motorola-rtwo: raw Image + empty dtbo for the Motorola bootloader

From the stock LineageOS images:
- boot.img carries a raw uncompressed arm64 Image (MZ header), not
  Image.gz. Install arch/arm64/boot/Image as vmlinuz.
- dtbo.img is an 8-entry overlay table; the bootloader applies overlay
  #7 (androidboot.dtbo_idx=7, 87 fragments) onto the base DTB by
  phandle. Against our mainline DTB that produces a corrupt merged tree
  -> instant panic. Ship an empty dtbo (0 entries) to flash to dtbo_b,
  and set deviceinfo_flash_fastboot_partition_dtbo.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QF5HebjUsRaxbW4cBX6HJP

device/testing/device-motorola-rtwo/APKBUILD

@@ -2,7 +2,7 @@
 maintainer="snlavaise <snlavaise@gmail.com>"
 pkgname=device-motorola-rtwo
 pkgver=1
-pkgrel=6
+pkgrel=7
 pkgdesc="Motorola Moto Edge 40 Pro"
 url="https://postmarketos.org"
 arch="aarch64"
@@ -36,6 +36,6 @@ package() {
 }
 
 sha512sums="
-5731bcab1f4b4625b39a72f560be249fb3a89c55d84f81fa983313ab722eacf62ceb427e20833b7f8e7f5399c051d2185db82b1d5ed8b33b850b795127b3eb91  deviceinfo
+e66050dc46b1933b4e3bf7d4918e72ed68218015cc714615b26801030c3f9b481815eba0a01c9795a479353511cb7928d1f1cb0b3dc1b3817ca4c7cd5f1f8301  deviceinfo
 c572e21cb0624b554a22a218b0c4faab9b6412654bed6bfef530f3068d076b21c573bd7f4b3ca65f510f8756f636a861191cce925ef49587db7d68d09558826c  modules-initfs
 "

device/testing/device-motorola-rtwo/deviceinfo

@@ -30,6 +30,7 @@ deviceinfo_create_initfs_extra="true"
 
 # Bootloader related
 deviceinfo_flash_method="fastboot"
+deviceinfo_flash_fastboot_partition_dtbo="dtbo"
 deviceinfo_kernel_cmdline="console=tty0 console=ttyMSM0,115200n8 earlycon clk_ignore_unused pd_ignore_unused ignore_loglevel"
 deviceinfo_generate_bootimg="true"
 # The Motorola bootloader places the DTB / kernel at the addresses in the

device/testing/linux-postmarketos-qcom-sm8550/APKBUILD

@@ -5,7 +5,7 @@ maintainer="snlavaise <snlavaise@gmail.com>"
 _flavor="postmarketos-qcom-sm8550"
 pkgname=linux-$_flavor
 pkgver=7.2
-pkgrel=2
+pkgrel=3
 pkgdesc="Mainline kernel for Qualcomm SM8550 (Snapdragon 8 Gen 2) + Motorola rtwo"
 arch="aarch64"
 _carch="arm64"
@@ -74,12 +74,20 @@ build() {
 }
 
 package() {
-	# The Motorola bootloader wants a plain gzip'd arm64 Image in the
+	# The Motorola bootloader boots a *raw* uncompressed arm64 Image
-	# Android boot.img, NOT the EFI ZBOOT blob (vmlinuz.efi). CONFIG_EFI_ZBOOT
+	# (BOARD_KERNEL_IMAGE_NAME := Image); Image.gz / vmlinuz.efi make it
-	# is disabled in rtwo.config so Image.gz is what gets built.
+	# reset in <2s. CONFIG_EFI_ZBOOT is off in rtwo.config.
-	install -Dm644 "$builddir/arch/$_carch/boot/Image.gz" \
+	install -Dm644 "$builddir/arch/$_carch/boot/Image" \
 		"$pkgdir/boot/vmlinuz"
 
+	# Empty Android DT-overlay table (magic d7b7ab1e, 0 entries). The
+	# bootloader would otherwise apply the stock kalama dtbo overlay onto
+	# our mainline base DTB - the phandles don't match, the merged DTB is
+	# corrupt and the kernel panics. Flash this to the dtbo partition.
+	mkdir -p "$pkgdir"/boot
+	printf '\xd7\xb7\xab\x1e\x00\x00\x00\x20\x00\x00\x00\x20\x00\x00\x00\x20\x00\x00\x00\x00\x00\x00\x00\x20\x00\x00\x08\x00\x00\x00\x00\x00' \
+		> "$pkgdir"/boot/dtbo.img
+
 	make modules_install dtbs_install \
 		ARCH="$_carch" \
 		LLVM=1 \
@@ -98,6 +106,6 @@ package() {
 sha512sums="
 52d5aa7f94f6aa6141debf4ceb4fc7a2e75505a7cd38b8854e501be83c2b57863020f463f2fdb2fc93667e6cfe13274d077e5207a611e4797bd9404ee0e64c58  linux-postmarketos-qcom-sm8550-7.2.tar.gz
 f9ae52489f6b9e6fef64952943cd09732a5bef90a0e8765db03c256483028368687d6d5a1d80dd813a513e7e80d91f8b47f49b91cff67266b76f1d6275a7fea0  config-motorola-rtwo.aarch64
-ca36b981736b94d93120bea60d84614a5f943b0577a87ce0c650a7c065dc8b8b889eeee766b8fb941e15af4db5d426583d2d85e3e243faf89aa9cac472f78388  rtwo.config
+53441c23146d76bb0eaa358a25f6cce4f21740cfb65b755df52bbb218daf2cda30b3d80fa6ca4e283ea1afe2b0fa708307b678b421898100710b8fb99b08d6c5  rtwo.config
 e1633eb9a356de1e46c430fe2eb2c5d77ddeb9301f8cf9c95df3ae180d581a57ede0906aeddc0bcc15b95931c0dd40565930a1e1b72bfb540e5a99bcb9865e58  sm8550-motorola-rtwo.dts
 "

device/testing/linux-postmarketos-qcom-sm8550/rtwo.config

@@ -30,8 +30,8 @@ CONFIG_MAGIC_SYSRQ=y
 CONFIG_LOG_BUF_SHIFT=18
 
 # --- kernel image format ----------------------------------------------
-# The Motorola bootloader executes a plain gzip'd Image from the Android
+# The Motorola bootloader executes a raw uncompressed arm64 Image from the
-# boot.img; the EFI ZBOOT self-decompressor makes it reboot instantly.
+# Android boot.img; EFI ZBOOT self-decompression makes it reboot instantly.
 # CONFIG_EFI_ZBOOT is not set
 
 # --- build size / speed: device kernel, not the generic arm64 one ------