[Qemu-devel] [PATCH 1/2] debugexit: support for custom exit port (e.g LGPL'ed VGA BIOS port 0x501)

["Hervé Poussineau" <hpoussin@reactos.org>]

Add generic support for simple I/O port which, when written to, cause
QEMU to exit with the given written value.

There is no vmstate associated with the debugging port, simply because
the entire interface is a single, stateless, write-only port.

Signed-off-by: Hervé Poussineau <hpoussin@reactos.org>
---
 hw/debugexit.c        |   68 +++++++++++++++++++++++++++++++++++++++++++++++++
 hw/i386/Makefile.objs |    2 +-
 2 files changed, 69 insertions(+), 1 deletion(-)
 create mode 100644 hw/debugexit.c

diff --git a/hw/debugexit.c b/hw/debugexit.c
new file mode 100644
index 0000000..72ddf31
--- /dev/null
+++ b/hw/debugexit.c
@@ -0,0 +1,68 @@
+/*
+ * QEMU debug exit port ("LGPL'ed-VGA-BIOS-style port 501/502") emulation
+ *
+ * Copyright (c) 2012 Herve Poussineau
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "isa.h"
+
+typedef struct ISADebugExitState {
+    ISADevice dev;
+    uint32_t iobase;
+    uint8_t access_size;
+} ISADebugExitState;
+
+static void debugexit_ioport_write(void *opaque, uint32_t addr, uint32_t val)
+{
+    exit((val << 1) | 1);
+}
+
+static int debugexit_isa_initfn(ISADevice *dev)
+{
+    ISADebugExitState *isa = DO_UPCAST(ISADebugExitState, dev, dev);
+
+    register_ioport_write(isa->iobase, 1, isa->access_size,
+                          debugexit_ioport_write, NULL);
+    return 0;
+}
+
+static Property debugexit_isa_properties[] = {
+    DEFINE_PROP_HEX32("iobase", ISADebugExitState, iobase, 0x501),
+    DEFINE_PROP_UINT8("access-size", ISADebugExitState, access_size, 1),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void debugexit_isa_class_initfn(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    ISADeviceClass *ic = ISA_DEVICE_CLASS(klass);
+    ic->init = debugexit_isa_initfn;
+    dc->props = debugexit_isa_properties;
+}
+
+static TypeInfo debugexit_isa_info = {
+    .name          = "isa-debugexit",
+    .parent        = TYPE_ISA_DEVICE,
+    .instance_size = sizeof(ISADebugExitState),
+    .class_init    = debugexit_isa_class_initfn,
+};
+
+static void debugexit_register_types(void)
+{
+    type_register_static(&debugexit_isa_info);
+}
+
+type_init(debugexit_register_types)
diff --git a/hw/i386/Makefile.objs b/hw/i386/Makefile.objs
index eb171b7..23be2d3 100644
--- a/hw/i386/Makefile.objs
+++ b/hw/i386/Makefile.objs
@@ -3,7 +3,7 @@ obj-y += apic_common.o apic.o kvmvapic.o
 obj-y += sga.o ioapic_common.o ioapic.o piix_pci.o
 obj-y += vmport.o
 obj-y += pci-hotplug.o smbios.o wdt_ib700.o
-obj-y += debugcon.o multiboot.o
+obj-y += debugcon.o debugexit.o multiboot.o
 obj-y += pc_piix.o
 obj-y += pc_sysfw.o
 obj-$(CONFIG_XEN) += xen_platform.o xen_apic.o
-- 
1.7.10