Re: Plea for help from PowerMac Open Firmware gurus -- Testing newoldworld pmac miboot 2.6 floppies
> Well... on the beige G3, I booted into Open Firmware with the
> "ofonlyboot" floppy in the drive. The G3 comes up with console
> input/output being keyboard/screen. From another Mac running MacOS-9, I
> connected with MacKermit to the G3's modem port (which is normally
> "/dev/ttyS0" under Linux)
> At the G3's console, I typed "boot console=ttyS0<return>". The floppy
> drive made reading noises, and the "tuxMac" icon appeared on the G3's
> screen. Nothing happened at this point on the Kermit serial port --
> there was no response when I type things at it over the serial port.
> After a while the floppy stopped making noises and a red "X" appeared
> over the tuxMac icon. Still no messages on the serial port, but now it
> at least will echo what I type at it. No response other than echos,
> though. It seems that I'm not talking to a live kernel.
> Does any one have a clue what the red "X" means?
> It appears that the "console=ttyS0" option is being noticed (at least
> that's how I interpret the fact that it switched from no-echo to echo at
> the point where the red "X" appeared...) So I could put other boot-time
> options there as well. Is there a "verbose" option I can try?
1) Reading man pages for "bootparam" seems to indicate that there is a "debug" boot parameter that turns on more verbose logging to the console. Unfortunately, when I tried it with the 2.6 boot floppy, there was no change from the above described behavior.
2) For comparison purposes, I tried the same thing with the 2.4 "powerpc-small" boot floppy. (the 2.4 root floppy is hosed, so I didn't expect to get very far, but...)
I booted the G3 into Open Firmware while listening to the modem serial port on another machine -- as described above. On the G3's console, I typed "boot debug console=ttyS0<return>". I was rewarded by a tuxmac icon and floppy reading noises. When the noises stopped, the kernel boot messages appeared on the G3's console screen, but nothing appered at the remote terminal watching the serial port.
So I'm no longer so sure as I once was that the parameters after "boot" in Open Firmware are getting passed to the kernel. Is it possible to modify the boot-parameters that are compiled into the kernel? For example, the "ofonlyboot" kernel differs from the "boot" kernel only in that there is a string "video=ofonly" in the former, but not in the latter. How does that get there? Maybe the same mechanism could be used to give it the "debug" and "console=ttyS0" options...