Add CPU unassigned access handler in place of special
MemoryRegion to catch exception returns.
Signed-off-by: Michael Davidsaver <mdavidsa...@gmail.com>
---
hw/arm/armv7m.c | 8 --------
target-arm/cpu.c | 18 ++++++++++++++++++
2 files changed, 18 insertions(+), 8 deletions(-)
diff --git a/hw/arm/armv7m.c b/hw/arm/armv7m.c
index a80d2ad..68146de 100644
--- a/hw/arm/armv7m.c
+++ b/hw/arm/armv7m.c
@@ -176,7 +176,6 @@ DeviceState *armv7m_init(MemoryRegion *system_memory, int
mem_size, int num_irq,
uint64_t entry;
uint64_t lowaddr;
int big_endian;
- MemoryRegion *hack = g_new(MemoryRegion, 1);
if (cpu_model == NULL) {
cpu_model = "cortex-m3";
@@ -221,13 +220,6 @@ DeviceState *armv7m_init(MemoryRegion *system_memory, int
mem_size, int num_irq,
}
}
- /* Hack to map an additional page of ram at the top of the address
- space. This stops qemu complaining about executing code outside RAM
- when returning from an exception. */
- memory_region_init_ram(hack, NULL, "armv7m.hack", 0x1000, &error_fatal);
- vmstate_register_ram_global(hack);
- memory_region_add_subregion(system_memory, 0xfffff000, hack);
-
qemu_register_reset(armv7m_reset, cpu);
return nvic;
}
diff --git a/target-arm/cpu.c b/target-arm/cpu.c
index 30739fc..be026bc 100644
--- a/target-arm/cpu.c
+++ b/target-arm/cpu.c
@@ -280,6 +280,23 @@ bool arm_cpu_exec_interrupt(CPUState *cs, int
interrupt_request)
}
#if !defined(CONFIG_USER_ONLY) || !defined(TARGET_AARCH64)
+static void arm_v7m_unassigned_access(CPUState *cpu, hwaddr addr,
+ bool is_write, bool is_exec, int opaque,
+ unsigned size)
+{
+ ARMCPU *arm = ARM_CPU(cpu);
+ CPUARMState *env = &arm->env;
+
+ if (env->v7m.exception != 0 && addr >= 0xfffffff0 && !is_write) {
+ cpu->exception_index = EXCP_EXCEPTION_EXIT;
+ cpu_loop_exit(cpu);
+ } else {
+ /* TODO, signal some *Fault? */
+ cpu_abort(cpu, "Trying to access outside RAM or ROM at 0x"
+ TARGET_FMT_plx "\n", addr);
+ }
+}
+
static bool arm_v7m_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
{
CPUClass *cc = CPU_GET_CLASS(cs);
@@ -909,6 +926,7 @@ static void arm_v7m_class_init(ObjectClass *oc, void *data)
cc->do_interrupt = arm_v7m_cpu_do_interrupt;
#endif
+ cc->do_unassigned_access = arm_v7m_unassigned_access;
cc->cpu_exec_interrupt = arm_v7m_cpu_exec_interrupt;
}
--
2.1.4
