mediatek: mt7623: add full system image for UniElec U7623

This adds a full eMMC image including U-Boot, which means that the
kernel can inherit the true RAM size detected by the preloader.

As implemented in previous commits, sysupgrade to this image from
the legacy layout (and via that, from the vendor-installed image)
is supported.

Rename the legacy image for the 512MiB board, for clarity.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

target/linux/mediatek/image/Config.in

@@ -1,4 +1,4 @@
 config MTK_BOOT_PARTSIZE
        int "Boot (SD Card/eMMC) filesystem partition size (in MiB)"
-       depends on TARGET_mediatek_mt7623_DEVICE_bpi_bananapi-r2 || TARGET_DEVICE_mediatek_mt7623_DEVICE_bpi_bananapi-r2
+       depends on TARGET_mediatek_mt7623_DEVICE_bpi_bananapi-r2 || TARGET_DEVICE_mediatek_mt7623_DEVICE_bpi_bananapi-r2 || TARGET_mediatek_mt7623_DEVICE_unielec_u7623-emmc || TARGET_DEVICE_mediatek_mt7623_DEVICE_unielec_u7623-emmc
        default 32

target/linux/mediatek/image/mt7623.mk

@@ -55,10 +55,33 @@ define Device/bpi_bananapi-r2
 endef
 TARGET_DEVICES += bpi_bananapi-r2
 
-define Device/unielec_u7623-02-emmc-512m
+# Full eMMC image including U-Boot and partition table
+define Device/unielec_u7623-emmc
+  DEVICE_VENDOR := UniElec
+  DEVICE_MODEL := U7623
+  DEVICE_VARIANT := eMMC
+  # When we use FIT images, U-Boot will populate the /memory node with the correct
+  # memory size discovered from the preloader, so we don't need separate builds.
+  DEVICE_DTS := mt7623a-unielec-u7623-02-emmc-512m
+  SUPPORTED_DEVICES := unielec,u7623-02-emmc-512m
+  UBOOT_ENVSIZE := 0x1000
+  UBOOT_OFFSET := 256k
+  UBOOT_TARGET := mt7623a_unielec_u7623
+  IMAGES := img.gz
+  IMAGE/img.gz := mtk-mmc-img | gzip | append-metadata
+  DEVICE_PACKAGES := kmod-fs-vfat kmod-nls-cp437 kmod-nls-iso8859-1 kmod-mmc \
+       mkf2fs e2fsprogs kmod-usb-ohci kmod-usb2 kmod-usb3 kmod-ata-ahci-mtk
+  ARTIFACT/scatter.txt := scatterfile $$(firstword $$(FILESYSTEMS))-$$(firstword $$(IMAGES))
+  ARTIFACTS := scatter.txt
+endef
+TARGET_DEVICES += unielec_u7623-emmc
+
+# Legacy partial image for U7623
+# This preserves the vendor U-Boot and starts with a uImage at 0xA00
+define Device/unielec_u7623-02-emmc-512m-legacy
   DEVICE_VENDOR := UniElec
   DEVICE_MODEL := U7623-02
-  DEVICE_VARIANT := eMMC/512MB RAM
+  DEVICE_VARIANT := eMMC/512MiB RAM (legacy image)
   DEVICE_DTS := mt7623a-unielec-u7623-02-emmc-512m
   KERNEL_NAME := zImage
   KERNEL := kernel-bin | append-dtb | uImage none
@@ -67,5 +90,6 @@ define Device/unielec_u7623-02-emmc-512m
 	mkf2fs e2fsprogs kmod-usb-ohci kmod-usb2 kmod-usb3 kmod-ata-ahci-mtk
   IMAGES := sysupgrade-emmc.bin.gz
   IMAGE/sysupgrade-emmc.bin.gz := sysupgrade-emmc | gzip | append-metadata
+  SUPPORTED_DEVICES := unielec,u7623-02-emmc-512m
 endef
-TARGET_DEVICES += unielec_u7623-02-emmc-512m
+TARGET_DEVICES += unielec_u7623-02-emmc-512m-legacy

target/linux/mediatek/image/mt7623a_unielec_u7623-uEnv.txt

@@ -0,0 +1,20 @@
+# Boot menu for UniElec U7623
+# Copyright © 2020 David Woodhouse <dwmw2@infradead.org>
+
+kernel=uImage
+loadaddr=0x88000000
+dtaddr=0x83f00000
+fdt_high=0xafffffff
+
+console=ttyS0,115200
+bootopts=rootfstype=squashfs,ext4 rootwait
+
+# Create the command line (with appropriate root=) and boot the Linux FIT image.
+boot1=setenv bootargs "console=${console} root=${rootdev} ${bootopts}";printenv bootargs;\
+ fatload mmc ${partition} ${loadaddr} ${kernel}; bootm
+
+bootmenu_0=Boot from eMMC.=setenv partition 0:2;setenv rootdev /dev/mmcblk0p3;run boot1
+bootmenu_default=0
+
+bootdelay=0
+bootcmd=bootmenu