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Re: Sun Leo (ZX)



Apologies for the delay and lousy threading- I lost the connection to the ML.

On Fri, 18 Apr 2008 14:40:13 +0200 Tom "spot" Callaway wrote:

>>> I think I could usefully put some printk()s in leo.c, but I need to
>>> sort out the disc before I have any chance of compiling that.
>>
>>I'm back on this and I've been having fun with printk()s. What I can
>>see is:
>>
>>[MarkMLl] Entered leo_init()
>>[MarkMLl] In leo_init(), matched option
>>[MarkMLl] Entered of_register_driver()
>>[MarkMLl] driver_register() -> 0
>>[MarkMLl] of_register_driver() -> 0
>>Console: switching to mono PROM 80x34
>>rtc_init: no PC rtc found
>>
>>I think that the return from driver_register() hence
>>of_register_driver() indicates success so leo_init() is OK, however I
>>don't see control being transferred into leo_probe().

>> What is the significance of the match check? I presume this is a
>> device
>> name but what is it tested against?
>
>If memory serves, its checking for that value in the openpromfs.
>
>~spot

After comparing various drivers I've patched leo.c to match against "SUNW,leofb" rather than just "leofb" and the driver is now loading. Unfortunately it crashes the machine almost immediately- I see "Booting Linux..." followed by a clear screen then it's in a totally unresponsive state. It's worth noting that it's a /fast/ clear screen, not the five seconds it took when the kernel had fallen back to the PROM for output, so I know it's the Leo driver doing it... progress :-)

That leaves me in a position where I can't see printk() output. I considered using prom_printf() which is how I got Linux running on my SS1000E, however I note that that's deprecated- how do I use the -p option that's supposed to flush printk() output to the console promptly?

I've tried various combinations of video=offb:on etc. but something that I haven't tracked down is overriding that- I suspect it might be SILO doing some well-meaning sanity checks. I'd add that in all of the above I've tried using a serial console to no advantage.

I suspect that what I need to do is put kernel 2.4 on the system and check whether it works, then compare a 2.6 driver with a 2.4 to get a list of required changes- are these documented anywhere?

I'll continue tinkering when I can find time but any guidance would be appreciated.

--
Mark Morgan Lloyd
markMLl .AT. telemetry.co .DOT. uk

[Opinions above are the author's, not those of his employers or colleagues]


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