feat(ps2_uart): Enable EE UART

[XavierBrassoud]

Here is my contribution for this awesome project, thanks you Fredrik!
Happy new year to the PS2 Linux Community! 🎆

Description

Enable UART to the PS2 Emotional Engine (EE) serial port using ps2_uart module

• Console access: /dev/ttyS0 – baud rate: 38400
• Printk early kernel debug messages

Only polling mode is currently supported.

Fix #68
Associated PR: frno7/gentoo-mipsr5900el#22

Menu Config

Enable console access:

  │ Symbol: SERIAL_PS2_UART [=y]                                                                                                                                                       │  
  │ Type  : tristate                                                                                                                                                                   │  
  │ Prompt: PS2 serial port                                                                                                                                                            │  
  │   Location:                                                                                                                                                                        │  
  │     -> Device Drivers                                                                                                                                                              │  
  │       -> Character devices                                                                                                                                                         │  
  │         -> Serial drivers                                                                                                                                                          │  
  │                                                                                                                                                                                    │  
  │                                                                                                                                                                                    │  
  │ Symbol: SERIAL_PS2_UART_CONSOLE [=y]                                                                                                                                               │  
  │ Type  : bool                                                                                                                                                                       │  
  │ Prompt: PS2 serial port console                                                                                                                                                    │  
  │   Location:                                                                                                                                                                        │  
  │     -> Device Drivers                                                                                                                                                              │  
  │       -> Character devices                                                                                                                                                         │  
  │         -> Serial drivers                                                                                                                                                          │  
  │           -> PS2 serial port (SERIAL_PS2_UART [=y])

Enable debug early kernel printk messages:

  │ Symbol: CMDLINE [=video=AV-MULTI-OUT:1920x1080@50 console=tty0 console=tty1]                                                                                                         │  
  │ Type  : string                                                                                                                                                                     │  
  │ Prompt: Default kernel command string                                                                                                                                              │  
  │   Location:                                                                                                                                                                        │  
  │     -> Kernel hacking                                                                                                                                                              │  
  │       -> Built-in kernel command line (CMDLINE_BOOL [=y]) 

Tests

Real Hardware

screen /dev/ttyUSB0 38400

PCSX2

References

• Fix Enable EE UART #68
• initramfs including the support of UART console: feat(ps2_uart): Enable EE UART gentoo-mipsr5900el#22

[frno7]

Many thanks, @XavierBrassoud! It looks my Github compilation workflow script isn’t quite working with pull request actions though:

   LD      vmlinuz
  STRIP	  vmlinuz
ln: failed to create hard link 'vmlinuz-ntsc-88/merge-a6ec171c.elf' => 'vmlinuz': No such file or directory
Error: Process completed with exit code 1.

It does not seem to be a problem with your code. I should fix the Github workflow action script to make it work. :-)

[frno7]

Please review enclosed comments. Also,

• Would you like to add a tag Signed-off-by: Xavier Brassoud <xavier.brassoud@gmail.com> to your commit message?
• If you rebase your pull request on ps2-main (updated this morning) having commit f30d2c4, we should have the workflow action working with pull requests, hopefully. :-)

[DCFUKSURMOM]

This is awesome, especially having proper output on PCSX2, which was something I was curious about in the past

[XavierBrassoud]

Thanks you for your review :)

I have rebase and squash my commits into one with the tag Signed-off-by: Xavier Brassoud <xavier.brassoud@gmail.com> and tested following your recommendations.

If you see any new suggestions to make, I'll be happy to add them ;)

[frno7]

Great! The workflow action was happy to accept a pull request too. Merged in 515fa87. Thanks, @XavierBrassoud!