Add splash

[m-iwanicki]

• Add splash in U-Boot, kernel and userspace (psplash).
• Add patch with VOP2 & HDMI drivers so we can enable display in U-Boot.
• Add patch with virtio-gpu drivers so we can enable display in U-Boot on QEMU (should probably be moved to meta-zarhus-bsp-qemuarm-uboot: Add qemuarm-uboot machine #47 before merge) - moved to meta-zarhus-bsp-qemuarm-uboot: Add qemuarm-uboot machine #47
• Download, convert and optionally resize logo for each stage (so it fills the screen)
• Enable framebuffer passing between U-Boot and kernel (needs to be tested, might not work) - at least reserved memory works (so framebuffer isn't overridden), framebuffer passing would need some kind of test to make sure it works.
• Fix orange-pi device-tree paths

TODO:

• Before merge: remove 6084281, should probably be set individually for each platform. - Done, left only 86e9ecc which can be overridden in e.g. kas config file. To enable splash add splash to DISTRO_FEATURES or add DISTRO_FEATURES_DEFAULT:append = " splash" inside kas file
• Better readme for qemu - should be done in meta-zarhus-bsp-qemuarm-uboot: Add qemuarm-uboot machine #47
• Maybe create framebuffer and reserved memory nodes dynamically in U-Boot - possible improvement for future

Tested on Radxa-cm3 and QEMU. As of now display signal is lost when booting kernel (on HDMI and QEMU).
HDMI monitor on Radxa is very slow to start up after losing signal so usually before you see anything Linux manages to almost boot to login prompt (so you see only brief psplash logo).
On QEMU it's easier to see each stage as display is enabled quite early in kernel stage.

[m-iwanicki]

@macpijan splash on QEMU:

1-flicker.mp4

Without 0001-virtio_gpu-remove-DM_FLAG_ACTIVE_DMA-to-keep-splash.patch patch there is much longer Display output not active (until kernel initializes driver).
I also tested device-tree with framebuffer (to deal with flicker) but hadn't managed yet. One config that results in no errors in dmesg is (how to get dtb in and out: https://docs.u-boot.org/en/latest/develop/devicetree/dt_qemu.html):

    reserved-memory {
        #address-cells = <2>;
        #size-cells = <2>;
        ranges;
        
        fb: framebuffer@7fe00000 {
            compatible = "framebuffer";
            reg = <0 0x7fe00000 0 0xa00000>;
            no-map;
        };
    };

	chosen {
		bootargs = "root=PARTLABEL=root rw ip=dhcp swiotlb=0 quiet splash";
		stdout-path = "/pl011@9000000";
		rng-seed = <0x3da86298 0xbe5d7724 0x11f59fc5 0xae4cd81b 0xe4efb4ea 0xc1e46854 0xc69fe738 0x95153740>;
		kaslr-seed = <0x3ffc7adc 0xb71d3355>;
		#address-cells = <2>;
		#size-cells = <2>;
		ranges;
        
		framebuffer@7fe00000 {
			compatible = "simple-framebuffer";
			reg = <0 0x7fe00000 0 (640 * 480 * 4)>;
			width = <640>;
			height = <480>;
			stride = <(640 * 4)>;
			format = "a8r8g8b8";
			memory-region = <&fb>;
		};
	};

But results in Display output is not active and second framebuffer being allocated (fb1) by gpu driver (virtio-pci/virtio_gpudrmfb). You can show image by using e.g. psplash -f 1 or by adding fbcon=map:1 to cmdline (to show kernel logs on fb1) but that's not what we want.
There is also small flicker between kernel logo and psplash but I didn't check why.

[m-iwanicki]

This recipe only function is to prepare logo for u-boot (resize and convert to BMP).
Not sure which part does this license apply to as the only file we download is Zarhus Logo.

Forgot that one thread is still open.