armsr: enable framebuffer emulation for virtio-gpu/drm displays

This was discovered when trying to run OpenWrt on Hetzner Cloud's
Arm-based instances.

Hetzner uses QEMU/KVM with virtio-gpu as the main display device,
together with an ACPI firmware. This was not displaying a console
previously.

This setup can be emulated by qemu using options below:
qemu-system-aarch64 \
    -machine virt \
    -bios QEMU_EFI.fd \
    -device virtio-gpu \
    -usb \
    -device qemu-xhci,id=xhci \
    -device usb-tablet,bus=xhci.0 \
    -device usb-kbd,bus=xhci.0 \
    -vnc :0

Signed-off-by: Mathew McBride <matt@traverse.com.au>
(cherry picked from commit ea7383e7215c36e47a769f34c57aa458300b8bc2)
Link: https://github.com/openwrt/openwrt/pull/15808
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

diff --git a/target/linux/armsr/config-5.15 b/target/linux/armsr/config-5.15
index a9273e64894285ced7d96aa5943caf4782decd13..080d084efbb44d2f0fadc19e9da3c4f6e9464490 100644 (file)
--- a/target/linux/armsr/config-5.15
+++ b/target/linux/armsr/config-5.15
@@ -99,6 +99,9 @@ CONFIG_DMA_REMAP=y
 CONFIG_DMI=y
 CONFIG_DMIID=y
 CONFIG_DMI_SYSFS=y
+CONFIG_DRM_FBDEV_EMULATION=y
+CONFIG_DRM_FBDEV_OVERALLOC=100
+CONFIG_DRM_LOAD_EDID_FIRMWARE=y
 CONFIG_DTC=y
 CONFIG_EDAC_SUPPORT=y
 CONFIG_EFI=y