Re: kernel goes dark on boot

[Emmanuel Dreyfus <manu%netbsd.org@localhost>]

On Wed, Jan 11, 2023 at 08:30:20AM +0000, Emmanuel Dreyfus wrote:
> An interesting problem on an all-in-one HP PC. Booting
> NetBSD-10.0_BETA/amd64 (or prior versions) works fine until the
> kernel starts displaying its messages. At that point the screen
> turns dark.

I patched bootx64.efi to comment out the vbe_commit() call, 
the screen does not go dark, but system still crashes. 

By commenting out the uefi_call_wrapper() for ExitBootServices
I can printf up to the startprog64() call, then the bootstrap 
jump into assembly code, and it is much more difficult 
to figure what is going on. All I can say is that startprog64()
arguments do not look insane.

I am looking for debug hints. Is there some sample code somewhere
that calls UEFI Print method from assembly? Any other suggestion?

-- 
Emmanuel Dreyfus
manu%netbsd.org@localhost