[PATCH] hw/arm: Add 'virtm' hardware

[Keith Packard]

'virtm' is a hardware target that is designed to be used for compiler
and library testing on Cortex-M processors. It supports all cortex-m
processors and includes sufficient memory to run even large test
cases.

Signed-off-by: Keith Packard <keithp@keithp.com>
---
 MAINTAINERS          |   9 +++-
 hw/arm/Makefile.objs |   2 +-
 hw/arm/virtm.c       | 112 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 121 insertions(+), 2 deletions(-)
 create mode 100644 hw/arm/virtm.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 1b40446c73..4c7e394dd6 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -850,9 +850,16 @@ Virt
 M: Peter Maydell <peter.maydell@linaro.org>
 L: qemu-arm@nongnu.org
 S: Maintained
-F: hw/arm/virt*
+F: hw/arm/virt.c
+F: hw/arm/virt-acpi-build.c
 F: include/hw/arm/virt.h
 
+Virt M
+M: Keith Packard <keithp@keithp.com>
+L: qemu-arm@nongnu.org
+S: Maintained
+F: hw/arm/virtm.c
+
 Xilinx Zynq
 M: Edgar E. Iglesias <edgar.iglesias@gmail.com>
 M: Alistair Francis <alistair@alistair23.me>
diff --git a/hw/arm/Makefile.objs b/hw/arm/Makefile.objs
index 534a6a119e..54be15b40a 100644
--- a/hw/arm/Makefile.objs
+++ b/hw/arm/Makefile.objs
@@ -1,6 +1,6 @@
 obj-y += boot.o
 obj-$(CONFIG_PLATFORM_BUS) += sysbus-fdt.o
-obj-$(CONFIG_ARM_VIRT) += virt.o
+obj-$(CONFIG_ARM_VIRT) += virt.o virtm.o
 obj-$(CONFIG_ACPI) += virt-acpi-build.o
 obj-$(CONFIG_DIGIC) += digic_boards.o
 obj-$(CONFIG_EXYNOS4) += exynos4_boards.o
diff --git a/hw/arm/virtm.c b/hw/arm/virtm.c
new file mode 100644
index 0000000000..beda3644f5
--- /dev/null
+++ b/hw/arm/virtm.c
@@ -0,0 +1,112 @@
+/*
+ * Virtual ARM Cortex M
+ *
+ * Copyright © 2020, Keith Packard <keithp@keithp.com>
+ *
+ * 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, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "hw/arm/boot.h"
+#include "hw/boards.h"
+#include "exec/address-spaces.h"
+#include "hw/arm/armv7m.h"
+#include "hw/misc/unimp.h"
+#include "cpu.h"
+
+#define NUM_IRQ_LINES 32
+#define ROM_BASE  0x00000000
+#define ROM_SIZE  0x20000000
+#define RAM_BASE    0x20000000
+#define RAM_SIZE    0x20000000
+
+static const char *valid_cpus[] = {
+    ARM_CPU_TYPE_NAME("cortex-m0"),
+    ARM_CPU_TYPE_NAME("cortex-m3"),
+    ARM_CPU_TYPE_NAME("cortex-m33"),
+    ARM_CPU_TYPE_NAME("cortex-m4"),
+    ARM_CPU_TYPE_NAME("cortex-m7"),
+};
+
+static bool cpu_type_valid(const char *cpu)
+{
+    int i;
+
+    return true;
+    for (i = 0; i < ARRAY_SIZE(valid_cpus); i++) {
+        if (strcmp(cpu, valid_cpus[i]) == 0) {
+            return true;
+        }
+    }
+    return false;
+}
+
+static void machvirtm_init(MachineState *ms)
+{
+    DeviceState *nvic;
+
+    if (!cpu_type_valid(ms->cpu_type)) {
+        error_report("virtm: CPU type %s not supported", ms->cpu_type);
+        exit(1);
+    }
+
+    MemoryRegion *ram = g_new(MemoryRegion, 1);
+    MemoryRegion *rom = g_new(MemoryRegion, 1);
+    MemoryRegion *system_memory = get_system_memory();
+
+    /* Flash programming is done via the SCU, so pretend it is ROM.  */
+    memory_region_init_rom(rom, NULL, "virtm.rom", ROM_SIZE,
+                           &error_fatal);
+    memory_region_add_subregion(system_memory, ROM_BASE, rom);
+
+    memory_region_init_ram(ram, NULL, "virtm.ram", RAM_SIZE,
+                           &error_fatal);
+    memory_region_add_subregion(system_memory, RAM_BASE, ram);
+
+    nvic = qdev_new(TYPE_ARMV7M);
+    qdev_prop_set_uint32(nvic, "num-irq", NUM_IRQ_LINES);
+    qdev_prop_set_string(nvic, "cpu-type", ms->cpu_type);
+    qdev_prop_set_bit(nvic, "enable-bitband", true);
+    object_property_set_link(OBJECT(nvic), OBJECT(get_system_memory()),
+                                     "memory", &error_abort);
+    /* This will exit with an error if the user passed us a bad cpu_type */
+    sysbus_realize_and_unref(SYS_BUS_DEVICE(nvic), &error_fatal);
+
+    armv7m_load_kernel(ARM_CPU(first_cpu), ms->kernel_filename, ROM_SIZE);
+}
+
+static void virtm_class_init(ObjectClass *oc, void *data)
+{
+    MachineClass *mc = MACHINE_CLASS(oc);
+
+    mc->desc = "Virtual Cortex-M";
+    mc->init = machvirtm_init;
+    mc->ignore_memory_transaction_failures = true;
+    mc->default_cpu_type = ARM_CPU_TYPE_NAME("cortex-m3");
+}
+
+static const TypeInfo virtm_type = {
+    .name = MACHINE_TYPE_NAME("virtm"),
+    .parent = TYPE_MACHINE,
+    .class_init = virtm_class_init,
+};
+
+static void virtm_machine_init(void)
+{
+    type_register_static(&virtm_type);
+}
+
+type_init(virtm_machine_init)
-- 
2.27.0