Kernel log not printed to specified serial console

It seems the linux kernel does not print any log to specified console in the command line:

[    0.000000] Kernel command line: BOOT_IMAGE=(hd0,msdos2)/boot/vmlinuz-6.12.0-55.17.1.el10_0.aarch64 root=UUID=1fc4f77a-a45d-40e4-a434-76f4124d4872 ro audit=0 console=hvc0 ipv6.disable=1 mitigations=off se
linux=0 loglevel=7

The earliest log I can find is systemd:

[    2.084912] systemd[1]: systemd 257-9.el10_0.1-gf8a2760 running in system mode (+PAM +AUDIT +SELINUX -APPARMOR +IMA +IPE +SMACK +SECCOMP -GCRYPT -GNUTLS +OPENSSL +ACL +BLKID +CURL +ELFUTILS +FIDO2 +IDN2 -IDN -IPTC +KMOD +LIBCRYPTSETUP +LIBCRYPTSETUP_PLUGINS +LIBFDISK +PCRE2 +PWQUALITY +P11KIT -QRENCODE +TPM2 +BZIP2 +LZ4 +XZ +ZLIB +ZSTD +BPF_FRAMEWORK +BTF +XKBCOMMON +UTMP +SYSVINIT +LIBARCHIVE)
[    2.085117] systemd[1]: Detected virtualization apple.
[    2.085142] systemd[1]: Detected architecture arm64.

Why is that and how can I view the kernel log when boot?

It turns out the kernel does not have virtio_console built in. I guess there’s no luck to get it supported without reporting to RHEL.

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An alternative is use the ELREPO repository, and install either kernel-lt or kernel-ml. These are 6.x kernels and have the virtio_console module.

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