Re: More serial ports in EFI bootstrap?

On Tue, Jun 17, 2025 at 03:41:15PM +0100, Robert Swindells wrote:
> Start at the 'struct consdev comcons' declaration, that links to the
> functions needed.

I made some progress. When booting with consdev=ucom,0,115200, 
ucom0 attaches the console when ucom_attach() is called.

Here is the code so far:
https://dl.espci.fr/ticket/cf60ed7e55d22201404446e3fc3f0544

I did not include the efiboot part, which is still a bit messy.

There are three problems:

1.system freeze shortly after reaching multiuser. I have been 
  able to get a panic once: spec_close() was unhappy about an
  open count. I suspect the call to ucomopen() in ucom_attach()
  is the culprit. Comments welcome

2.I cannot get a getty to open /dev/ttyU0. ktrace says:
  5347   5347 getty    CALL  open(0xab24e0,2,0xfffffffffffff5a8)
  5347   5347 getty    NAMI  "/dev/ttyU0"
  5347   5347 getty    RET   open RESTART
  5347   5347 getty    CALL  open(0xab24e0,2,0xfffffffffffff5a8)
  5347   5347 getty    NAMI  "/dev/ttyU0"
  5347   5347 getty    RET   open RESTART
  5347   5347 getty    CALL  open(0xab24e0,2,0xfffffffffffff5a8)
  5347   5347 getty    NAMI  "/dev/ttyU0"
  5347   5347 getty    RET   open RESTART

3.No way to break into DDB. What did I do wrong? 

-- 
Emmanuel Dreyfus
[email protected]