Linux kernel boot fails when trying to use more than 1000MB of memory (i.e. 1024MB) about qemu-m68k HOT 4 CLOSED

RAM is mapped between 0 and 0x3fffffff, so the maximum is 1024 Mib,
ROM is between 0x40000000 and 0x4fffffff,
I/O starts at 0x5000000, which is 1280 MiB and explains the assertion crash.

So we may limit to 1024 MiB at QEMU level.
I don't know why we can't use the last 24 MiB, but I suspect a problem in the kernel.

from qemu-m68k.

We have an hint in the kernel logs:

ABCFGHIJK
Linux version 5.4.0-rc4-mac-17620-g8d7828aa2b90 (laurent@quad) (gcc version 9.2.1 20190827 (Red Hat Cross 9.2.1-1) (GCC)) #31 Fri Oct 25 18:35:50 CEST 2019
Saving 128 bytes of bootinfo
Detected Macintosh model: 35
Apple Macintosh Quadra 800
Built 1 zonelists, mobility grouping on.  Total pages: 259840

259840 * 4 kiB / 1 MiB = 1015 MiB

from qemu-m68k.

@vivier I think we can close this issue now as this is a hardware limitation, nothing that qemu can change if it emulates a Quadra 800. And since we have the new m68k-virt machine that allows up to 3.2 GB of RAM, the RAM size limitation no longer exists in qemu-m68k.

from qemu-m68k.

@vivier I think we can close this issue now as this is a hardware limitation, nothing that qemu can change if it emulates a Quadra 800. And since we have the new m68k-virt machine that allows up to 3.2 GB of RAM, the RAM size limitation no longer exists in qemu-m68k.

Yes, and moreover I think the bug is in the kernel

from qemu-m68k.