On Sat, 14 Dec 2019, John Paul Adrian Glaubitz wrote: > Hi! > > When installing Debian/m68k inside qemu-m68k-system [1], we are > currently limited to 1 GB of physical memory which is due to a limit in > the Linux kernel as far as I know. > > However, I also know that it is possible to run the m68k kernel on > Aranym with up to 3.5 GB of RAM. Thus, I was wondering whether there > would be chance we could get the kernel patched to support more than 1 > GB of memory also on qemu-m68k-system which currently emulates an Apple > Macintosh Quadra 800 system. > > Adrian > > > [1] https://wiki.debian.org/M68k/QemuSystemM68k >
I believe that the reason for the limitation is the Mac memory map, as Laurent pointed out in the issue tracker, https://github.com/vivier/qemu-m68k/issues/42 It's theoretically possible to use NuBus slot space for additional RAM. The super slot space ($6000 0000 thru $EFFF FFFF) is 2304 MB in size and the standard slot space ($F100 0000 thru $FFFF FFFF) is another 239 MB. I'm not sure about any hardware designs that took advantage of this possibility (Radius Rocket perhaps?). --
