mediatek: rework Bananapi BPi-R2

 * introduce recovery (=initramfs) vs. production dual boot scheme
 * make use of uImage.FIT (instead of FAT partition)
 * generate images using build steps (instead of external scripts)
 * simplify sysupgrade and config restore (thanks to uImage.FIT)
 * make sure mmc devices are ordered persistently (set DT aliases)

This commit breaks sysupgrade from existing installations, you will
have to re-install using the sdcard.img.gz image.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

1 files changed, 104 insertions, 40 deletions

diff --git a/target/linux/mediatek/image/mt7623.mk b/target/linux/mediatek/image/mt7623.mk
index 56f67c0e89..c404b333ba 100644
--- a/target/linux/mediatek/image/mt7623.mk
+++ b/target/linux/mediatek/image/mt7623.mk
@@ -1,59 +1,123 @@
 KERNEL_LOADADDR := 0x80008000
 DEVICE_VARS += UBOOT_TARGET UBOOT_OFFSET UBOOT_ENVSIZE
 
-ifneq ($(CONFIG_MTK_BOOT_PARTSIZE),)
-BOOTFS_BLOCK_SIZE := 1024
-BOOTFS_BLOCKS := $(shell echo $$(($(CONFIG_MTK_BOOT_PARTSIZE)*1024*1024/$(BOOTFS_BLOCK_SIZE))))
-endif
+# The bootrom of MT7623 expects legacy MediaTek headers present in
+# exactly the location also used for the primary GPT partition table.
+# (*MMC_BOOT and BRLYT)
+# Hence only MSDOS/MBR partitioning can work here.
+#
+#   ------------------------   Sector   Offset
+#   |  MBR + SDMMC_BOOT    |     0       0x0
+#   |----------------------|
+#   |     BRLYT header     |     1       0x200
+#   |----------------------|
+#   .                      .
+#   .                      .
+#   |----------------------|
+#   |                      |     4       0x800
+#   |                      |
+#   |     Preloader        |
+#   .                      .
+#   .                      .
+#   |                      |     639
+#   |----------------------|
+#   |   MBR partition #1   |     640     0x50000
+#   |                      |
+#   |       U-Boot         |
+#   .                      .
+#   .                      .
+#   |                      |     1663
+#   |----------------------|
+#   |   MBR partition #2   |
+#   |                      |
+#   |       Recovery       |
+#   .                      .
+#   .     (uImage.FIT)     .
+#   |                      |
+#   |----------------------|
+#   |   MBR partition #3   |
+#   |                      |
+#   |      Production      |
+#   |                      |
+#   |     (uImage.FIT,     |
+#   .     rootfs_Data.)    .
+#   .                      .
+#   |                      |
+#   ------------------------
+#
+# For eMMC boot, everything up to and including the preloader must be
+# written to /dev/mmcblk0boot0, with the SDMMC_BOOT header changed to
+# read EMMC_BOOT\0 instead.
+#
+# The contents of the main eMMC are identical to the SD card layout,
+# with the preloader loading 512KiB of U-Boot starting at 0x50000.
 
-define Build/mtk-mmc-img
-	rm -f $@.boot
-	mkfs.fat -C $@.boot $(BOOTFS_BLOCKS)
+define Build/mt7623-mbr
+	cp $@ $@.tmp 2>/dev/null || true
+	ptgen -o $@.tmp -h 4 -s 63 -a 0 -l 1024 \
+			-t 0x41	-N uboot	-p 3584k@320k \
+			-t 0xea	-N recovery	-p 40M@4M \
+		$(if $(findstring sdmmc,$1), \
+			-t 0x2e -N production	-p 208M@48M \
+		) \
+		$(if $(findstring emmc,$1), \
+			-t 0x2e -N production	-p 976M@48M \
+		)
 
-	if [ -r $(STAGING_DIR_IMAGE)/$(UBOOT_TARGET)-preloader.bin ]; then \
-		./gen_mtk_mmc_img.sh emmc $@.emmc \
-			$(STAGING_DIR_IMAGE)/$(UBOOT_TARGET)-preloader.bin; \
-		mcopy -i $@.boot $@.emmc ::eMMCboot.bin; \
-	fi
-	mkenvimage -s $(UBOOT_ENVSIZE) -o $(STAGING_DIR_IMAGE)/$(UBOOT_TARGET)-uboot.env $(UBOOT_TARGET)-uEnv.txt
-	mcopy -i $@.boot $(STAGING_DIR_IMAGE)/$(UBOOT_TARGET)-uboot.env ::uboot.env
-	mcopy -i $@.boot $(IMAGE_KERNEL) ::uImage
-	./gen_mtk_mmc_img.sh sd $@ \
-		$(STAGING_DIR_IMAGE)/$(UBOOT_TARGET)-preloader.bin \
-		$(STAGING_DIR_IMAGE)/$(UBOOT_TARGET)-u-boot*.bin \
-		$(UBOOT_OFFSET) \
-		$@.boot \
-		$(IMAGE_ROOTFS) \
-		$(CONFIG_MTK_BOOT_PARTSIZE) \
-		$(CONFIG_TARGET_ROOTFS_PARTSIZE)
+	echo -en \
+		$(if $(findstring sdmmc,$1),"SDMMC_BOOT\x00\x00\x01\x00\x00\x00\x00\x02\x00\x00") \
+		$(if $(findstring emmc,$1),"EMMC_BOOT\x00\x00\x00\x01\x00\x00\x00\x00\x02\x00\x00") \
+		| dd bs=1 of="$@.tmp" seek=0 conv=notrunc
+
+	echo -en "BRLYT\x00\x00\x00\x01\x00\x00\x00\x00\x08\x00\x00\x00\x08\x00\x00\x42\x42\x42\x42\x08\x00\x01\x00\x00\x08\x00\x00\x00\x08\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"\
+		| dd bs=1 of="$@.tmp" seek=512 conv=notrunc
+
+	cat $@.tmp >> $@
+	rm $@.tmp
 endef
 
-define Build/preloader
-	$(CP) $(STAGING_DIR_IMAGE)/$1-preloader.bin $@
+define Build/append-preloader
+	cat $(STAGING_DIR_IMAGE)/$1-preloader.bin >> $@
 endef
 
-define Build/scatterfile
-	./gen_scatterfile.sh $(subst mt,MT,$(SUBTARGET)) "$1" \
-		$(subst -scatter.txt,,$(notdir $@)) "$(DEVICE_TITLE)" > $@
+define Build/append-bootloader
+	cat $(STAGING_DIR_IMAGE)/$1-u-boot.bin >> $@
 endef
 
-define Device/bpi_bananapi-r2
-  DEVICE_VENDOR := Bpi
-  DEVICE_MODEL := Banana Pi R2
+define Device/bananapi_bpi-r2
+  DEVICE_VENDOR := Bananapi
+  DEVICE_MODEL := BPi-R2
   DEVICE_DTS := mt7623n-bananapi-bpi-r2
-  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
-  UBOOT_ENVSIZE := 0x2000
+  DEVICE_PACKAGES := kmod-mmc mkf2fs e2fsprogs kmod-usb3 kmod-ata-ahci
+  UBOOT_ENVSIZE := 0x10000
   UBOOT_OFFSET := 320k
   UBOOT_TARGET := mt7623n_bpir2
-  IMAGES := img.gz
-  IMAGE/img.gz := mtk-mmc-img | gzip | append-metadata
-  ARTIFACT/preloader.bin := preloader $$(UBOOT_TARGET)
-  ARTIFACT/scatter.txt := scatterfile $$(firstword $$(FILESYSTEMS))-$$(firstword $$(IMAGES))
-  ARTIFACTS = preloader.bin scatter.txt
+  UBOOT_PATH := $(STAGING_DIR_IMAGE)/mt7623n_bpir2-u-boot.bin
+  IMAGES := sysupgrade.itb
+  KERNEL := kernel-bin | gzip
+  KERNEL_INITRAMFS_SUFFIX := -recovery.itb
+  KERNEL_INITRAMFS := kernel-bin | gzip | fit gzip $$(DTS_DIR)/$$(DEVICE_DTS).dtb with-initrd
+  IMAGE/sysupgrade.itb := append-kernel | fit gzip $$(DTS_DIR)/$$(DEVICE_DTS).dtb external-static-with-rootfs | append-metadata
+  ARTIFACT/preloader.bin := append-preloader $$(UBOOT_TARGET)
+  ARTIFACT/u-boot.bin := append-uboot
+  ARTIFACT/sdcard.img.gz := mt7623-mbr sdmmc |\
+			    pad-to 2k | append-preloader $$(UBOOT_TARGET) |\
+			    pad-to 320k | append-bootloader $$(UBOOT_TARGET) |\
+			    pad-to 4092k | mt7623-mbr emmc |\
+			    pad-to 4M | append-image-stage initramfs-recovery.itb |\
+			    pad-to 48M | append-image squashfs-sysupgrade.itb |\
+			    gzip
+  ARTIFACTS = u-boot.bin preloader.bin scatter.txt sdcard.img.gz
   SUPPORTED_DEVICES := bananapi,bpi-r2
 endef
-TARGET_DEVICES += bpi_bananapi-r2
+TARGET_DEVICES += bananapi_bpi-r2
+
+
+
+define Build/scatterfile
+	./gen_scatterfile.sh $(subst mt,MT,$(SUBTARGET)) "$1" \
+		$(subst -scatter.txt,,$(notdir $@)) "$(DEVICE_TITLE)" > $@
+endef
 
 # Full eMMC image including U-Boot and partition table
 define Device/unielec_u7623-emmc