_a53=y to the defconfig, thanks.

-- 
Bye, Peter Korsgaard

[Buildroot] [PATCH] qemu: Change CPU in qemu command for aarch64

[Peter Korsgaard]

>>>>> "Peter" == Peter Korsgaard <peter@korsgaard.com> writes:

>>>>> "Gerome" == Gerome Burlats <gerome.burlats@smile.fr> writes:
 >> This commit changes to "cortex-a53" the CPU model in the qemu command
 >> for aarch64 (since it is the default one for this architecture).

 >> Signed-off-by: Gerome Burlats <gerome.burlats@smile.fr>
 >> Cc: Romain Naour <romain.naour@smile.fr>
 >> ---

 >> cortex-a53 is the default cpu for aarch64, but some defconfigs, for
 >> example raspberrypi3_64_defconfig, still have "BR2_cortex_a53=y"
 >> (maybe at one point, this cpu was not the default).
 >> Should this line stay in the defconfig for info, even if it is not used ?
 >> If we generate the defconfig with "make savedefconfig", BR2_cortex_a53=y is indeed not added in the file.

 > Correct. We typically do add for clarity and robustness against changes
 > of the default value.

 > It is correct that savedefconfig will strip such redundant entries, but
 > as you can see from the comments, qemu_aarch64_virt_defconfig is edited
 > by hand.

 > Committed after extending the commit message and adding an explicit
 > BR2_cortex_a53=y to the defconfig, thanks.

Committed to 2018.02.x and 2018.11.x, thanks.

-- 
Bye, Peter Korsgaard