serial: T8375: add CLI option to explicitly set kernel console

Previously, VyOS hardcoded the kernel boot log console to either ttyS0 or
tty0, with no post-install CLI method to change it (manual GRUB edits
were required).

This commit adds a new CLI node:
  system console device <name> kernel

When set, the selected serial console is used as the kernel boot console.
When removed, the kernel boot console falls back to tty0.

50 files changed, 138 insertions, 0 deletions

diff --git a/smoketest/configs/assert/basic-api-service b/smoketest/configs/assert/basic-api-service
index ca10cf4e9..06ac37eb6 100644
--- a/smoketest/configs/assert/basic-api-service
+++ b/smoketest/configs/assert/basic-api-service
@@ -20,6 +20,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'vyos'
 set system login user vyos authentication encrypted-password '$6$2Ta6TWHd/U$NmrX0x9kexCimeOcYK1MfhMpITF9ELxHcaBU/znBq.X2ukQOj61fVI2UYP/xBzP4QtiTcdkgs7WOQMHWsRymO/'
diff --git a/smoketest/configs/assert/basic-haproxy b/smoketest/configs/assert/basic-haproxy
index 7755fc4ea..b7a11ff74 100644
--- a/smoketest/configs/assert/basic-haproxy
+++ b/smoketest/configs/assert/basic-haproxy
@@ -35,6 +35,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'vyos'
 set system login user vyos authentication encrypted-password '$6$O5gJRlDYQpj$MtrCV9lxMnZPMbcxlU7.FI793MImNHznxGoMFgm3Q6QP3vfKJyOSRCt3Ka/GzFQyW1yZS4NS616NLHaIPPFHc0'
diff --git a/smoketest/configs/assert/basic-ipv6 b/smoketest/configs/assert/basic-ipv6
index 232a42a07..7bb4a8040 100644
--- a/smoketest/configs/assert/basic-ipv6
+++ b/smoketest/configs/assert/basic-ipv6
@@ -39,4 +39,5 @@ set system login user vyos authentication plaintext-password ''
 set system name-server '2001:db8::1'
 set system name-server '2001:db8::2'
 set system syslog local facility all level 'debug'
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
diff --git a/smoketest/configs/assert/basic-syslog b/smoketest/configs/assert/basic-syslog
index a8acc18e9..04c1b0568 100644
--- a/smoketest/configs/assert/basic-syslog
+++ b/smoketest/configs/assert/basic-syslog
@@ -4,6 +4,7 @@ set interfaces ethernet eth1 address '172.16.33.154/24'
 set interfaces ethernet eth1 duplex 'auto'
 set interfaces ethernet eth1 speed 'auto'
 set interfaces ethernet eth1 vrf 'red'
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system domain-name 'vyos-ci-test.net'
 set system host-name 'vyos'
diff --git a/smoketest/configs/assert/basic-system-ip-protocol b/smoketest/configs/assert/basic-system-ip-protocol
index 870ffa8f5..9d781bb16 100644
--- a/smoketest/configs/assert/basic-system-ip-protocol
+++ b/smoketest/configs/assert/basic-system-ip-protocol
@@ -1,3 +1,5 @@
+set system console device ttyS0 kernel
+set system console device ttyS0 speed '115200'
 set system ip protocol any route-map 'stub'
 set system ip protocol babel route-map 'stub'
 set system ip protocol bgp route-map 'stub'
diff --git a/smoketest/configs/assert/basic-vyos b/smoketest/configs/assert/basic-vyos
index 0f2cc730d..b6286c460 100644
--- a/smoketest/configs/assert/basic-vyos
+++ b/smoketest/configs/assert/basic-vyos
@@ -102,6 +102,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'vyos'
 set system login user vyos authentication encrypted-password '$6$O5gJRlDYQpj$MtrCV9lxMnZPMbcxlU7.FI793MImNHznxGoMFgm3Q6QP3vfKJyOSRCt3Ka/GzFQyW1yZS4NS616NLHaIPPFHc0'
diff --git a/smoketest/configs/assert/basic-vyos-no-ntp b/smoketest/configs/assert/basic-vyos-no-ntp
index f00dea5d4..036f0e638 100644
--- a/smoketest/configs/assert/basic-vyos-no-ntp
+++ b/smoketest/configs/assert/basic-vyos-no-ntp
@@ -42,6 +42,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system domain-name 'vyos.ci.net'
 set system host-name 'no-ntp'
diff --git a/smoketest/configs/assert/bgp-azure-ipsec-gateway b/smoketest/configs/assert/bgp-azure-ipsec-gateway
index 823a2c36a..b854adcb3 100644
--- a/smoketest/configs/assert/bgp-azure-ipsec-gateway
+++ b/smoketest/configs/assert/bgp-azure-ipsec-gateway
@@ -109,6 +109,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system domain-name 'vyos.net'
 set system flow-accounting netflow interface 'eth1'
diff --git a/smoketest/configs/assert/bgp-bfd-communities b/smoketest/configs/assert/bgp-bfd-communities
index 06e412c55..2935b4bc1 100644
--- a/smoketest/configs/assert/bgp-bfd-communities
+++ b/smoketest/configs/assert/bgp-bfd-communities
@@ -192,6 +192,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'vyos'
 set system login user vyos authentication encrypted-password '$6$2Ta6TWHd/U$NmrX0x9kexCimeOcYK1MfhMpITF9ELxHcaBU/znBq.X2ukQOj61fVI2UYP/xBzP4QtiTcdkgs7WOQMHWsRymO/'
diff --git a/smoketest/configs/assert/bgp-big-as-cloud b/smoketest/configs/assert/bgp-big-as-cloud
index 072f5258a..f8e671804 100644
--- a/smoketest/configs/assert/bgp-big-as-cloud
+++ b/smoketest/configs/assert/bgp-big-as-cloud
@@ -829,6 +829,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system flow-accounting netflow interface 'eth0.4088'
 set system flow-accounting netflow interface 'eth0.4089'
diff --git a/smoketest/configs/assert/bgp-dmvpn-hub b/smoketest/configs/assert/bgp-dmvpn-hub
index f9ceba11c..396bcbb1b 100644
--- a/smoketest/configs/assert/bgp-dmvpn-hub
+++ b/smoketest/configs/assert/bgp-dmvpn-hub
@@ -43,6 +43,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'cpe-4'
 set system login user vyos authentication encrypted-password '$6$r/Yw/07NXNY$/ZB.Rjf9jxEV.BYoDyLdH.kH14rU52pOBtrX.4S34qlPt77chflCHvpTCq9a6huLzwaMR50rEICzA5GoIRZlM0'
diff --git a/smoketest/configs/assert/bgp-dmvpn-spoke b/smoketest/configs/assert/bgp-dmvpn-spoke
index a98275ba4..949432849 100644
--- a/smoketest/configs/assert/bgp-dmvpn-spoke
+++ b/smoketest/configs/assert/bgp-dmvpn-spoke
@@ -49,6 +49,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'cpe-1'
 set system login user vyos authentication encrypted-password '$6$r/Yw/07NXNY$/ZB.Rjf9jxEV.BYoDyLdH.kH14rU52pOBtrX.4S34qlPt77chflCHvpTCq9a6huLzwaMR50rEICzA5GoIRZlM0'
diff --git a/smoketest/configs/assert/bgp-evpn-l2vpn-leaf b/smoketest/configs/assert/bgp-evpn-l2vpn-leaf
index 84cf0805e..f8be362c1 100644
--- a/smoketest/configs/assert/bgp-evpn-l2vpn-leaf
+++ b/smoketest/configs/assert/bgp-evpn-l2vpn-leaf
@@ -41,6 +41,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'vyos'
 set system login user vyos authentication encrypted-password '$6$O5gJRlDYQpj$MtrCV9lxMnZPMbcxlU7.FI793MImNHznxGoMFgm3Q6QP3vfKJyOSRCt3Ka/GzFQyW1yZS4NS616NLHaIPPFHc0'
diff --git a/smoketest/configs/assert/bgp-evpn-l2vpn-spine b/smoketest/configs/assert/bgp-evpn-l2vpn-spine
index 5d0a70398..1961491f5 100644
--- a/smoketest/configs/assert/bgp-evpn-l2vpn-spine
+++ b/smoketest/configs/assert/bgp-evpn-l2vpn-spine
@@ -34,6 +34,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'vyos'
 set system login user vyos authentication encrypted-password '$6$O5gJRlDYQpj$MtrCV9lxMnZPMbcxlU7.FI793MImNHznxGoMFgm3Q6QP3vfKJyOSRCt3Ka/GzFQyW1yZS4NS616NLHaIPPFHc0'
diff --git a/smoketest/configs/assert/bgp-evpn-l3vpn-pe-router b/smoketest/configs/assert/bgp-evpn-l3vpn-pe-router
index 88309e424..3193887fe 100644
--- a/smoketest/configs/assert/bgp-evpn-l3vpn-pe-router
+++ b/smoketest/configs/assert/bgp-evpn-l3vpn-pe-router
@@ -88,6 +88,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system domain-name 'vyos.net'
 set system host-name 'vyos'
diff --git a/smoketest/configs/assert/bgp-medium-confederation b/smoketest/configs/assert/bgp-medium-confederation
index 71797fe93..c8abe5a32 100644
--- a/smoketest/configs/assert/bgp-medium-confederation
+++ b/smoketest/configs/assert/bgp-medium-confederation
@@ -63,6 +63,7 @@ set protocols bgp peer-group WDC07v6 remote-as '670'
 set protocols bgp peer-group WDC07v6 update-source 'dum0'
 set protocols bgp system-as '670'
 set system config-management commit-revisions '200'
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system domain-name 'vyos.net'
 set system host-name 'vyos'
diff --git a/smoketest/configs/assert/bgp-rpki b/smoketest/configs/assert/bgp-rpki
index 657d4abcc..93b48cc97 100644
--- a/smoketest/configs/assert/bgp-rpki
+++ b/smoketest/configs/assert/bgp-rpki
@@ -36,6 +36,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'vyos'
 set system login user vyos authentication encrypted-password '$6$2Ta6TWHd/U$NmrX0x9kexCimeOcYK1MfhMpITF9ELxHcaBU/znBq.X2ukQOj61fVI2UYP/xBzP4QtiTcdkgs7WOQMHWsRymO/'
diff --git a/smoketest/configs/assert/bgp-small-internet-exchange b/smoketest/configs/assert/bgp-small-internet-exchange
index 2adb3fbb5..61ee9755b 100644
--- a/smoketest/configs/assert/bgp-small-internet-exchange
+++ b/smoketest/configs/assert/bgp-small-internet-exchange
@@ -201,6 +201,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'vyos'
 set system login user vyos authentication encrypted-password '$6$2Ta6TWHd/U$NmrX0x9kexCimeOcYK1MfhMpITF9ELxHcaBU/znBq.X2ukQOj61fVI2UYP/xBzP4QtiTcdkgs7WOQMHWsRymO/'
diff --git a/smoketest/configs/assert/bgp-small-ipv4-unicast b/smoketest/configs/assert/bgp-small-ipv4-unicast
index f8820cb3c..a50a81732 100644
--- a/smoketest/configs/assert/bgp-small-ipv4-unicast
+++ b/smoketest/configs/assert/bgp-small-ipv4-unicast
@@ -23,6 +23,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system domain-name 'vyos.net'
 set system host-name 'vyos'
diff --git a/smoketest/configs/assert/cluster-basic b/smoketest/configs/assert/cluster-basic
index 871b40bbb..039470177 100644
--- a/smoketest/configs/assert/cluster-basic
+++ b/smoketest/configs/assert/cluster-basic
@@ -12,6 +12,7 @@ set interfaces ethernet eth1 duplex 'auto'
 set interfaces ethernet eth1 speed 'auto'
 set interfaces loopback lo
 set system config-management commit-revisions '100'
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'vyos'
 set system login user vyos authentication encrypted-password '$6$O5gJRlDYQpj$MtrCV9lxMnZPMbcxlU7.FI793MImNHznxGoMFgm3Q6QP3vfKJyOSRCt3Ka/GzFQyW1yZS4NS616NLHaIPPFHc0'
diff --git a/smoketest/configs/assert/conntrack-basic b/smoketest/configs/assert/conntrack-basic
index 8c375d244..424cefb4e 100644
--- a/smoketest/configs/assert/conntrack-basic
+++ b/smoketest/configs/assert/conntrack-basic
@@ -24,6 +24,7 @@ set system conntrack modules sqlnet
 set system conntrack modules tftp
 set system conntrack table-size '262144'
 set system conntrack timeout
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system domain-name 'vyos.net'
 set system host-name 'vyos'
diff --git a/smoketest/configs/assert/container-simple b/smoketest/configs/assert/container-simple
index fcc665100..b9a720393 100644
--- a/smoketest/configs/assert/container-simple
+++ b/smoketest/configs/assert/container-simple
@@ -12,6 +12,7 @@ set interfaces ethernet eth0 speed 'auto'
 set interfaces ethernet eth1 duplex 'auto'
 set interfaces ethernet eth1 speed 'auto'
 set system config-management commit-revisions '50'
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'vyos'
 set system login user vyos authentication encrypted-password '$6$r/Yw/07NXNY$/ZB.Rjf9jxEV.BYoDyLdH.kH14rU52pOBtrX.4S34qlPt77chflCHvpTCq9a6huLzwaMR50rEICzA5GoIRZlM0'
diff --git a/smoketest/configs/assert/dialup-router-complex b/smoketest/configs/assert/dialup-router-complex
index 12edcfef2..b244dc866 100644
--- a/smoketest/configs/assert/dialup-router-complex
+++ b/smoketest/configs/assert/dialup-router-complex
@@ -726,6 +726,7 @@ set system conntrack modules sqlnet
 set system conntrack modules tftp
 set system conntrack table-size '262144'
 set system conntrack timeout
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system domain-name 'vyos.net'
 set system host-name 'vyos'
diff --git a/smoketest/configs/assert/dialup-router-medium-vpn b/smoketest/configs/assert/dialup-router-medium-vpn
index 87b35b18c..226aa64be 100644
--- a/smoketest/configs/assert/dialup-router-medium-vpn
+++ b/smoketest/configs/assert/dialup-router-medium-vpn
@@ -296,6 +296,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'vyos'
 set system ip arp table-size '1024'
diff --git a/smoketest/configs/assert/dialup-router-wireguard-ipv6 b/smoketest/configs/assert/dialup-router-wireguard-ipv6
index 269e9d722..761d65cda 100644
--- a/smoketest/configs/assert/dialup-router-wireguard-ipv6
+++ b/smoketest/configs/assert/dialup-router-wireguard-ipv6
@@ -681,6 +681,7 @@ set system conntrack modules sqlnet
 set system conntrack modules tftp
 set system conntrack table-size '262144'
 set system conntrack timeout
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system domain-name 'vyos.net'
 set system host-name 'r1'
diff --git a/smoketest/configs/assert/dns-dynamic b/smoketest/configs/assert/dns-dynamic
index f40563016..1448847ec 100644
--- a/smoketest/configs/assert/dns-dynamic
+++ b/smoketest/configs/assert/dns-dynamic
@@ -25,6 +25,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'vyos'
 set system login user vyos authentication encrypted-password '$6$YuG5oKoRYQnbnxk$P2eZNlIwXJP82JFyFrF2g4ZoOZr6zgLHK.SDJVoqWDGefKkRrJijUZODAVMLeWU.9EGM48YtG9MwfuewWoOGE.'
diff --git a/smoketest/configs/assert/egp-igp-route-maps b/smoketest/configs/assert/egp-igp-route-maps
index 222325cd7..0d12c1fb6 100644
--- a/smoketest/configs/assert/egp-igp-route-maps
+++ b/smoketest/configs/assert/egp-igp-route-maps
@@ -29,6 +29,7 @@ set protocols ospfv3 parameters router-id '1.1.1.1'
 set protocols ripng interface eth1
 set protocols static
 set system config-management commit-revisions '100'
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'vyos'
 set system ip protocol bgp route-map 'zebra-bgp'
diff --git a/smoketest/configs/assert/firewall-bridged-global-options b/smoketest/configs/assert/firewall-bridged-global-options
index 1d960d6c1..59b9b4397 100644
--- a/smoketest/configs/assert/firewall-bridged-global-options
+++ b/smoketest/configs/assert/firewall-bridged-global-options
@@ -14,6 +14,7 @@ set interfaces ethernet eth0 duplex 'auto'
 set interfaces ethernet eth0 speed 'auto'
 set interfaces ethernet eth1 duplex 'auto'
 set interfaces ethernet eth1 speed 'auto'
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system domain-name 'vyos-ci-test.net'
 set system host-name 'vyos'
diff --git a/smoketest/configs/assert/firewall-empty-nodes b/smoketest/configs/assert/firewall-empty-nodes
index c0fcd93be..91aeb273a 100644
--- a/smoketest/configs/assert/firewall-empty-nodes
+++ b/smoketest/configs/assert/firewall-empty-nodes
@@ -25,6 +25,7 @@ set interfaces ethernet eth0
 set interfaces ethernet eth1
 set interfaces ethernet eth2
 set interfaces loopback lo
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'vyos'
 set system login user vyos authentication encrypted-password '$6$O5gJRlDYQpj$MtrCV9lxMnZPMbcxlU7.FI793MImNHznxGoMFgm3Q6QP3vfKJyOSRCt3Ka/GzFQyW1yZS4NS616NLHaIPPFHc0'
diff --git a/smoketest/configs/assert/igmp-pim-small b/smoketest/configs/assert/igmp-pim-small
index 06051af41..561cf4c16 100644
--- a/smoketest/configs/assert/igmp-pim-small
+++ b/smoketest/configs/assert/igmp-pim-small
@@ -27,6 +27,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system domain-name 'vyos.io'
 set system host-name 'vyos'
diff --git a/smoketest/configs/assert/ipoe-server b/smoketest/configs/assert/ipoe-server
index c21495ab2..5c3863485 100644
--- a/smoketest/configs/assert/ipoe-server
+++ b/smoketest/configs/assert/ipoe-server
@@ -40,6 +40,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'vyos'
 set system login user vyos authentication encrypted-password '$6$O5gJRlDYQpj$MtrCV9lxMnZPMbcxlU7.FI793MImNHznxGoMFgm3Q6QP3vfKJyOSRCt3Ka/GzFQyW1yZS4NS616NLHaIPPFHc0'
diff --git a/smoketest/configs/assert/ipv6-disable b/smoketest/configs/assert/ipv6-disable
index 5f906b5f7..77d585f2d 100644
--- a/smoketest/configs/assert/ipv6-disable
+++ b/smoketest/configs/assert/ipv6-disable
@@ -20,6 +20,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system domain-name 'vyos.net'
 set system host-name 'vyos'
diff --git a/smoketest/configs/assert/isis-small b/smoketest/configs/assert/isis-small
index e61d0362e..cefc0ad51 100644
--- a/smoketest/configs/assert/isis-small
+++ b/smoketest/configs/assert/isis-small
@@ -31,6 +31,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system domain-name 'vyos.io'
 set system host-name 'vyos'
diff --git a/smoketest/configs/assert/nat-basic b/smoketest/configs/assert/nat-basic
index f1cc0121d..e7e6916b0 100644
--- a/smoketest/configs/assert/nat-basic
+++ b/smoketest/configs/assert/nat-basic
@@ -77,6 +77,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system domain-name 'vyos.net'
 set system host-name 'R1'
diff --git a/smoketest/configs/assert/ospf-simple b/smoketest/configs/assert/ospf-simple
index 4273e4b8f..02410a3f7 100644
--- a/smoketest/configs/assert/ospf-simple
+++ b/smoketest/configs/assert/ospf-simple
@@ -16,6 +16,7 @@ set protocols ospf interface eth0.666 passive
 set protocols ospf log-adjacency-changes detail
 set protocols static route 0.0.0.0/0 next-hop 193.201.42.170 distance '130'
 set system config-management commit-revisions '100'
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'lab-vyos-r1'
 set system login user vyos authentication encrypted-password '$6$R.OnGzfXSfl6J$Iba/hl9bmjBs0VPtZ2zdW.Snh/nHuvxUwi0R6ruypgW63iKEbicJH.uUst8xZCyByURblxRtjAC1lAnYfIt.b0'
diff --git a/smoketest/configs/assert/ospf-small b/smoketest/configs/assert/ospf-small
index af69e5702..811e4af3c 100644
--- a/smoketest/configs/assert/ospf-small
+++ b/smoketest/configs/assert/ospf-small
@@ -65,6 +65,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system domain-name 'vyos.net'
 set system host-name 'vyos'
diff --git a/smoketest/configs/assert/pppoe-server b/smoketest/configs/assert/pppoe-server
index e488fc746..dd9429fc3 100644
--- a/smoketest/configs/assert/pppoe-server
+++ b/smoketest/configs/assert/pppoe-server
@@ -39,6 +39,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'vyos'
 set system login user vyos authentication encrypted-password '$6$O5gJRlDYQpj$MtrCV9lxMnZPMbcxlU7.FI793MImNHznxGoMFgm3Q6QP3vfKJyOSRCt3Ka/GzFQyW1yZS4NS616NLHaIPPFHc0'
diff --git a/smoketest/configs/assert/qos-basic b/smoketest/configs/assert/qos-basic
index 655a5794e..a9d044c0e 100644
--- a/smoketest/configs/assert/qos-basic
+++ b/smoketest/configs/assert/qos-basic
@@ -67,6 +67,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'vyos'
 set system login user vyos authentication encrypted-password '$6$r/Yw/07NXNY$/ZB.Rjf9jxEV.BYoDyLdH.kH14rU52pOBtrX.4S34qlPt77chflCHvpTCq9a6huLzwaMR50rEICzA5GoIRZlM0'
diff --git a/smoketest/configs/assert/rip-router b/smoketest/configs/assert/rip-router
index d22f424a5..5d868dcba 100644
--- a/smoketest/configs/assert/rip-router
+++ b/smoketest/configs/assert/rip-router
@@ -75,6 +75,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'vyos'
 set system login user vyos authentication encrypted-password '$6$O5gJRlDYQpj$MtrCV9lxMnZPMbcxlU7.FI793MImNHznxGoMFgm3Q6QP3vfKJyOSRCt3Ka/GzFQyW1yZS4NS616NLHaIPPFHc0'
diff --git a/smoketest/configs/assert/rpki-only b/smoketest/configs/assert/rpki-only
index f3e2a74b9..8c49e6c01 100644
--- a/smoketest/configs/assert/rpki-only
+++ b/smoketest/configs/assert/rpki-only
@@ -34,6 +34,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'vyos'
 set system login user vyos authentication encrypted-password '$6$r/Yw/07NXNY$/ZB.Rjf9jxEV.BYoDyLdH.kH14rU52pOBtrX.4S34qlPt77chflCHvpTCq9a6huLzwaMR50rEICzA5GoIRZlM0'
diff --git a/smoketest/configs/assert/static-route-basic b/smoketest/configs/assert/static-route-basic
index a6135d2c4..06567531d 100644
--- a/smoketest/configs/assert/static-route-basic
+++ b/smoketest/configs/assert/static-route-basic
@@ -28,6 +28,7 @@ set service ntp server 172.16.100.10
 set service ntp server 172.16.100.20
 set service ntp server 172.16.110.30
 set system config-management commit-revisions '100'
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'vyos'
 set system login user vyos authentication encrypted-password '$6$O5gJRlDYQpj$MtrCV9lxMnZPMbcxlU7.FI793MImNHznxGoMFgm3Q6QP3vfKJyOSRCt3Ka/GzFQyW1yZS4NS616NLHaIPPFHc0'
diff --git a/smoketest/configs/assert/tunnel-broker b/smoketest/configs/assert/tunnel-broker
index 5518c303b..209160326 100644
--- a/smoketest/configs/assert/tunnel-broker
+++ b/smoketest/configs/assert/tunnel-broker
@@ -67,6 +67,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'vyos'
 set system login user vyos authentication encrypted-password '$6$O5gJRlDYQpj$MtrCV9lxMnZPMbcxlU7.FI793MImNHznxGoMFgm3Q6QP3vfKJyOSRCt3Ka/GzFQyW1yZS4NS616NLHaIPPFHc0'
diff --git a/smoketest/configs/assert/vpn-openconnect-sstp b/smoketest/configs/assert/vpn-openconnect-sstp
index e7969f633..a897a696b 100644
--- a/smoketest/configs/assert/vpn-openconnect-sstp
+++ b/smoketest/configs/assert/vpn-openconnect-sstp
@@ -12,6 +12,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'vyos'
 set system login user vyos authentication encrypted-password '$6$2Ta6TWHd/U$NmrX0x9kexCimeOcYK1MfhMpITF9ELxHcaBU/znBq.X2ukQOj61fVI2UYP/xBzP4QtiTcdkgs7WOQMHWsRymO/'
diff --git a/smoketest/configs/assert/vpn-openvpn b/smoketest/configs/assert/vpn-openvpn
index f7b9857de..e8da06fd0 100644
--- a/smoketest/configs/assert/vpn-openvpn
+++ b/smoketest/configs/assert/vpn-openvpn
@@ -145,6 +145,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system domain-name 'vyos.io'
 set system host-name 'vyos'
diff --git a/smoketest/configs/assert/vpp b/smoketest/configs/assert/vpp
index 7d8fcb7a7..32671696e 100644
--- a/smoketest/configs/assert/vpp
+++ b/smoketest/configs/assert/vpp
@@ -11,6 +11,7 @@ set interfaces ethernet eth3
 set interfaces ethernet eth4 description 'Bonding'
 set interfaces loopback lo
 set system config-management commit-revisions '100'
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'r16'
 set system login user vyos authentication encrypted-password '$6$rounds=656000$FZBlGpWsmSrV2Rvq$YPNAPtk4k6u99FAMxR6cw4DUPCgOomwCgRZRSO5rAoJK8RlMSCkVAFVF3ozL/3mZMfxcuCnwvd5HX6f9V5KzO.'
diff --git a/smoketest/configs/assert/vrf-basic b/smoketest/configs/assert/vrf-basic
index 0c4e49c52..775f84e8f 100644
--- a/smoketest/configs/assert/vrf-basic
+++ b/smoketest/configs/assert/vrf-basic
@@ -31,6 +31,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'vyos'
 set system login user vyos authentication encrypted-password '$6$O5gJRlDYQpj$MtrCV9lxMnZPMbcxlU7.FI793MImNHznxGoMFgm3Q6QP3vfKJyOSRCt3Ka/GzFQyW1yZS4NS616NLHaIPPFHc0'
diff --git a/smoketest/configs/assert/vrf-bgp-pppoe-underlay b/smoketest/configs/assert/vrf-bgp-pppoe-underlay
index e3c765a9a..f15e7c109 100644
--- a/smoketest/configs/assert/vrf-bgp-pppoe-underlay
+++ b/smoketest/configs/assert/vrf-bgp-pppoe-underlay
@@ -137,6 +137,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system domain-name 'vyos.net'
 set system host-name 'vyos'
diff --git a/smoketest/configs/assert/vrf-ospf b/smoketest/configs/assert/vrf-ospf
index 53207d565..c57e7cd2e 100644
--- a/smoketest/configs/assert/vrf-ospf
+++ b/smoketest/configs/assert/vrf-ospf
@@ -24,6 +24,7 @@ set system conntrack modules pptp
 set system conntrack modules sip
 set system conntrack modules sqlnet
 set system conntrack modules tftp
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system host-name 'vyos'
 set system login user vyos authentication encrypted-password '$6$O5gJRlDYQpj$MtrCV9lxMnZPMbcxlU7.FI793MImNHznxGoMFgm3Q6QP3vfKJyOSRCt3Ka/GzFQyW1yZS4NS616NLHaIPPFHc0'
diff --git a/smoketest/configs/assert/wireless-basic b/smoketest/configs/assert/wireless-basic
index e424b2b0f..03ad767cb 100644
--- a/smoketest/configs/assert/wireless-basic
+++ b/smoketest/configs/assert/wireless-basic
@@ -16,6 +16,7 @@ set interfaces wireless wlan1 mode 'n'
 set interfaces wireless wlan1 ssid 'VyOS-PUBLIC'
 set interfaces wireless wlan1 type 'access-point'
 set system config-management commit-revisions '200'
+set system console device ttyS0 kernel
 set system console device ttyS0 speed '115200'
 set system domain-name 'dev.vyos.net'
 set system host-name 'WR1'
diff --git a/smoketest/scripts/cli/test_system_console.py b/smoketest/scripts/cli/test_system_console.py
new file mode 100755
index 000000000..388e9236f
--- /dev/null
+++ b/smoketest/scripts/cli/test_system_console.py
@@ -0,0 +1,88 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) VyOS Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 or later as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import os
+import unittest
+
+from base_vyostest_shim import VyOSUnitTestSHIM
+
+from vyos.configsession import ConfigSessionError
+from vyos.system import disk
+from vyos.system.grub import CFG_VYOS_VARS
+from vyos.system.grub import vars_read
+from vyos.xml_ref import default_value
+
+base_path = ['system', 'console']
+serial_console = 'ttyS0'
+default_speed = default_value(base_path + ['device', serial_console, 'speed'])
+
+def get_grub_vars() -> dict:
+    root_dir = disk.find_persistence()
+    vars_file: str = f'{root_dir}/{CFG_VYOS_VARS}'
+    vars_current: dict[str, str] = vars_read(vars_file)
+    return vars_current
+
+class TestSystemConsole(VyOSUnitTestSHIM.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        super(TestSystemConsole, cls).setUpClass()
+
+        # ensure we can also run this test on a live system - so lets clean
+        # out the current configuration :)
+        cls.cli_delete(cls, base_path)
+        cls.cli_commit(cls)
+
+    def tearDown(self):
+        self.cli_delete(base_path)
+        self.cli_commit()
+        # always forward to base class
+        super().tearDown()
+
+    def test_multiple_kernel_consoles(self):
+        self.cli_set(base_path + ['device', 'ttyS1', 'kernel'])
+        self.cli_set(base_path + ['device', 'ttyS2', 'kernel'])
+
+        # Only one console can have 'kernel'
+        with self.assertRaises(ConfigSessionError):
+            self.cli_commit()
+
+    def test_fbcon_and_serial_con_switch(self):
+        if not os.path.exists('/tmp/vyos.smoketests.hint'):
+            self.skipTest('Not running under VyOS CI/CD QEMU environment!')
+
+        grub_vars = get_grub_vars()
+        # we have deleted the CLI config in tearDown() so the default is now
+        # the framebuffer console at tty0
+        self.assertEqual(grub_vars['console_type'], 'tty')
+
+        self.cli_set(base_path + ['device', serial_console, 'kernel'])
+        self.cli_commit()
+
+        grub_vars = get_grub_vars()
+        # We moved the Kernel boot console to ttyS0
+        self.assertEqual(grub_vars['console_type'], serial_console[:-1])
+        self.assertEqual(grub_vars['console_num'], serial_console[-1])
+        self.assertEqual(grub_vars['console_speed'], default_speed)
+
+        self.cli_delete(base_path)
+        self.cli_commit()
+
+        # We moved back to tty as Kernel boot console
+        grub_vars = get_grub_vars()
+        self.assertEqual(grub_vars['console_type'], 'tty')
+
+if __name__ == '__main__':
+    unittest.main(verbosity=2, failfast=VyOSUnitTestSHIM.TestCase.debug_on())