Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu> says:

This patch series adds basic support for the boards based on Airoha
EN7523/EN7529/EN7562 SoCs. Due to ATF restrictions these boards are
able to run 32-bit OS only.

This patch series adds support for the following hardware:
 * console UART
 * ethernet controller/switch
 * spinand flash (in non-dma mode)

The following issues may be expected:
 * Extra slow UBI attaching in U-Boot (up to 20 sec with fastmap enabled).
   This is caused by the lack of DMA support in the U-Boot airoha-snfi driver.
 * Linux airoha-snfi driver in some cases might damage you flash data
   (see: https://lore.kernel.org/lkml/20251012121707.2296160-15-mikhail.kshevetskiy@iopsys.eu/)
 * Latest linux kernel is recommended to properly support flashes
   with more than one plane per lun
   (see: https://lore.kernel.org/lkml/20251012121707.2296160-7-mikhail.kshevetskiy@iopsys.eu/)
 * It's NOT recommended to use flashes working in continuous mode because
   U-Boot airoha-snfi driver does not support such flashes properly.

The patches was tested on the board:
 - SoC: Airoha EN7562
 - RAM: 512 MB
 - SPI NAND: 4 Gbit, made by Toshiba
 - Linux boot: was NOT tested

The U-Boot was chain-loaded from the running U-Boot. Airoha ATF-2.3 does
not allow easily chain-loading of U-Boot from U-Boot, so a special FIT
image (mimic linux kernel) was created

1) Create u-boot.its file with the following contents:

=== cut here ===
/dts-v1/;

/ {
	description = "ARM OpenWrt FIT (Flattened Image Tree)";
	#address-cells = <1>;

	images {
		u-boot-ram {
			description = "OpenWrt U-Boot RAM image";
			data = /incbin/("u-boot.bin.lzma");
			type = "kernel";
			arch = "arm";
			os = "linux";
			compression = "lzma";
			load = <0x81e00000>;
			entry = <0x81e00000>;
			hash@1 {
				algo = "crc32";
			};
			hash@2 {
				algo = "sha1";
			};
		};

		fdt-1 {
			description = "OpenWrt device tree blob";

			data = /incbin/("dts/upstream/src/arm/airoha/en7523-evb.dtb");
			type = "flat_dt";

			arch = "arm";
			compression = "none";
			hash@1 {
				algo = "crc32";
			};
			hash@2 {
				algo = "sha1";
			};
		};
	};

	configurations {
		default = "config-ram-uboot";
		config-ram-uboot {
			description = "OpenWrt RAM U-Boot";
			kernel = "u-boot-ram";
			fdt = "fdt-1";
		};
	};
};
==================

2) Create u-boot.itb image to chain-load new u-boot from the old one

  lzma_alone e u-boot.bin u-boot.bin.lzma
  mkimage -f u-boot.its u-boot.itb

3) Load new u-boot from the old one

  U-Boot> tftpboot u-boot.itb && bootm

Link: https://lore.kernel.org/r/20251101004503.2379529-1-mikhail.kshevetskiy@iopsys.eu

Basic support for en7523/en7529/en7562 SoCs. Within a patch
only serial console will be supported.

Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>

Add initial support for Airoha AN7581 SoC. This adds the initial Kconfig
and Makefile entry for the SoC, an U-Boot specific DTSI and initial config
for it. Also add the initial code for CPU and RAM initialization.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>