OpenWrt installed MikroTik RB750Gr3 won't boot when WAN cable plugged

alfa · December 23, 2022, 2:15pm

Hi,
I installed OpenWRT 21.02.3 on rb750gr3
and i am having weird issues when i plug a cable to WAN port
and then power up the device . Power and USR LED's light is constantly on and the WAN LED keeps flashing. But when i unplug and reboot or boot the device without plugging in any cable it successfully boots.

i have no idea why this occurs like that.
Any help would be appreciated.
Thanks..

DISTRIB_ID='OpenWrt'
DISTRIB_RELEASE='21.02.3'
DISTRIB_REVISION='r16554-1d4dea6d4f'
DISTRIB_TARGET='ramips/mt7621'
DISTRIB_ARCH='mipsel_24kc'
DISTRIB_DESCRIPTION='OpenWrt 21.02.3 r16554-1d4dea6d4f'
DISTRIB_TAINTS='no-all busybox'


~# cat /proc/mtd 
dev:    size   erasesize  name
mtd0: 00040000 00010000 "RouterBoot"
mtd1: 0000f000 00010000 "bootloader1"
mtd2: 00001000 00010000 "hard_config"
mtd3: 0000f000 00010000 "bootloader2"
mtd4: 00001000 00010000 "soft_config"
mtd5: 00001000 00010000 "bios"
mtd6: 00fc0000 00010000 "firmware"
mtd7: 00270000 00010000 "kernel"
mtd8: 00d50000 00010000 "rootfs"
mtd9: 00ae0000 00010000 "rootfs_data"

Linux alfa 5.4.188 #0 SMP Sat Apr 16 12:59:34 2022 mips GNU/Linux

frollic · December 23, 2022, 3:19pm

Start by upgrading ?

johnth · December 23, 2022, 8:56pm

To help check if the bootloader is getting stuck, could you provide the output of:

for i in /sys/firmware/mikrotik/soft_config/*; do echo -n "$(basename $i): "; cat $i; done

Also worth running tcpdump on a device upstream of 750 WAN to try to see what is happening.

lleachii · December 24, 2022, 5:31am

Do you have a LAN cable plugged in?

alfa · December 24, 2022, 6:11am

Thanks for your interest here is output:

~# for i in /sys/firmware/mikrotik/soft_config/*; do echo -n "$(basename $i): "; cat $i; done
bios_version: 6.48.6
boot_delay: 1 [2] 3 4 5 6 7 8 9 
boot_device: eth flasheth ethonce flash [cfg] cfgonce 
boot_key: [any] del
boot_proto: [bootp] dhcp
booter: [regular] backup
cpu_mode: [powersave] regular
cpufreq_index: 0x00000370
silent_boot: [off] on
uart_speed: off 1200 2400 4800 9600 19200 38400 57600 [115200]

alfa · December 24, 2022, 6:15am

Plugged LAN Cable didn't cause booting problem.

lleachii · December 24, 2022, 8:13am

I would suggest that. Some devices have a PoE circuit breaker. I'm not sure about your specific device; but this may be the issue.

johnth · December 24, 2022, 8:39am

that is your issue. bootloader is set to autoconfigure mode
try

echo "flasheth">/sys/firmware/mikrotik/soft_config/boot_device
echo "y">/sys/firmware/mikrotik/soft_config/commit

If that does not change it, you will need to do the hold-in-reset-button to reset config as documented by Mikrotik. That resets RouterBOOT to default config

alfa · December 24, 2022, 8:44am

I compared 2 devices with dfiiferent serial numbers
Device with serial CC boots without any problem when wan cable plug
but device with HC serial not booted

and
I have set up dhcp server and found that HC is creating BOOTP request when i powered up the device the other is not .

also there is different boot_device configurations in soft_configs

boot_device: eth [flasheth] ethonce flash cfg cfgonce 

boot_device: eth flasheth ethonce flash [cfg] cfgonce

how can i set soft_config parameters

echo flasheth > /sys/firmware/mikrotik/soft_config/boot_device
echo 1 > /sys/firmware/mikrotik/soft_config/commit

##### WHEN I PLUG WAN CABLE DEVICE WITH board_serial: CCxxxxxxxx BOOTED  WITHOUT ANY ISSUES   #####

board_identifier: 750g-mt
board_product_code: RB750Gr3
board_revision: r4
board_serial: CCxxxxxxxx
booter_version: 6.48.6
flash_info: 0x001870ef
0x0000000c
0x00001000
0x00000000
0x00000000
hw_options: raw		: 0x084a4007

no UART		: true
has Vreg	: true
has usb		: true
has ATtiny	: false
no NAND		: true
has LCD		: false
has POE out	: false
has MicroSD	: true
has SIM		: false
has SFP		: false
has WiFi	: false
has TS ADC	: true
has PLC		: false
mac_base: dc:2c:6e:xx:xx:xx
mac_count: 0x00000005
mem_size: 0x10000000
product_name: hEX
wlan_data: 

for i in /sys/firmware/mikrotik/soft_config/*; do echo -n "$(basename $i): "; cat $i; 
done
bios_version: 6.48.6
boot_delay: 1 [2] 3 4 5 6 7 8 9 
boot_device: eth [flasheth] ethonce flash cfg cfgonce 
boot_key: [any] del
boot_proto: [bootp] dhcp
booter: [regular] backup
cpu_mode: [powersave] regular
cpufreq_index: 0x00000370
silent_boot: [off] on
uart_speed: off 1200 2400 4800 9600 19200 38400 57600 [115200] 


### DHCP SERVER LOGS

 ~/tftp % sudo ./loader.sh
dnsmasq: started, version 2.86 DNS disabled
dnsmasq: compile time options: IPv6 GNU-getopt DBus no-UBus i18n IDN2 DHCP DHCPv6 no-Lua TFTP conntrack ipset auth cryptohash DNSSEC loop-detect inotify dumpfile
dnsmasq-dhcp: DHCP, IP range 192.168.1.100 -- 192.168.1.120, lease time 1h
dnsmasq-dhcp: DHCPDISCOVER(enp2s0) 00:ab:ad:xx:xx:xx
dnsmasq-dhcp: DHCPOFFER(enp2s0) 192.168.1.110 00:ab:ad:xx:xx:xx
dnsmasq-dhcp: DHCPREQUEST(enp2s0) 192.168.1.110 00:ab:ad:xx:xx:xx
dnsmasq-dhcp: DHCPACK(enp2s0) 192.168.1.110 00:ab:ad:xx:xx:xx test

#########################################################################################################

##### WHEN I PLUG WAN CABLE DEVICE WITH board_serial: HCxxxxxxxx  DOESN'T BOOT   #####

board_identifier: 750g-mt
board_product_code: RB750Gr3
board_revision: r4
board_serial: HCxxxxxxxx
booter_version: 6.48.6
flash_info: 0x001870ef
0x0000000c
0x00001000
0x00000000
0x00000000
hw_options: raw		: 0x084a4007

no UART		: true
has Vreg	: true
has usb		: true
has ATtiny	: false
no NAND		: true
has LCD		: false
has POE out	: false
has MicroSD	: true
has SIM		: false
has SFP		: false
has WiFi	: false
has TS ADC	: true
has PLC		: false
mac_base: 18:fd:74:xx:xx:xx
mac_count: 0x00000005
mem_size: 0x10000000
product_name: hEX
wlan_data:

~# for i in /sys/firmware/mikrotik/soft_config/*; do echo -n "$(basename $i): "; cat $i; done
bios_version: 6.48.6
boot_delay: 1 [2] 3 4 5 6 7 8 9 
boot_device: eth flasheth ethonce flash [cfg] cfgonce 
boot_key: [any] del
boot_proto: [bootp] dhcp
booter: [regular] backup
cpu_mode: [powersave] regular
cpufreq_index: 0x00000370
silent_boot: [off] on
uart_speed: off 1200 2400 4800 9600 19200 38400 57600 [115200]

### DHCP SERVER LOGS

 ~/tftp % sudo ./loader.sh
dnsmasq: started, version 2.86 DNS disabled
dnsmasq: compile time options: IPv6 GNU-getopt DBus no-UBus i18n IDN2 DHCP DHCPv6 no-Lua TFTP conntrack ipset auth cryptohash DNSSEC loop-detect inotify dumpfile
dnsmasq-dhcp: DHCP, IP range 192.168.1.100 -- 192.168.1.120, lease time 1h

dnsmasq-dhcp: BOOTP(enp2s0) 192.168.1.101 18:fd:74:xx:xx:xx

alfa · December 24, 2022, 8:53am

Thanks

They didn't changed I will try resetting

echo "flasheth">/sys/firmware/mikrotik/soft_config/boot_device
ash: write error: Not supported

-rwxrwxrwx    1 root     root        4.0K Dec 15 11:09 /sys/firmware/mikrotik/soft_config/boot_device

echo "y">/sys/firmware/mikrotik/soft_config/commit
-ash: can't create /sys/firmware/mikrotik/soft_config/commit: Permission denied

johnth · December 24, 2022, 8:58am

Okay. I did not remember when soft_config & 4k sectors on mt7621 went read only / writable, sorry. (It should work on snapshot, not sure about 22.03)
Process here: https://help.mikrotik.com/docs/display/UM/hEX#heading-Resetbutton

750gr3 Reset button
The RouterBOOT reset button has the following functions. Press the button and apply the power, then:

Release the button when a green LED starts flashing, to reset RouterOS configuration to defaults.

Release the button when the LED turns solid green to clear all configuration and bridge all interfaces.

Release the button after LED is no longer lit (~20 seconds) to cause a device to look for Netinstall servers (required for reinstalling RouterOS over the network).

We want the first (or if that does not fix it—second) option. Supply power, then hold reset until LED does what we want, then release.

alfa · December 24, 2022, 11:22am

This solved my problem.
Thank you so much

system · January 3, 2023, 11:22am

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