From 90bafe660b323250338fd564bb9ab4316576d59b Mon Sep 17 00:00:00 2001
From: Tim Newsome <tim@sifive.com>
Date: Fri, 16 Mar 2018 14:52:09 -0700
Subject: [PATCH] Implement debug havereset bits

---
 riscv/debug_module.cc | 14 ++++++++++++++
 riscv/debug_module.h  |  8 +++++++-
 riscv/processor.cc    |  2 ++
 riscv/sim.cc          |  5 +++++
 riscv/sim.h           |  5 +++++
 5 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/riscv/debug_module.cc b/riscv/debug_module.cc
index 74c3023..6f9359b 100644
--- a/riscv/debug_module.cc
+++ b/riscv/debug_module.cc
@@ -35,6 +35,7 @@ debug_module_t::debug_module_t(sim_t *sim, unsigned progbufsize, unsigned max_bu
   memset(halted, 0, sizeof(halted));
   memset(debug_rom_flags, 0, sizeof(debug_rom_flags));
   memset(resumeack, 0, sizeof(resumeack));
+  memset(havereset, 0, sizeof(havereset));
   memset(program_buffer, 0, program_buffer_bytes);
   program_buffer[4*progbufsize] = ebreak();
   program_buffer[4*progbufsize+1] = ebreak() >> 8;
@@ -387,6 +388,10 @@ bool debug_module_t::dmi_read(unsigned address, uint32_t *value)
 
           result = set_field(result, DMI_DMSTATUS_IMPEBREAK,
               dmstatus.impebreak);
+          result = set_field(result, DMI_DMSTATUS_ALLHAVERESET,
+              havereset[dmcontrol.hartsel]);
+          result = set_field(result, DMI_DMSTATUS_ANYHAVERESET,
+              havereset[dmcontrol.hartsel]);
 	  result = set_field(result, DMI_DMSTATUS_ALLNONEXISTENT, dmstatus.allnonexistant);
 	  result = set_field(result, DMI_DMSTATUS_ALLUNAVAIL, dmstatus.allunavail);
 	  result = set_field(result, DMI_DMSTATUS_ALLRUNNING, dmstatus.allrunning);
@@ -664,6 +669,9 @@ bool debug_module_t::dmi_write(unsigned address, uint32_t value)
             dmcontrol.ndmreset = get_field(value, DMI_DMCONTROL_NDMRESET);
             dmcontrol.hartsel = get_field(value, ((1L<<hartsellen)-1) <<
                 DMI_DMCONTROL_HARTSEL_OFFSET);
+            if (get_field(value, DMI_DMCONTROL_ACKHAVERESET)) {
+              havereset[dmcontrol.hartsel] = false;
+            }
           }
           processor_t *proc = current_proc();
           if (proc) {
@@ -755,3 +763,9 @@ bool debug_module_t::dmi_write(unsigned address, uint32_t value)
   }
   return false;
 }
+
+void debug_module_t::proc_reset(unsigned id)
+{
+  havereset[id] = true;
+  halted[id] = false;
+}
diff --git a/riscv/debug_module.h b/riscv/debug_module.h
index 813c647..50107fc 100644
--- a/riscv/debug_module.h
+++ b/riscv/debug_module.h
@@ -19,6 +19,8 @@ typedef struct {
 
 typedef struct {
   bool impebreak;
+  bool allhavereset;
+  bool anyhavereset;
   bool allnonexistant;
   bool anynonexistant;
   bool allunavail;
@@ -95,6 +97,9 @@ class debug_module_t : public abstract_device_t
     bool dmi_read(unsigned address, uint32_t *value);
     bool dmi_write(unsigned address, uint32_t value);
 
+    // Called when one of the attached harts was reset.
+    void proc_reset(unsigned id);
+
   private:
     static const unsigned datasize = 2;
     // Size of program_buffer in 32-bit words, as exposed to the rest of the
@@ -119,9 +124,10 @@ class debug_module_t : public abstract_device_t
     uint8_t debug_abstract[debug_abstract_size * 4];
     uint8_t *program_buffer;
     uint8_t dmdata[datasize * 4];
-    
+
     bool halted[1024];
     bool resumeack[1024];
+    bool havereset[1024];
     uint8_t debug_rom_flags[1024];
 
     void write32(uint8_t *rom, unsigned int index, uint32_t value);
diff --git a/riscv/processor.cc b/riscv/processor.cc
index 35adc10..5a57c28 100644
--- a/riscv/processor.cc
+++ b/riscv/processor.cc
@@ -154,6 +154,8 @@ void processor_t::reset()
 
   if (ext)
     ext->reset(); // reset the extension
+
+  sim->proc_reset(id);
 }
 
 // Count number of contiguous 0 bits starting from the LSB.
diff --git a/riscv/sim.cc b/riscv/sim.cc
index 81c5f6f..04fbe3c 100644
--- a/riscv/sim.cc
+++ b/riscv/sim.cc
@@ -364,3 +364,8 @@ void sim_t::write_chunk(addr_t taddr, size_t len, const void* src)
   memcpy(&data, src, sizeof data);
   debug_mmu->store_uint64(taddr, data);
 }
+
+void sim_t::proc_reset(unsigned id)
+{
+  debug_module.proc_reset(id);
+}
diff --git a/riscv/sim.h b/riscv/sim.h
index 9a0a10b..257de5b 100644
--- a/riscv/sim.h
+++ b/riscv/sim.h
@@ -24,6 +24,8 @@ public:
   // used for MMIO addresses
   virtual bool mmio_load(reg_t addr, size_t len, uint8_t* bytes) = 0;
   virtual bool mmio_store(reg_t addr, size_t len, const uint8_t* bytes) = 0;
+  // Callback for processors to let the simulation know they were reset.
+  virtual void proc_reset(unsigned id) = 0;
 };
 
 // this class encapsulates the processors and memory in a RISC-V machine.
@@ -49,6 +51,9 @@ public:
   processor_t* get_core(size_t i) { return procs.at(i); }
   unsigned nprocs() const { return procs.size(); }
 
+  // Callback for processors to let the simulation know they were reset.
+  void proc_reset(unsigned id);
+
 private:
   std::vector<std::pair<reg_t, mem_t*>> mems;
   mmu_t* debug_mmu;  // debug port into main memory
-- 
2.30.2