Re: Macintosh Quadra 950 Not Booting
On Thu, 6 Aug 2015, Greg Andrzejewski wrote:
> Greetings,
>
> After finally getting my Mac SE/30 working again, I set about trying to
> get a modern version of Linux installed on the little fellow. Early
> experiments with 3.14 kernels were successful
BTW, are you using mac_scsi on the SE/30?
> and when a trio of Quadra 950s appeared on the local craigslist, I
> picked them up, looking forward to a more powerful 68k machine. Problem
> is I can't get any recent kernel to boot.
I haven't booted a Q950 for some years, but it should work.
Using Penguin, I did boot Linux 3.1 on a Quadra 700 which is somewhat
similar hardware. The only other report I found on the list about a Q950
was for Linux 2.6.20.
If you would like, I can send you a current kernel binary that should boot
any Mac (that is, SE/30 or Quadra 950).
Also, any debian kernel binary from 3.x or 4.x should give useful results.
(Kernel modules aren't relevant to isolating the cause of an early crash.)
>
> I've tried using Penguin-19 on MacOS 7.1 and 7.5.3 with identical
> results; the machine just hangs on the "Bootling Linux" message. The
> screen never clears, nothing even comes across the serial port with
> earlyprintk.
Penguin has a known bug in its zlib code that can cause kernel
decompression to fail like that. Is this a large debian kernel binary?
I suggest you try booting the vmlinux, e.g.
# gzip -dc < vmlinuz > vmlinux
I use Penguin with MacOS 7.5.3 without any issues; however, you might want
to try with extensions disabled (hold down <shift> when you hear the
chime) to avoid a possible unhandled slot interrupt during early boot.
> I installed MacsBug in hopes of finding something useful in __log_buf on
> reboot, but the entire buffer is empty (zeros). I'd suspect the
> bootloader is at fault, but Penguin successfully boots a 4.0.0 kernel on
> my SE/30. Penguin log is attached, in case anyone's interested.
I don't know anything about __log_buf. I suspect you'd need to avoid the
POST memory test for that to work.
>
> Still not 100% confident in Penguin, I tried booting with an EMILE
> rescue disk. EMILE reads the kernel from disk and shortly thereafter the
> chimes of death play (!!!!). Is this something the kernel can
> intentionally do or is it more likely sort sort of triple fault-like
> situation?
I've never tried EMILE on my Q950. Perhaps Laurent can speak to that.
>
> I've done a touch of kernel debugging, but this was on x86 and never
> this early in the boot process. What next steps can I take to further
> debug this issue?
The first thing you should see is the output from the early boot code:
"ABCFGHIJK". If you don't see that then likely causes are an unhandled
early interrupt or bootloader bug.
However, it is also possible that a recent commit has messed up the OSS
driver:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/arch/m68k/mac?id=b24f670b7f5b2058b95370caa9f104b3cefb9f1d
But this first appeared in v4.1, so it probably isn't relevant.
> I've glanced at the early arch code, but all I really got out of it was
> a few chuckles from the comments venting about Apple's, uh, peculiar
> hardware design.
I suspect that the resentment of kernel developers would have been minimal
had Apple made more documentation public. Unlike the authors of those
comments, I don't blame Apple engineers for its corporate policies.
Finn
>
> Thanks,
> Greg
>
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