Cannot boot with initial initramfs on MikroTik RB5009UG+S+IN

lweller · March 26, 2026, 2:59pm

Hi Floks

Ich try to setup my new MikroTik RB5009UG+S+IN with OpenWRT. But I’m already stuck with the first step accorsind to this Topic: OpenWrt Installation fails on MikroTik RB5009UG+S+IN

I managed to setup a dhcp/tftp server with dnsmasq and it seams to get honored when I reboot my MikroTik:

[lucien@wks-weller02]~/mikrotik>sudo firewall-cmd --add-service=dhcp
success
[lucien@wks-weller02]~/mikrotik>sudo firewall-cmd --add-service=tftp
success
[lucien@wks-weller02]~/mikrotik>ls
openwrt-mvebu-cortexa72-mikrotik_rb5009-initramfs-uImage.itb u-boot.elf
[lucien@wks-weller02]~/mikrotik>sudo dnsmasq --user=lucien --no-daemon --listen-address 192.168.1.10 --bind-interfaces -p0 --dhcp-authoritative --dhcp-range=192.168.1.100,192.168.1.200 --bootp-dynamic --dhcp-boot=u-boot.elf --log-dhcp --enable-tftp --tftp-root=$(pwd)
dnsmasq: started, version 2.92 DNS disabled
dnsmasq: compile time options: IPv6 GNU-getopt DBus no-UBus i18n IDN2 DHCP DHCPv6 no-Lua TFTP conntrack ipset nftset auth DNSSEC loop-detect inotify dumpfile
dnsmasq-dhcp: DHCP, IP range 192.168.1.100 -- 192.168.1.200, lease time 1h
dnsmasq-tftp: TFTP root is /home/lucien/mikrotik
dnsmasq-dhcp: 807558742 available DHCP range: 192.168.1.100 -- 192.168.1.200
dnsmasq-dhcp: 807558742 vendor class: Flashboot
dnsmasq-dhcp: 807558742 tags: bootp, enp0s31f6
dnsmasq-dhcp: 807558742 BOOTP(enp0s31f6) 192.168.1.122 f4:1e:57:eb:02:77
dnsmasq-dhcp: 807558742 bootfile name: u-boot.elf
dnsmasq-dhcp: 807558742 next server: 192.168.1.10
dnsmasq-dhcp: 807558742 sent size: 4 option: 1 netmask 255.255.255.0
dnsmasq-dhcp: 807558742 sent size: 4 option: 28 broadcast 192.168.1.255
dnsmasq-dhcp: 807558742 sent size: 4 option: 3 router 192.168.1.10
dnsmasq-tftp: sent /home/lucien/mikrotik/u-boot.elf to 192.168.1.122

But when I after a while then unplug the cable from port 1 (2.5G) ) and insert it into port 2 didnt get a running OpenWrt on 192.168.1.1 as expected, but access still RouterOS on 192.168.88.1.

Has anybody an advice what I’m doing wrong?

frollic · March 26, 2026, 3:10pm

u-boot.elf isn't an openwrt image.

lweller · March 26, 2026, 9:47pm

@frollic, you’re right, u-boot.elf ist just a boot load required for compatibility reasons with RB5009. The initramfs is loaded in a second step.

But I finally found the issue: I just not pressed the reset button long enough. I released it when LED started blinking. You havae to maintain it pressed until both u-boot.elf snd initdamfs have been fetched, so until you get this two lines in dnsmasq logs:

[lucien@wks-weller02]~/mikrotik>sudo dnsmasq --no-daemon --listen-address 192.168.1.10 --bind-interfaces -p0 --dhcp-authoritative --dhcp-range=192.168.1.100,192.168.1.200 --bootp-dynamic --dhcp-boot=u-boot.elf --log-dhcp --enable-tftp --tftp-root=$(pwd)
dnsmasq: started, version 2.92 DNS disabled
dnsmasq: compile time options: IPv6 GNU-getopt DBus no-UBus i18n IDN2 DHCP DHCPv6 no-Lua TFTP conntrack ipset nftset auth DNSSEC loop-detect inotify dumpfile
dnsmasq-dhcp: DHCP, IP range 192.168.1.100 -- 192.168.1.200, lease time 1h
dnsmasq-tftp: TFTP root is /home/lucien/mikrotik
dnsmasq-dhcp: 1991294218 available DHCP range: 192.168.1.100 -- 192.168.1.200
dnsmasq-dhcp: 1991294218 vendor class: ARM64__boot
dnsmasq-dhcp: 1991294218 tags: bootp, enp0s31f6
dnsmasq-dhcp: 1991294218 BOOTP(enp0s31f6) 192.168.1.122 f4:1e:57:eb:02:77
dnsmasq-dhcp: 1991294218 bootfile name: u-boot.elf
dnsmasq-dhcp: 1991294218 next server: 192.168.1.10
dnsmasq-dhcp: 1991294218 sent size: 4 option: 1 netmask 255.255.255.0
dnsmasq-dhcp: 1991294218 sent size: 4 option: 28 broadcast 192.168.1.255
dnsmasq-dhcp: 1991294218 sent size: 4 option: 3 router 192.168.1.10
dnsmasq-tftp: sent /home/lucien/mikrotik/u-boot.elf to 192.168.1.122
dnsmasq-dhcp: 561596123 available DHCP range: 192.168.1.100 -- 192.168.1.200
dnsmasq-dhcp: 561596123 vendor class: U-Boot.armv8
dnsmasq-dhcp: 561596123 DHCPDISCOVER(enp0s31f6) 76:6f:21:78:dd:7f
dnsmasq-dhcp: 561596123 tags: enp0s31f6
dnsmasq-dhcp: 561596123 DHCPOFFER(enp0s31f6) 192.168.1.103 76:6f:21:78:dd:7f
dnsmasq-dhcp: 561596123 requested options: 1:netmask, 3:router, 6:dns-server, 12:hostname,
dnsmasq-dhcp: 561596123 requested options: 17:root-path, 209
dnsmasq-dhcp: 561596123 bootfile name: u-boot.elf
dnsmasq-dhcp: 561596123 next server: 192.168.1.10
dnsmasq-dhcp: 561596123 sent size: 1 option: 53 message-type 2
dnsmasq-dhcp: 561596123 sent size: 4 option: 54 server-identifier 192.168.1.10
dnsmasq-dhcp: 561596123 sent size: 4 option: 51 lease-time 1h
dnsmasq-dhcp: 561596123 sent size: 4 option: 58 T1 30m
dnsmasq-dhcp: 561596123 sent size: 4 option: 59 T2 52m30s
dnsmasq-dhcp: 561596123 sent size: 4 option: 1 netmask 255.255.255.0
dnsmasq-dhcp: 561596123 sent size: 4 option: 28 broadcast 192.168.1.255
dnsmasq-dhcp: 561596123 sent size: 4 option: 3 router 192.168.1.10
dnsmasq-dhcp: 561596123 available DHCP range: 192.168.1.100 -- 192.168.1.200
dnsmasq-dhcp: 561596123 vendor class: U-Boot.armv8
dnsmasq-dhcp: 561596123 DHCPDISCOVER(enp0s31f6) 76:6f:21:78:dd:7f
dnsmasq-dhcp: 561596123 tags: enp0s31f6
dnsmasq-dhcp: 561596123 DHCPOFFER(enp0s31f6) 192.168.1.103 76:6f:21:78:dd:7f
dnsmasq-dhcp: 561596123 requested options: 1:netmask, 3:router, 6:dns-server, 12:hostname,
dnsmasq-dhcp: 561596123 requested options: 17:root-path, 209
dnsmasq-dhcp: 561596123 bootfile name: u-boot.elf
dnsmasq-dhcp: 561596123 next server: 192.168.1.10
dnsmasq-dhcp: 561596123 sent size: 1 option: 53 message-type 2
dnsmasq-dhcp: 561596123 sent size: 4 option: 54 server-identifier 192.168.1.10
dnsmasq-dhcp: 561596123 sent size: 4 option: 51 lease-time 1h
dnsmasq-dhcp: 561596123 sent size: 4 option: 58 T1 30m
dnsmasq-dhcp: 561596123 sent size: 4 option: 59 T2 52m30s
dnsmasq-dhcp: 561596123 sent size: 4 option: 1 netmask 255.255.255.0
dnsmasq-dhcp: 561596123 sent size: 4 option: 28 broadcast 192.168.1.255
dnsmasq-dhcp: 561596123 sent size: 4 option: 3 router 192.168.1.10
dnsmasq-dhcp: 561596123 available DHCP range: 192.168.1.100 -- 192.168.1.200
dnsmasq-dhcp: 561596123 vendor class: U-Boot.armv8
dnsmasq-dhcp: 561596123 DHCPDISCOVER(enp0s31f6) 76:6f:21:78:dd:7f
dnsmasq-dhcp: 561596123 tags: enp0s31f6
dnsmasq-dhcp: 561596123 DHCPOFFER(enp0s31f6) 192.168.1.103 76:6f:21:78:dd:7f
dnsmasq-dhcp: 561596123 requested options: 1:netmask, 3:router, 6:dns-server, 12:hostname,
dnsmasq-dhcp: 561596123 requested options: 17:root-path, 209
dnsmasq-dhcp: 561596123 bootfile name: u-boot.elf
dnsmasq-dhcp: 561596123 next server: 192.168.1.10
dnsmasq-dhcp: 561596123 sent size: 1 option: 53 message-type 2
dnsmasq-dhcp: 561596123 sent size: 4 option: 54 server-identifier 192.168.1.10
dnsmasq-dhcp: 561596123 sent size: 4 option: 51 lease-time 1h
dnsmasq-dhcp: 561596123 sent size: 4 option: 58 T1 30m
dnsmasq-dhcp: 561596123 sent size: 4 option: 59 T2 52m30s
dnsmasq-dhcp: 561596123 sent size: 4 option: 1 netmask 255.255.255.0
dnsmasq-dhcp: 561596123 sent size: 4 option: 28 broadcast 192.168.1.255
dnsmasq-dhcp: 561596123 sent size: 4 option: 3 router 192.168.1.10
dnsmasq-dhcp: 561596123 available DHCP range: 192.168.1.100 -- 192.168.1.200
dnsmasq-dhcp: 561596123 vendor class: U-Boot.armv8
dnsmasq-dhcp: 561596123 DHCPDISCOVER(enp0s31f6) 76:6f:21:78:dd:7f
dnsmasq-dhcp: 561596123 tags: enp0s31f6
dnsmasq-dhcp: 561596123 DHCPOFFER(enp0s31f6) 192.168.1.103 76:6f:21:78:dd:7f
dnsmasq-dhcp: 561596123 requested options: 1:netmask, 3:router, 6:dns-server, 12:hostname,
dnsmasq-dhcp: 561596123 requested options: 17:root-path, 209
dnsmasq-dhcp: 561596123 bootfile name: u-boot.elf
dnsmasq-dhcp: 561596123 next server: 192.168.1.10
dnsmasq-dhcp: 561596123 sent size: 1 option: 53 message-type 2
dnsmasq-dhcp: 561596123 sent size: 4 option: 54 server-identifier 192.168.1.10
dnsmasq-dhcp: 561596123 sent size: 4 option: 51 lease-time 1h
dnsmasq-dhcp: 561596123 sent size: 4 option: 58 T1 30m
dnsmasq-dhcp: 561596123 sent size: 4 option: 59 T2 52m30s
dnsmasq-dhcp: 561596123 sent size: 4 option: 1 netmask 255.255.255.0
dnsmasq-dhcp: 561596123 sent size: 4 option: 28 broadcast 192.168.1.255
dnsmasq-dhcp: 561596123 sent size: 4 option: 3 router 192.168.1.10
dnsmasq-dhcp: 561596123 available DHCP range: 192.168.1.100 -- 192.168.1.200
dnsmasq-dhcp: 561596123 vendor class: U-Boot.armv8
dnsmasq-dhcp: 561596123 DHCPREQUEST(enp0s31f6) 192.168.1.103 76:6f:21:78:dd:7f
dnsmasq-dhcp: 561596123 tags: enp0s31f6
dnsmasq-dhcp: 561596123 DHCPACK(enp0s31f6) 192.168.1.103 76:6f:21:78:dd:7f
dnsmasq-dhcp: 561596123 requested options: 1:netmask, 3:router, 6:dns-server, 12:hostname,
dnsmasq-dhcp: 561596123 requested options: 17:root-path, 209
dnsmasq-dhcp: 561596123 bootfile name: u-boot.elf
dnsmasq-dhcp: 561596123 next server: 192.168.1.10
dnsmasq-dhcp: 561596123 sent size: 1 option: 53 message-type 5
dnsmasq-dhcp: 561596123 sent size: 4 option: 54 server-identifier 192.168.1.10
dnsmasq-dhcp: 561596123 sent size: 4 option: 51 lease-time 1h
dnsmasq-dhcp: 561596123 sent size: 4 option: 58 T1 30m
dnsmasq-dhcp: 561596123 sent size: 4 option: 59 T2 52m30s
dnsmasq-dhcp: 561596123 sent size: 4 option: 1 netmask 255.255.255.0
dnsmasq-dhcp: 561596123 sent size: 4 option: 28 broadcast 192.168.1.255
dnsmasq-dhcp: 561596123 sent size: 4 option: 3 router 192.168.1.10
dnsmasq-tftp: sent /home/lucien/mikrotik/u-boot.elf to 192.168.1.103
dnsmasq-tftp: sent /home/lucien/mikrotik/openwrt-mvebu-cortexa72-mikrotik_rb5009-initramfs-uImage.itb to 192.168.1.103

system · April 5, 2026, 9:48pm

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