Add optional support for real-time clint

This patch adds optional support clint timer incrementing at
real-time rate. This can be enabled by passing command line
parameter "--real-time-clint".

This feature can be used for:
1. Checking whether any code addition to Spike is slowing down
simulation too much
2. Comparing run-time for software on Spike with other functional
simulators (such as QEMU)

Signed-off-by: Anup Patel <anup.patel@wdc.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/riscv/devices.h b/riscv/devices.h
index aa4c050..130be3c 100644
--- a/riscv/devices.h
+++ b/riscv/devices.h
@@ -63,7 +63,7 @@ class mem_t : public abstract_device_t {
 
 class clint_t : public abstract_device_t {
  public:
-  clint_t(std::vector<processor_t*>&);
+  clint_t(std::vector<processor_t*>&, uint64_t freq_mhz, bool real_time);
   bool load(reg_t addr, size_t len, uint8_t* bytes);
   bool store(reg_t addr, size_t len, const uint8_t* bytes);
   size_t size() { return CLINT_SIZE; }
@@ -73,6 +73,10 @@ class clint_t : public abstract_device_t {
   typedef uint64_t mtimecmp_t;
   typedef uint32_t msip_t;
   std::vector<processor_t*>& procs;
+  uint64_t freq_mhz;
+  bool real_time;
+  uint64_t real_time_ref_secs;
+  uint64_t real_time_ref_usecs;
   mtime_t mtime;
   std::vector<mtimecmp_t> mtimecmp;
 };