I see some references to bootm, kernel.img and dtb.img in fw_printenv, so tweaking with that may pave the way to booting Armbian properly. However I'm afraid to brick the device in the process. I vaguely remember that it's possible to backup the bootloader, but don't have any experience. Any pointers? Here's the full fw_printenv: EnableSelinux=enforcing Irq_check_en=0 active_slot=normal baudrate=115200 bcb_cmd=get_avb_mode;get_valid_slot; boot_part=boot bootcmd=run osmcfromsd; run osmcfromusb; run storeboot bootdelay=1 cmdline_keys=if keyman init 0x1234; then if keyman read mac ${loadaddr} str; then setenv bootargs ${bootargs} mac=${mac};fi;fi; colorattribute=444,8bit cvbs_drv=0 cvbsmode=576cvbs display_bpp=16 display_color_bg=0 display_color_fg=0xffff display_color_index=16 display_height=1080 display_layer=osd0 display_width=1920 dtb_mem_addr=0x1000000 factory_reset_poweroff_protect=echo wipe_data=${wipe_data}; echo wipe_cache=${wipe_cache};if test ${wipe_data} = failed; then run init_display; run storeargs;if mmcinfo; then run recovery_from_sdcard;fi;if usb start 0; then run recovery_from_udisk;fi;run recovery_from_flash;fi; if test ${wipe_cache} = failed; then run init_display; run storeargs;if mmcinfo; then run recovery_from_sdcard;fi;if usb start 0; then run recovery_from_udisk;fi;run recovery_from_flash;fi; fb_addr=0x7f800000 fb_height=1080 fb_width=1920 fdt_high=0x20000000 firstboot=0 fs_type=rootfstype=ramfs gatewayip=10.18.9.1 hdmimode=1080p60hz hostname=arm_gxbb init_display=get_rebootmode;echo reboot_mode:::: ${reboot_mode};if test ${reboot_mode} = quiescent; then setenv reboot_mode_android quiescent;run storeargs;setenv bootargs ${bootargs} androidboot.quiescent=1;osd open;osd clear;else if test ${reboot_mode} = recovery_quiescent; then setenv reboot_mode_android quiescent;run storeargs;setenv bootargs ${bootargs} androidboot.quiescent=1;osd open;osd clear;else setenv reboot_mode_android normal;run storeargs;osd open;osd clear;imgread pic logo bootup $loadaddr;bmp display $bootup_offset;bmp scale; fi;fi; initargs=init=/init console=ttyS0,115200 no_console_suspend earlycon=aml_uart,0xc81004c0 ramoops.pstore_en=1 ramoops.record_size=0x8000 ramoops.console_size=0x4000 jtag=apao loadaddr=1080000 lock=10001000 netmask=255.255.255.0 osmcfromsd=if mmcinfo; then if fatload mmc 0 ${loadaddr} kernel.img; then run sddtb; setenv bootargs ${bootargs} osmc.bootsource=sd; bootm; fi; fi osmcfromusb=if usb start 0; then if fatload usb 0 ${loadaddr} kernel.img; then run usbdtb; setenv bootargs ${bootargs} osmc.bootsource=usb; bootm; fi; fi otg_device=1 outputmode=1080p60hz page_trace=on preboot=run bcb_cmd; run factory_reset_poweroff_protect;run upgrade_check;run init_display;run storeargs;run upgrade_key;bcb uboot-command;run switch_bootmode; reboot_mode=cold_boot reboot_mode_android=normal recovery_from_flash=get_valid_slot;echo active_slot: ${active_slot};if test ${active_slot} = normal; then setenv bootargs ${bootargs} ${fs_type} aml_dt=${aml_dt} recovery_part={recovery_part} recovery_offset={recovery_offset};if itest ${upgrade_step} == 3; then if ext4load mmc 1:2 ${dtb_mem_addr} /recovery/dtb.img; then echo cache dtb.img loaded; fi;if ext4load mmc 1:2 ${loadaddr} /recovery/recovery.img; then echo cache recovery.img loaded; bootm ${loadaddr}; fi;else fi;if imgread kernel ${recovery_part} ${loadaddr} ${recovery_offset}; then bootm ${loadaddr}; fi;else setenv bootargs ${bootargs} ${fs_type} aml_dt=${aml_dt} recovery_part=${boot_part} recovery_offset=${recovery_offset};if imgread kernel ${boot_part} ${loadaddr}; then bootm ${loadaddr}; fi;fi; recovery_from_sdcard=setenv bootargs ${bootargs} aml_dt=${aml_dt} recovery_part={recovery_part} recovery_offset={recovery_offset};if fatload mmc 0 ${loadaddr} aml_autoscript; then autoscr ${loadaddr}; fi;if fatload mmc 0 ${loadaddr} recovery.img; then if fatload mmc 0 ${dtb_mem_addr} dtb.img; then echo sd dtb.img loaded; fi;setenv bootargs ${bootargs} ${fs_type};bootm ${loadaddr};fi; recovery_from_udisk=setenv bootargs ${bootargs} aml_dt=${aml_dt} recovery_part={recovery_part} recovery_offset={recovery_offset};if fatload usb 0 ${loadaddr} aml_autoscript; then autoscr ${loadaddr}; fi;if fatload usb 0 ${loadaddr} recovery.img; then if fatload usb 0 ${dtb_mem_addr} dtb.img; then echo udisk dtb.img loaded; fi;setenv bootargs ${bootargs} ${fs_type};bootm ${loadaddr};fi; recovery_offset=0 recovery_part=recovery rpmb_state=0 sdc_burning=sdc_burn ${sdcburncfg} sdcburncfg=aml_sdc_burn.ini sddtb=if fatload mmc 0 ${dtb_mem_addr} dtb.img; then echo loaded DTB from SD; else store dtb read $dtb_mem_addr; fi sdr2hdr=0 stderr=serial stdin=serial stdout=serial storeargs=setenv bootargs ${initargs} otg_device=${otg_device} reboot_mode_android=${reboot_mode_android} androidboot.selinux=${EnableSelinux} logo=${display_layer},loaded,${fb_addr},${outputmode} maxcpus=${maxcpus} vout=${outputmode},enable hdmimode=${hdmimode} cvbsmode=${cvbsmode} hdmitx=${cecconfig},${colorattribute} cvbsdrv=${cvbs_drv} irq_check_en=${Irq_check_en} androidboot.firstboot=${firstboot} jtag=${jtag}; setenv bootargs ${bootargs} androidboot.veritymode=enforcing androidboot.hardware=amlogic;setenv bootargs ${bootargs} page_trace=${page_trace};setenv bootargs ${bootargs} androidboot.rpmb_state=${rpmb_state};run cmdline_keys; storeboot=if imgread kernel ${boot_part} ${loadaddr}; then bootm ${loadaddr}; fi;run storeargs; run update; switch_bootmode=get_rebootmode;if test ${reboot_mode} = factory_reset; then setenv reboot_mode_android normal;run storeargs;run recovery_from_flash;else if test ${reboot_mode} = update; then setenv reboot_mode_android normal;run storeargs;run update;else if test ${reboot_mode} = quiescent; then setenv reboot_mode_android quiescent;run storeargs;setenv bootargs ${bootargs} androidboot.quiescent=1;else if test ${reboot_mode} = recovery_quiescent; then setenv reboot_mode_android quiescent;run storeargs;setenv bootargs ${bootargs} androidboot.quiescent=1;run recovery_from_flash;else if test ${reboot_mode} = cold_boot; then setenv reboot_mode_android normal;run storeargs;else if test ${reboot_mode} = fastboot; then setenv reboot_mode_android normal;run storeargs;fastboot;fi;fi;fi;fi;fi;fi; try_auto_burn=update 700 750; update=run usb_burning; run sdc_burning; if mmcinfo; then run recovery_from_sdcard;fi;if usb start 0; then run recovery_from_udisk;fi;run recovery_from_flash; upgrade_check=echo upgrade_step=${upgrade_step}; if itest ${upgrade_step} == 3; then run init_display; run storeargs; run update;else fi; upgrade_key=if gpio input GPIOAO_2; then echo detect upgrade key; sleep 3;if gpio input GPIOAO_2; then run update; fi;fi; upgrade_step=2 usb_burning=update 1000 usbdtb=if fatload usb 0 ${dtb_mem_addr} dtb.img; then echo loaded DTB from usb; else store dtb read $dtb_mem_addr; fi v4kflash=verify wipe_cache=successful wipe_data=successful

I went the naive approach and just copied `Image` as `kernel.img` in the boot partition. The "Unable to read file kernel.img" went away and it said "** Unable to read file dtb.img **". So then I copied meson-gxl-s905x-vero4k.dtb to dtb.img. Now it logs the following: reading kernel.img 29127168 bytes read in 1578 ms (17.6 MiB/s) reading dtb.img 40983 bytes read in 5 ms (7.8 MiB/s) loaded DTB from SD avb2: 0 ee_gate_off ... avb2: 0 Wrong Image Format for bootm command ERROR: can't get kernel image! [rsvmem] get fdtaddr NULL! rsvmem - reserve memory I'm guessing the file format is not what it expects.

@helios4user12 > I updated the sd card with the provided image via dd. Will this be a one time thing? Yes. In the meantime there were further updates and my Helios4 is still going strong.

I reflashed Armbian on an SD card and booted while connected to UART. Then I inspected the difference between the boot logs. Below is the diff (right is with SD card). It looks like the SD card is recognized and an attempt at booting is made, but it's unable to read a kernel.img file. Any help is much appreciated <snip> Hit Enter or space or Ctrl+C key to stop autoboot -- : 0 │ Hit Enter or space or Ctrl+C key to stop autoboot -- : 0 card out │ card in co-phase 0x2, tx-dly 0, clock 400000 │ co-phase 0x2, tx-dly 0, clock 400000 co-phase 0x2, tx-dly 0, clock 400000 │ co-phase 0x2, tx-dly 0, clock 400000 co-phase 0x2, tx-dly 0, clock 400000 │ co-phase 0x2, tx-dly 0, clock 400000 emmc/sd response timeout, cmd8, status=0x1ff2800 │ co-phase 0x2, tx-dly 0, clock 400000 emmc/sd response timeout, cmd55, status=0x1ff2800 │ co-phase 0x2, tx-dly 0, clock 40000000 emmc/sd response timeout, cmd1, status=0x1ff2800 │ [mmc_startup] mmc refix success ------------------------------------------------------------------│ init_part() 282: PART_TYPE_DOS ------------------------------------------------------------------│ [mmc_init] mmc init success ------------------------------------------------------------------│ Device: SDIO Port B ------------------------------------------------------------------│ Manufacturer ID: 27 ------------------------------------------------------------------│ OEM: 5048 ------------------------------------------------------------------│ Name: SD64G ------------------------------------------------------------------│ Tran Speed: 50000000 ------------------------------------------------------------------│ Rd Block Len: 512 ------------------------------------------------------------------│ SD version 3.0 ------------------------------------------------------------------│ High Capacity: Yes ------------------------------------------------------------------│ Capacity: 58.2 GiB ------------------------------------------------------------------│ mmc clock: 40000000 ------------------------------------------------------------------│ Bus Width: 4-bit ------------------------------------------------------------------│ reading kernel.img ------------------------------------------------------------------│ ** Unable to read file kernel.img ** <snip> │ Starting kernel ... │ Starting kernel ... │ <snip> - page_trace_module_init, create sysfs failed │ - page_trace_module_init, create sysfs failed ------------------------------------------------------------------│ - meson-mmc: card IN - spdif-dit spdif_codec: audio_spdif_out_mute can't get pinctrl │ - spdif-dit spdif_codec: audio_spdif_out_mute can't get pinctrl <snip until kernel boot is finished>

Ooh okay, I see now. Thanks again!