Is there a way to see the kernel booting logs during the booting process?

[Slone123c]

When I tried booting from a vm, I can see the following:

iPXE 1.21.1+ (g22653) -- Open Source Network Boot Firmware -- https://ipxe.org
Features: DNS HTTP iSCSI TFTP VLAN SRP AoE EFI Menu

net0: 52:54:00:92:6c:08 using virtio-net on 0000:00:03.0 (Ethernet) [open]
  [Link:up, TX:0 TXE:1 RX:0 RXE:0]
  [TXE: 1 x "Network unreachable (https://ipxe.org/28086090)"]
Configuring (net0 52:54:00:92:6c:08)...... ok
net0: 10.1.1.157/255.255.255.0 gw 10.1.1.1
net0: fe80::5054:ff:fe92:6c08/64
Next server: 10.1.1.11
Filename: boot.ipxe
tftp://10.1.1.11/boot.ipxe... ok
boot.ipxe : 297 bytes [script]
"##########################ipxe script loaded!###########################"
http://10.1.1.11/vmlinuz_mega... ok
http://10.1.1.11/initramfs_std_mega.gz... ok 
vmlinuz_mega : 11671784 bytes [EFI] [SELECTED] "root=/dev/ram0 earlyprintk=serial,ttyS0,115200n8 console=ttyS0,115200n8 debug udev.event-timeout=5 loglevel=7"
initramfs_std_mega.gz : 223862353 bytes
EFI stub: Loaded initrd from LINUX_EFI_INITRD_MEDIA_GUID device path

[    0.000000] Linux version 5.15.0-104-generic (buildd@lcy02-amd64-019) (gcc (Ubuntu 11.4.0-1ubuntu1~22.04) 11.4.0, GNU ld (GNU Binutils for Ubuntu) 2.38) #114-Ubuntu SMP Thu Mar 28 15:39:51 UTC 2024 (Ubuntu 5.15.0-104.114-generic 5.15.149)
[    0.000000] Command line: vmlinuz_mega root=/dev/ram0 earlyprintk=serial,ttyS0,115200n8 console=ttyS0,115200n8 debug udev.event-timeout=5 loglevel=7
[    0.000000] KERNEL supported cpus:
[    0.000000]   Intel GenuineIntel
[    0.000000]   AMD AuthenticAMD
[    0.000000]   Hygon HygonGenuine
[    0.000000]   Centaur CentaurHauls
[    0.000000]   zhaoxin   Shanghai  
[    0.000000] BIOS-provided physical RAM map:
[    0.000000] BIOS-e820: [mem 0x0000000000000000-0x000000000009ffff] usable
......

But when I boot into a physical machine, my log stops at EFI stub message:

......
Filename: boot.ipxe
tftp://10.1.1.11/boot.ipxe... ok
boot.ipxe : 297 bytes [script]
"##########################ipxe script loaded!###########################"
http://10.1.1.11/vmlinuz_mega... ok
http://10.1.1.11/initramfs_std_mega.gz... ok 
vmlinuz_mega : 11671784 bytes [EFI] [SELECTED] "root=/dev/ram0 earlyprintk=serial,ttyS0,115200n8 console=ttyS0,115200n8 debug udev.event-timeout=5 loglevel=7"
initramfs_std_mega.gz : 223862353 bytes
EFI stub: Loaded initrd from LINUX_EFI_INITRD_MEDIA_GUID device path

Is there a config relating to this ?
I tried debug params but it doesn't work.
My kernel parameters are root=/dev/ram0 earlyprintk=serial,ttyS0,115200n8 console=ttyS0,115200n8 debug udev.event-timeout=5 loglevel=7

Thank you!

[NiKiZe]

At this stage iPXE has told firmware to execute the kernel, and the kernel has started, as seen by the EFI stub message from the kernel.

You need to debug the kernel, not iPXE.

Consider reducing your command line as much as possible, also remove the initrd until you get any output from the kernel.

[Slone123c]

Thank you!
After doing some researches, this is related to some console settings.
I added console=tty0 on the kernel parameter to print the kernel logs successfully.