From aaa55848de556d63b8efa6e6ca940ecac827a07f Mon Sep 17 00:00:00 2001
From: Stefan Agner <stefan@agner.ch>
Date: Wed, 23 Mar 2022 16:00:49 +0100
Subject: [PATCH] Implement A/B switch when moving back to Barebox (#1794)

* Implement manual boot switch when downgrading to Barebox

When installing OS 7 or older from a OS 8 installation, the bootloader
is changed back to Barebox. However, in this case Barebox does not know
which boot slot is correct (and rauc won't update Barebox' state as it
is configured to work with GRUB in OS 8+).

This implements a poor mans version to switch the boot partition. It
clears Barebox state and deploys one of the two pre-configured default
states, booting either boot slot A or B.
---
 .../board/pc/generic-x86-64/hassos-hook.sh    |   2 +
 .../board/pc/ova/hassos-hook.sh               |   2 +
 .../bootloader/barebox-state-efi-A.dtb        | Bin 0 -> 1147 bytes
 .../bootloader/barebox-state-efi-A.dts        |  76 ++++++++++++++++++
 .../bootloader/barebox-state-efi-B.dtb        | Bin 0 -> 1147 bytes
 .../bootloader/barebox-state-efi-B.dts        |  76 ++++++++++++++++++
 buildroot-external/ota/rauc-hook              |  19 +++++
 buildroot-external/scripts/ota.sh             |   3 +
 8 files changed, 178 insertions(+)
 create mode 100644 buildroot-external/bootloader/barebox-state-efi-A.dtb
 create mode 100644 buildroot-external/bootloader/barebox-state-efi-A.dts
 create mode 100644 buildroot-external/bootloader/barebox-state-efi-B.dtb
 create mode 100644 buildroot-external/bootloader/barebox-state-efi-B.dts

diff --git a/buildroot-external/board/pc/generic-x86-64/hassos-hook.sh b/buildroot-external/board/pc/generic-x86-64/hassos-hook.sh
index f64466167..dfac639ae 100755
--- a/buildroot-external/board/pc/generic-x86-64/hassos-hook.sh
+++ b/buildroot-external/board/pc/generic-x86-64/hassos-hook.sh
@@ -9,6 +9,8 @@ function hassos_pre_image() {
 
     cp "${BINARIES_DIR}/barebox.bin" "${BOOT_DATA}/EFI/BOOT/BOOTx64.EFI"
     cp "${BR2_EXTERNAL_HASSOS_PATH}/bootloader/barebox-state-efi.dtb" "${BOOT_DATA}/EFI/barebox/state.dtb"
+    cp "${BR2_EXTERNAL_HASSOS_PATH}/bootloader/barebox-state-efi-A.dtb" "${BOOT_DATA}/EFI/barebox/state-A.dtb"
+    cp "${BR2_EXTERNAL_HASSOS_PATH}/bootloader/barebox-state-efi-B.dtb" "${BOOT_DATA}/EFI/barebox/state-B.dtb"
     cp "${BOARD_DIR}/cmdline.txt" "${BOOT_DATA}/cmdline.txt"
 }
 
diff --git a/buildroot-external/board/pc/ova/hassos-hook.sh b/buildroot-external/board/pc/ova/hassos-hook.sh
index 4f2278a9c..afc9d4cfb 100755
--- a/buildroot-external/board/pc/ova/hassos-hook.sh
+++ b/buildroot-external/board/pc/ova/hassos-hook.sh
@@ -9,6 +9,8 @@ function hassos_pre_image() {
 
     cp "${BINARIES_DIR}/barebox.bin" "${BOOT_DATA}/EFI/BOOT/BOOTx64.EFI"
     cp "${BR2_EXTERNAL_HASSOS_PATH}/bootloader/barebox-state-efi.dtb" "${BOOT_DATA}/EFI/barebox/state.dtb"
+    cp "${BR2_EXTERNAL_HASSOS_PATH}/bootloader/barebox-state-efi-A.dtb" "${BOOT_DATA}/EFI/barebox/state-A.dtb"
+    cp "${BR2_EXTERNAL_HASSOS_PATH}/bootloader/barebox-state-efi-B.dtb" "${BOOT_DATA}/EFI/barebox/state-B.dtb"
     cp "${BOARD_DIR}/cmdline.txt" "${BOOT_DATA}/cmdline.txt"
 }
 
diff --git a/buildroot-external/bootloader/barebox-state-efi-A.dtb b/buildroot-external/bootloader/barebox-state-efi-A.dtb
new file mode 100644
index 0000000000000000000000000000000000000000..e26c070714a446904e51d9cf72f056b5e7ffd62e
GIT binary patch
literal 1147
zcmb7D+invv5S`EpD1u%j_<*XQ^1!N_-Ly2kG|dbDzypzY?M*E9CfiXj{0JY#Lw}^|
zA0X!JEhID|Send?GjsOLv3>XI*FDkpcOp7xzs>$V+X34?8`c%k*3UXz`t3DYPo!E{
zWsz>NJwtF}op1^fJz?uD(y9jEd5V2D^dNt;k{>?&7+*C1@3KFRgi%p({oxU;V5Rqy
z5lnl5{h4U*4mD9xxJUZeap_$GWr4G{&Ztc2T<6n?a86~Vvm?K5t>$~q@s}pYtgTMt
zxz1e(_KR<PZQ@F|(&)lycQYDvH7yo!Ho<z$b-=3d#uZGb`Txwr_oG_i-g1E7gaaCv
z=ZUekq|HmtH^F+rb=^Fvux=913aj!_zgGNDez?QyFguJ)#50|%iI$^&E%OpD==YYb
zJ2UGHA2jdOd$_|mGpr7?6vk<%i@bUk|I{1Ucyq^zzE;v(>HhouyyMy=41@6Ov_JGd
zCSl+WWRiI2z8`pDIP{~lAP)VZ<T@<iLx+M5d|RIIJN0`w5>gsvtrx2_wRB|lt!m;-
yOm$3gk(I*fC{+}R_?yaQ>pgc<cAFmLkqYf()Rd%3#5{F`ndWmXsho*iGRSWyOOxCH

literal 0
HcmV?d00001

diff --git a/buildroot-external/bootloader/barebox-state-efi-A.dts b/buildroot-external/bootloader/barebox-state-efi-A.dts
new file mode 100644
index 000000000..8d2705f8e
--- /dev/null
+++ b/buildroot-external/bootloader/barebox-state-efi-A.dts
@@ -0,0 +1,76 @@
+/dts-v1/;
+/ {
+
+	aliases {
+		state = &state;
+	};
+
+	state: state {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		
+		magic = <0xef98423f>;
+		compatible = "barebox,state";
+		backend = <&backend_state>;
+		backend-type = "raw";
+		backend-stridesize = <4048>;
+
+		bootstate {
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			A {
+				#address-cells = <1>;
+				#size-cells = <1>;
+				remaining_attempts@0 {
+					reg = <0x0 0x4>;
+					type = "uint32";
+					default = <3>;
+				};
+				priority@4 {
+					reg = <0x4 0x4>;
+					type = "uint32";
+					default = <20>;
+				};
+			};
+
+			B {
+				#address-cells = <1>;
+				#size-cells = <1>;
+				remaining_attempts@8 {
+					reg = <0x8 0x4>;
+					type = "uint32";
+					default = <0>;
+				};
+				priority@c {
+					reg = <0xc 0x4>;
+					type = "uint32";
+					default = <10>;
+				};
+			};
+
+			last_chosen@10 {
+				reg = <0x10 0x4>;
+				type = "uint32";
+			};
+		};
+
+		machine_id@14 {
+			reg = <0x14 0x24>;
+			type = "string";
+			default = "";
+		};
+	};
+
+	partitions {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		compatible = "fixed-partitions";
+
+		backend_state: state {
+			partuuid = "33236519-7f32-4dff-8002-3390b62c309d";
+		};
+	};
+
+};
+
diff --git a/buildroot-external/bootloader/barebox-state-efi-B.dtb b/buildroot-external/bootloader/barebox-state-efi-B.dtb
new file mode 100644
index 0000000000000000000000000000000000000000..8b96079bdb01be3a8fbdfaccdae36220a0010155
GIT binary patch
literal 1147
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z?)Jz!!w1b)Glx5jGsBoOYhj#rx+?v%xVPV6<IU}5`c%naCHwaK`N*+Z97pltL4Ob&
zWpNbj%Pb3y!!Qcscn~IsQ5uH>$#EFqqYo7e>h0=;e%8E)T_L4W)&{A{b4$BcpR3j`
z#6+i*Rz)qGPI5(wNPnwRb~<op^?Wiwd!#}-88soPGBL{?VNbJ}mQ+tgDH-w)C1;c0

literal 0
HcmV?d00001

diff --git a/buildroot-external/bootloader/barebox-state-efi-B.dts b/buildroot-external/bootloader/barebox-state-efi-B.dts
new file mode 100644
index 000000000..d861a9488
--- /dev/null
+++ b/buildroot-external/bootloader/barebox-state-efi-B.dts
@@ -0,0 +1,76 @@
+/dts-v1/;
+/ {
+
+	aliases {
+		state = &state;
+	};
+
+	state: state {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		
+		magic = <0xef98423f>;
+		compatible = "barebox,state";
+		backend = <&backend_state>;
+		backend-type = "raw";
+		backend-stridesize = <4048>;
+
+		bootstate {
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			A {
+				#address-cells = <1>;
+				#size-cells = <1>;
+				remaining_attempts@0 {
+					reg = <0x0 0x4>;
+					type = "uint32";
+					default = <3>;
+				};
+				priority@4 {
+					reg = <0x4 0x4>;
+					type = "uint32";
+					default = <10>;
+				};
+			};
+
+			B {
+				#address-cells = <1>;
+				#size-cells = <1>;
+				remaining_attempts@8 {
+					reg = <0x8 0x4>;
+					type = "uint32";
+					default = <3>;
+				};
+				priority@c {
+					reg = <0xc 0x4>;
+					type = "uint32";
+					default = <20>;
+				};
+			};
+
+			last_chosen@10 {
+				reg = <0x10 0x4>;
+				type = "uint32";
+			};
+		};
+
+		machine_id@14 {
+			reg = <0x14 0x24>;
+			type = "string";
+			default = "";
+		};
+	};
+
+	partitions {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		compatible = "fixed-partitions";
+
+		backend_state: state {
+			partuuid = "33236519-7f32-4dff-8002-3390b62c309d";
+		};
+	};
+
+};
+
diff --git a/buildroot-external/ota/rauc-hook b/buildroot-external/ota/rauc-hook
index 9c2ef3c56..d3133cf7c 100755
--- a/buildroot-external/ota/rauc-hook
+++ b/buildroot-external/ota/rauc-hook
@@ -28,6 +28,25 @@ case "$1" in
     slot-install)
         # Use install handlers below
         ;;
+    slot-post-install)
+        # Handle main slot only
+        test "${RAUC_SLOT_CLASS}" = "kernel" || exit 0
+
+        BOOT_MNT=/mnt/boot
+
+        if ! systemctl -q is-active mnt-boot.mount; then
+            systemctl start mnt-boot.mount
+        fi
+
+        # OS 8+ to 7 and lower downgrade path
+        if ! command -v barebox-state > /dev/null; then
+            cp -f "${BOOT_MNT}/EFI/barebox/state-${RAUC_SLOT_BOOTNAME}.dtb" "${BOOT_MNT}"/EFI/barebox/state.dtb
+            blkdiscard /dev/disk/by-partuuid/33236519-7f32-4dff-8002-3390b62c309d
+            echo "Cleared state and copied default state-${RAUC_SLOT_BOOTNAME}.dtb to state.dtb."
+        fi
+
+        exit 0
+        ;;
     *)
         exit 1
         ;;
diff --git a/buildroot-external/scripts/ota.sh b/buildroot-external/scripts/ota.sh
index 918a5f8ee..87ed5f2a5 100755
--- a/buildroot-external/scripts/ota.sh
+++ b/buildroot-external/scripts/ota.sh
@@ -38,6 +38,9 @@ function create_ota_update() {
         echo "hooks=install"
         echo "[image.kernel]"
         echo "filename=kernel.img"
+        if [ "${BOOTLOADER}" == "barebox" ]; then
+            echo "hooks=post-install"
+        fi
         echo "[image.rootfs]"
         echo "filename=rootfs.img"
     ) > "${rauc_folder}/manifest.raucm"