wb7, wb8: pstore/ramoops panic-log persistence (shuttle kernel side)

arch/arm/boot/dts/allwinner/sun8i-r40-wirenboard72x.dtsi

@@ -38,6 +38,34 @@
 		stdout-path = "serial0:115200n8";
 	};
 
+	/* Fixed-address pstore/ramoops region; survives a warm reset so the
+	 * same kernel can harvest it even under an old U-Boot with no shuttle.
+	 * The base MUST match U-Boot WB_RAMOOPS_BASE (0x43800000).
+	 *
+	 * The address was chosen for the arm64/H616 boot map but is reused
+	 * here for R40. On R40 it clears the used load addresses (fdt
+	 * 0x43000000, overlay 0x43300000) and sits ~4 MiB above the stock
+	 * RAMDISK_ADDR_R (0x43400000). WB firmware boots without an initrd
+	 * (bootz "... - ..."), so ramdisk_addr_r is unused; if that ever
+	 * changes, an initrd >4 MiB would overlap this region. There is no
+	 * build-time guard on the R40 side (the U-Boot static_asserts are
+	 * WB8-only). Pending: retention validation on real WB7 hardware.
+	 */
+	reserved-memory {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+
+		ramoops@43800000 {
+			compatible = "ramoops";
+			reg = <0x43800000 0x100000>;
+			record-size = <0x20000>;
+			console-size = <0x40000>;
+			ecc-size = <32>;
+			no-map;
+		};
+	};
+
 	regulators {
 		compatible = "simple-bus";
 		#address-cells = <1>;

arch/arm/boot/dts/allwinner/sun8i-r40-wirenboard74x.dtsi

@@ -40,6 +40,34 @@
 		stdout-path = "serial0:115200n8";
 	};
 
+	/* Fixed-address pstore/ramoops region; survives a warm reset so the
+	 * same kernel can harvest it even under an old U-Boot with no shuttle.
+	 * The base MUST match U-Boot WB_RAMOOPS_BASE (0x43800000).
+	 *
+	 * The address was chosen for the arm64/H616 boot map but is reused
+	 * here for R40. On R40 it clears the used load addresses (fdt
+	 * 0x43000000, overlay 0x43300000) and sits ~4 MiB above the stock
+	 * RAMDISK_ADDR_R (0x43400000). WB firmware boots without an initrd
+	 * (bootz "... - ..."), so ramdisk_addr_r is unused; if that ever
+	 * changes, an initrd >4 MiB would overlap this region. There is no
+	 * build-time guard on the R40 side (the U-Boot static_asserts are
+	 * WB8-only). Pending: retention validation on real WB7 hardware.
+	 */
+	reserved-memory {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+
+		ramoops@43800000 {
+			compatible = "ramoops";
+			reg = <0x43800000 0x100000>;
+			record-size = <0x20000>;
+			console-size = <0x40000>;
+			ecc-size = <32>;
+			no-map;
+		};
+	};
+
 	regulators {
 		compatible = "simple-bus";
 		#address-cells = <1>;

arch/arm/configs/wirenboard7_defconfig

@@ -591,3 +591,12 @@ CONFIG_PREEMPTIRQ_DELAY_TEST=m
 CONFIG_STRICT_DEVMEM=y
 CONFIG_DEBUG_USER=y
 CONFIG_CONFIGFS_FS=y
+
+# Pstore/ramoops: persist kernel panic + console logs in a RAM region
+# across warm resets. The reserved-memory "ramoops" node is injected by
+# the Wiren Board U-Boot DT fixup (WIRENBOARD_RAMOOPS_FIXUP); without it
+# these options are inert. PSTORE_RAM auto-selects REED_SOLOMON*.
+CONFIG_PSTORE=y
+CONFIG_PSTORE_RAM=y
+CONFIG_PSTORE_CONSOLE=y
+CONFIG_WB_RAMOOPS_PANIC_RESET=y

arch/arm64/boot/dts/allwinner/sun50i-h616-wirenboard84x.dtsi

@@ -48,6 +48,25 @@
 		rtc_onboard = &rtc_onboard;
 	};
 
+	/* Fixed-address pstore/ramoops region; survives a warm reset so the
+	 * same kernel can harvest it even under an old U-Boot with no shuttle.
+	 * The base MUST match U-Boot WB_RAMOOPS_BASE (0x43800000).
+	 */
+	reserved-memory {
+		#address-cells = <2>;
+		#size-cells = <2>;
+		ranges;
+
+		ramoops@43800000 {
+			compatible = "ramoops";
+			reg = <0x0 0x43800000 0x0 0x100000>;
+			record-size = <0x20000>;
+			console-size = <0x40000>;
+			ecc-size = <32>;
+			no-map;
+		};
+	};
+
 	wirenboard {
 		adc-type = <3>;
 		pwm-buzzer = <1>;

arch/arm64/boot/dts/allwinner/sun50i-h616-wirenboard85x.dtsi

@@ -404,6 +404,21 @@
 			alloc-ranges = <0x0 0x00000000 0x0 0x80000000>;
 			linux,cma-default;
 		};
+
+		/* Fixed-address pstore/ramoops region; survives a warm reset so
+		 * the same kernel can harvest it even under an old U-Boot with no
+		 * shuttle. The base MUST match U-Boot WB_RAMOOPS_BASE (0x43800000).
+		 * #address-cells/#size-cells/ranges (2/2) are inherited from the
+		 * /reserved-memory node in sun50i-h616.dtsi that this merges into.
+		 */
+		ramoops@43800000 {
+			compatible = "ramoops";
+			reg = <0x0 0x43800000 0x0 0x100000>;
+			record-size = <0x20000>;
+			console-size = <0x40000>;
+			ecc-size = <32>;
+			no-map;
+		};
 	};
 
 	soc {

arch/arm64/configs/wb8.config

@@ -382,3 +382,12 @@ CONFIG_SUN50I_H6_PRCM_PPU=y
 
 #SOUND
 CONFIG_SND_HDA_PREALLOC_SIZE=2048
+
+# Pstore/ramoops: persist kernel panic + console logs in a RAM region
+# across warm resets. The reserved-memory "ramoops" node is injected by
+# the Wiren Board U-Boot DT fixup (WIRENBOARD_RAMOOPS_FIXUP); without it
+# these options are inert. PSTORE_RAM auto-selects REED_SOLOMON*.
+CONFIG_PSTORE=y
+CONFIG_PSTORE_RAM=y
+CONFIG_PSTORE_CONSOLE=y
+CONFIG_WB_RAMOOPS_PANIC_RESET=y

drivers/mfd/wbec.c

@@ -25,14 +25,21 @@
 /* For power off WBEC activates PWON pin on PMIC for 6s */
 #define WBEC_POWER_RESET_DELAY_MS			10000
 
+/*
+ * Mirrors LINUX_POWERON_REASON in wb-embedded-controller src/wbec.c;
+ * append-only ABI.
+ */
 static const char * const wbec_poweron_reason[] = {
-	"Power supply on",
-	"Power button",
-	"RTC alarm",
-	"Reboot",
-	"Reboot instead of poweroff",
-	"Watchdog",
-	"PMIC is unexpectedly off",
+	[0] = "Power supply on",
+	[1] = "Power button",
+	[2] = "RTC alarm",
+	[3] = "Reboot",
+	[4] = "Reboot instead of poweroff",
+	[5] = "Watchdog",
+	[6] = "PMIC is unexpectedly off",
+	[7] = "Unknown",
+	[8] = "Watchdog (warm reset)",
+	[9] = "Full power cycle request",
 };
 
 static const struct regmap_config wbec_regmap_config_v1 = {

drivers/soc/sunxi/Kconfig

@@ -19,3 +19,14 @@ config SUNXI_SRAM
 	  Say y here to enable the SRAM controller support. This
 	  device is responsible on mapping the SRAM in the sunXi SoCs
 	  whether to the CPU/DMA, or to the devices.
+
+config WB_RAMOOPS_PANIC_RESET
+	bool "Wiren Board: SoC watchdog warm reset on panic when ramoops is present"
+	depends on ARCH_SUNXI && PSTORE_RAM
+	help
+	  On panic, arm the (otherwise idle) SoC watchdog so a Wiren
+	  Board 7 (Allwinner R40/A40i) or Wiren Board 8 (Allwinner
+	  T507/H616) takes a DRAM-preserving warm reset and the panic
+	  log survives in the ramoops region for the bootloader to
+	  persist. Arms itself only when a ramoops reserved-memory
+	  node is present.

drivers/soc/sunxi/Makefile

@@ -1,3 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_SUNXI_MBUS) +=	sunxi_mbus.o
 obj-$(CONFIG_SUNXI_SRAM) +=	sunxi_sram.o
+obj-$(CONFIG_WB_RAMOOPS_PANIC_RESET) +=	wb-ramoops-panic-reset.o