On 4/1/2014 8:23 AM, Finn Thain wrote:
On Tue, 1 Apr 2014, Geert Uytterhoeven wrote:<snip> Don't know about Mac,It may be possible to boot Linux with MacOS running in 24-bit mode, and ISTR that this leads to a large number of memory chunks. The Penguin documentation says use 32-bit mode (which means installing Mode32 if you have old MacOS and old ROMs). The only Mac I have here is running MacOS 7.6 so I can't test 24-bit mode. You can see the debug output from Penguin below.
I happen to have my crazy PearPC/Mac OS X-booting LC475 still up and running with a 7.5.5 system folder on it. I rebooted it into 24-bit mode and loading Penguin does give a warning that 32-bit mode works better. Attempting to boot generates:
*** Too many memory ranges!!! Error: *** setup_ram_mappings() failure - too many mappingsI have a 64mb simm in this LC475; I tried popping it out (leaving me with 4mb) and it actually did attempt to unpack the kernel, but there's too little memory to do it. I have a bagful of smaller 72-pin simms kicking around somewhere; I'll have to dig it out of the closet and try it again.
Sadly my IIci is still misbehaving due to bad caps. I do have a working 840AV here... I believe it should work in 24-bit mode. I don't have any older 32-bit unclean Macs of the era when 24-bit was normal to try with to see if maybe the memory controller works better.
but I have some memories of interleaved banks and such...There are some Mac models with memory controllers that do interleaving. I don't know whether interleaving is relevant here. I'd have to consult the Penguin source code to know whether it behaves differently on different models.
All I can say here is I ran 2.0-era kernels on a Quadra 840AV which does have interleaved RAM way back in the day just fine. I haven't yet gotten modern kernels (even the setup that works on the LC475) booting on it yet; sadly I'm not much good for coding or debug tracing.
Scott