Description of problem:

Device is a Curtiss-Wright VPX6-196 SBC: https://www.curtisswrightds.com/products/computing/processors/6u-vpx/vpx6-1961

Datasheet: https://www.curtisswrightds.com/sites/default/files/2022-02/VPX6-1961-Intel-Xeon-W-Single-Board-Computer-product-sheet.pdf

The BIOS only supports MMIO-based serial ports.

Attempts to install in text mode over a serial port fail. It is still possible
to install using a monitor an a keyboard. After that, ttyS5 works as expected.

Version-Release number of selected component (if applicable):

RHEL 8.7 (rhel-8.7-x86_64-dvd.iso dumped to a USB stick)

How reproducible:

Always

Steps to Reproduce:
1. Boot from the RHEL 8.7 installation media using a serial terminal attaced
to the second serial port.

2. At the GRUB prompt, edit the kernel command line to force it to start an
early console on the required I/O address and to use ttyS1 later:

linuxefi /images/pxeboot/vmlinuz inst.stage2=hd:LABEL=RHEL-8-7-0-BaseOS-x86_64 console=uart,mmio32,0x6006353000,115200n8 console=ttyS1,115200 inst.text

3. Type Ctrl-X to start

Actual results:

Kernel messages stop being shown after this:

[ 0.000000] random: crng done (trusting CPU's manufacturer)
[ 0.001000] Console: colour dummy device 80x25

Expected results:

The serial port should become the system console and be used by Anaconda
to perform the installation.

Additional info:

At the installation, the srial ports are mapped to ttyS[0-3], according to the
anaconda log /var/log/anaconda/journal.log:

Jan 01 00:00:43 localhost kernel: dw-apb-uart.1: ttyS0 at MMIO 0x6006354000 (irq = 33, base_baud = 114825) is a 16550A
Jan 01 00:00:43 localhost kernel: dw-apb-uart.2: ttyS1 at MMIO 0x6006353000 (irq = 16, base_baud = 114825) is a 16550A
Jan 01 00:00:43 localhost kernel: dw-apb-uart.3: ttyS2 at MMIO 0x6006352000 (irq = 17, base_baud = 114825) is a 16550A

After the installation, they are mapped to ttyS[4-6]
Dec 31 19:54:33 localhost kernel: dw-apb-uart.1: ttyS4 at MMIO 0x6006354000 (irq = 33, base_baud = 114825) is a 16550A
Dec 31 19:54:33 localhost kernel: dw-apb-uart.2: ttyS5 at MMIO 0x6006353000 (irq = 16, base_baud = 114825) is a 16550A
Dec 31 19:54:33 localhost kernel: dw-apb-uart.3: ttyS6 at MMIO 0x6006352000 (irq = 17, base_baud = 114825) is a 16550A

Using ttyS5 at the installation does not make any difference.

Attaching a transcript of the serial console during the attempt to install over
the serial port.

Attaching an sosreport generated after installing the system using minitor and keyboard.
--------Unable to render embedded object: File (---------) not found.-------Unable to render embedded object: File (---------) not found.-------Unable to render embedded object: File (---------) not found.--------Unable to render embedded object: File (---------) not found.