From: Gihun Nam <gihun.nam@outlook.com>

The current implementation initializes the stack pointer of AVR devices
to 0. Although older AVR devices used to be like that, newer ones set
it to RAMEND.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1525
Signed-off-by: Gihun Nam <gihun.nam@outlook.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <PH0P222MB0010877445B594724D40C924DEBDA@PH0P222MB0010.NAMP222.PROD.OUTLOOK.COM>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 target/avr/cpu.h |  3 +++
 hw/avr/atmega.c  |  4 ++++
 target/avr/cpu.c | 10 +++++++++-
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/target/avr/cpu.h b/target/avr/cpu.h
index 8a17862737..7960c5c57a 100644
--- a/target/avr/cpu.h
+++ b/target/avr/cpu.h
@@ -145,6 +145,9 @@ struct ArchCPU {
     CPUState parent_obj;
 
     CPUAVRState env;
+
+    /* Initial value of stack pointer */
+    uint32_t init_sp;
 };
 
 /**
diff --git a/hw/avr/atmega.c b/hw/avr/atmega.c
index a34803e642..31c8992d75 100644
--- a/hw/avr/atmega.c
+++ b/hw/avr/atmega.c
@@ -233,6 +233,10 @@ static void atmega_realize(DeviceState *dev, Error **errp)
 
     /* CPU */
     object_initialize_child(OBJECT(dev), "cpu", &s->cpu, mc->cpu_type);
+
+    object_property_set_uint(OBJECT(&s->cpu), "init-sp",
+                             mc->io_size + mc->sram_size - 1, &error_abort);
+
     qdev_realize(DEVICE(&s->cpu), NULL, &error_abort);
     cpudev = DEVICE(&s->cpu);
 
diff --git a/target/avr/cpu.c b/target/avr/cpu.c
index 44de1e18d1..999c010ded 100644
--- a/target/avr/cpu.c
+++ b/target/avr/cpu.c
@@ -25,6 +25,7 @@
 #include "cpu.h"
 #include "disas/dis-asm.h"
 #include "tcg/debug-assert.h"
+#include "hw/qdev-properties.h"
 
 static void avr_cpu_set_pc(CPUState *cs, vaddr value)
 {
@@ -95,7 +96,7 @@ static void avr_cpu_reset_hold(Object *obj)
     env->rampY = 0;
     env->rampZ = 0;
     env->eind = 0;
-    env->sp = 0;
+    env->sp = cpu->init_sp;
 
     env->skip = 0;
 
@@ -152,6 +153,11 @@ static void avr_cpu_initfn(Object *obj)
                       sizeof(cpu->env.intsrc) * 8);
 }
 
+static Property avr_cpu_properties[] = {
+    DEFINE_PROP_UINT32("init-sp", AVRCPU, init_sp, 0),
+    DEFINE_PROP_END_OF_LIST()
+};
+
 static ObjectClass *avr_cpu_class_by_name(const char *cpu_model)
 {
     ObjectClass *oc;
@@ -228,6 +234,8 @@ static void avr_cpu_class_init(ObjectClass *oc, void *data)
 
     device_class_set_parent_realize(dc, avr_cpu_realizefn, &mcc->parent_realize);
 
+    device_class_set_props(dc, avr_cpu_properties);
+
     resettable_class_set_parent_phases(rc, NULL, avr_cpu_reset_hold, NULL,
                                        &mcc->parent_phases);
 
-- 
2.41.0