diff options
| -rw-r--r-- | hw/intc/armv7m_nvic.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c index 6ff6c7f0cc..ca19157c1e 100644 --- a/hw/intc/armv7m_nvic.c +++ b/hw/intc/armv7m_nvic.c @@ -77,6 +77,15 @@ static inline int64_t systick_scale(nvic_state *s) static void systick_reload(nvic_state *s, int reset) { + /* The Cortex-M3 Devices Generic User Guide says that "When the + * ENABLE bit is set to 1, the counter loads the RELOAD value from the + * SYST RVR register and then counts down". So, we need to check the + * ENABLE bit before reloading the value. + */ + if ((s->systick.control & SYSTICK_ENABLE) == 0) { + return; + } + if (reset) s->systick.tick = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); s->systick.tick += (s->systick.reload + 1) * systick_scale(s); |