further work in progress

board/raspberrypi3_swupdate/cmdline.txt

@@ -1 +1 @@
-console=ttyS0,115200 rootwait
+console=ttyAMA1,115200 rootwait

board/raspberrypi3_swupdate/config.txt

@@ -3,9 +3,8 @@ arm_64bit=1
 
 # configure the uart
 enable_uart=1
+dtoverlay=disable-bt
 core_freq=250
-init_uart_clock=48000000
-init_uart_baud=115200
 uart_2ndstage=1
 
 # Disable HDMI to reduce noise
@@ -19,6 +18,7 @@ gpu_mem=32
 # start the bootloader which then selects system A or B
 kernel=u-boot.bin
 
-# dt overlays
+# dt overlays Note: dt overlays must also be added in genimage-raspberrypi3_swupdate.cfg
+dtdebug=1
 dtoverlay=disable-bt
 #dtoverlay=disable-wifi

board/raspberrypi3_swupdate/disable-ftrace.fragment

@@ -0,0 +1,8 @@
+# Disable kernel tracing and function tracing to avoid boot panic on RPi3 aarch64
+CONFIG_FTRACE=n
+CONFIG_FUNCTION_TRACER=n
+CONFIG_DYNAMIC_FTRACE=n
+CONFIG_FUNCTION_GRAPH_TRACER=n
+CONFIG_STACK_TRACER=n
+CONFIG_BRANCH_PROFILE_NONE=n
+CONFIG_KPROBES=n

board/raspberrypi3_swupdate/genimage-raspberrypi3_swupdate.cfg

@@ -14,8 +14,8 @@ image boot.vfat {
     file uboot.env {
       image = "uboot-env.img"
     }
-    file overlays/README {
-      image = "rpi-firmware/overlays/README"
+    file overlays/disable-bt.dtbo {
+      image = "rpi-firmware/overlays/disable-bt.dtbo"
     }
     file bootcode.bin {
       image = "rpi-firmware/bootcode.bin"

board/raspberrypi3_swupdate/rootfs_overlay/etc/systemd/system/getty.target.wants/getty@ttyAMA1.service

@@ -0,0 +1 @@
+/lib/systemd/system/getty@.service

board/raspberrypi3_swupdate/uboot-env.txt

@@ -2,38 +2,16 @@
 # Default variables for first boot - these will be modified during operation
 
 # Active partition (A or B)
-kernel_addr_r=0x01000000
-fdt_addr_r=0x03000000
-active_part=A
-active_root=/dev/mmcblk0p2
-inactive_part=B
-inactive_root=/dev/mmcblk0p3
-
-# Boot attempt counters
-bootcount=0
-bootlimit=3
-
-# Default bootcmd
-bootcmd=run bootcmd_${active_part}
-
-# Kernel boot arguments
-bootargs=console=ttyS0,115200 root=${active_root} rootwait
-
-# Commands for booting from A or B partitions
-bootcmd_A=setenv bootargs console=ttyS0,115200 root=/dev/mmcblk0p2 rootwait; load mmc 0:1 ${kernel_addr_r} Image; load mmc 0:1 0x03000000 bcm2710-rpi-3-b.dtb; booti ${kernel_addr_r} - 0x03000000
-bootcmd_B=setenv bootargs console=ttyS0,115200 root=/dev/mmcblk0p3 rootwait; load mmc 0:1 ${kernel_addr_r} Image; load mmc 0:1 0x03000000 bcm2710-rpi-3-b.dtb; booti ${kernel_addr_r} - 0x03000000
-
-# Fallback logic for failed boots
-altbootcmd=if test ${active_part} = A; then setenv active_part B; setenv active_root /dev/mmcblk0p3; setenv inactive_part A; setenv inactive_root /dev/mmcblk0p2; else setenv active_part A; setenv active_root /dev/mmcblk0p2; setenv inactive_part B; setenv inactive_root /dev/mmcblk0p3; fi; setenv bootcount 0; saveenv; run bootcmd
 
 # Memory addresses
 kernel_addr_r=0x01000000
-fdt_addr_r=0x02000000
+fdt_addr_r=0x03000000
 
-# Board name
-board_name=rpi3
+# Always boot partition A using PL011 UART for console and earlycon
+bootcmd=setenv bootargs console=ttyAMA1,115200 earlycon=pl011,0x3f201000,115200 root=/dev/mmcblk0p2 rootwait net.ifnames=0; \
+         load mmc 0:1 ${kernel_addr_r} Image; \
+         load mmc 0:1 ${fdt_addr_r} bcm2710-rpi-3-b.dtb; \
+         booti ${kernel_addr_r} - ${fdt_addr_r}
 
-# Network configuration (DHCP)
-autoload=no
-ethact=smi
-ethaddr_sdio0=00:44:55:66:77:88
+# No network, no A/B switching, no fallback logic
+# Only the essential commands are included for clarity