Tests on real Q800 hardware show that the ESCC is addressable at multiple
locations
within the ESCC memory region - at least 0xc000, 0xc020 (as expected by the
MacOS
toolbox ROM) and 0xc040.
All released NetBSD kernels before 10 use the 0xc000 address which causes a
fatal
error when running the MacOS booter. Add a single memory region alias at 0xc000
to enable NetBSD kernels to start booting under QEMU.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
---
hw/m68k/q800.c | 6 ++++++
include/hw/m68k/q800.h | 1 +
2 files changed, 7 insertions(+)
diff --git a/hw/m68k/q800.c b/hw/m68k/q800.c
index 5ae7c37760..b5b2cabc33 100644
--- a/hw/m68k/q800.c
+++ b/hw/m68k/q800.c
@@ -451,6 +451,12 @@ static void q800_machine_init(MachineState *machine)
memory_region_add_subregion(&m->macio, SCC_BASE - IO_BASE,
sysbus_mmio_get_region(sysbus, 0));
+ /* Create alias for NetBSD */
+ memory_region_init_alias(&m->escc_alias, OBJECT(machine), "escc-alias",
+ sysbus_mmio_get_region(sysbus, 0), 0, 0x8);
+ memory_region_add_subregion(&m->macio, SCC_BASE - IO_BASE - 0x20,
+ &m->escc_alias);
+
/* SCSI */
object_initialize_child(OBJECT(machine), "esp", &m->esp,
diff --git a/include/hw/m68k/q800.h b/include/hw/m68k/q800.h
index fbaacd88bd..348eaf4703 100644
--- a/include/hw/m68k/q800.h
+++ b/include/hw/m68k/q800.h
@@ -67,6 +67,7 @@ struct Q800MachineState {
MemoryRegion macio;
MemoryRegion macio_alias;
MemoryRegion machine_id;
+ MemoryRegion escc_alias;
};
#define TYPE_Q800_MACHINE MACHINE_TYPE_NAME("q800")