Add option to set start pc

[riscv-isa-sim.git] / riscv / sim.cc

diff --git a/riscv/sim.cc b/riscv/sim.cc
index 7a10c9b4d2c9a4705cf726c0bd638e242950f7b4..59c4f0ed19fab07e697c7981827b0daa38a2e11a 100644 (file)
--- a/riscv/sim.cc
+++ b/riscv/sim.cc
@@ -23,26 +23,17 @@ static void handle_signal(int sig)
   signal(sig, &handle_signal);
 }
 
-sim_t::sim_t(const char* isa, size_t nprocs, size_t mem_mb, bool halted,
+sim_t::sim_t(const char* isa, size_t nprocs, bool halted, reg_t start_pc,
+             std::vector<std::pair<reg_t, mem_t*>> mems,
              const std::vector<std::string>& args)
-  : htif_t(args), procs(std::max(nprocs, size_t(1))),
+  : htif_t(args), mems(mems), procs(std::max(nprocs, size_t(1))),
+    start_pc(start_pc),
     current_step(0), current_proc(0), debug(false), gdbserver(NULL)
 {
   signal(SIGINT, &handle_signal);
-  // allocate target machine's memory, shrinking it as necessary
-  // until the allocation succeeds
-  size_t memsz0 = (size_t)mem_mb << 20;
-  size_t quantum = 1L << 20;
-  if (memsz0 == 0)
-    memsz0 = (size_t)2048 << 20;
 
-  memsz = memsz0;
-  while ((mem = (char*)calloc(1, memsz)) == NULL)
-    memsz = (size_t)(memsz*0.9)/quantum*quantum;
-
-  if (memsz != memsz0)
-    fprintf(stderr, "warning: only got %zu bytes of target mem (wanted %zu)\n",
-            memsz, memsz0);
+  for (auto& x : mems)
+    bus.add_device(x.first, x.second);
 
   bus.add_device(DEBUG_START, &debug_module);
 
@@ -63,7 +54,6 @@ sim_t::~sim_t()
   for (size_t i = 0; i < procs.size(); i++)
     delete procs[i];
   delete debug_mmu;
-  free(mem);
 }
 
 void sim_thread_main(void* arg)
@@ -238,14 +228,23 @@ static std::string dts_compile(const std::string& dts)
 
 void sim_t::make_dtb()
 {
-  uint32_t reset_vec[] = {
-    0x297 + DRAM_BASE - DEFAULT_RSTVEC, // auipc t0, DRAM_BASE
-    0x597,                              // auipc a1, 0
-    0x58593,                            // addi a1, a1, 0
-    0xf1402573,                                // csrr a0,mhartid
-    0x00028067                          // jalr zero, t0, 0 (jump straight to DRAM_BASE)
+  const int reset_vec_size = 8;
+
+  reg_t pc_delta = start_pc - DEFAULT_RSTVEC;
+  reg_t pc_delta_hi = (pc_delta + 0x800U) & ~reg_t(0xfffU);
+  reg_t pc_delta_lo = pc_delta - pc_delta_hi;
+  if ((pc_delta_hi >> 31) != 0 && (pc_delta_hi >> 31) != reg_t(-1) >> 31) {
+    fprintf(stderr, "initial pc %" PRIx64 " out of range\n", pc_delta);
+    abort();
+  }
+
+  uint32_t reset_vec[reset_vec_size] = {
+    0x297 + uint32_t(pc_delta_hi),              // auipc t0, &pc
+    0x597,                                      // auipc a1, &dtb
+    0x58593 + ((reset_vec_size - 1) * 4 << 20), // addi a1, a1, &dtb
+    0xf1402573,                                 // csrr a0, mhartid
+    0x28067 + uint32_t(pc_delta_lo << 20)       // jalr zero, t0, &pc
   };
-  reset_vec[2] += (sizeof(reset_vec) - 4) << 20; // addi a1, a1, sizeof(reset_vec) - 4 = DTB start
 
   std::vector<char> rom((char*)reset_vec, (char*)reset_vec + sizeof(reset_vec));
 
@@ -278,15 +277,16 @@ void sim_t::make_dtb()
          "      };\n"
          "    };\n";
   }
-  reg_t membs = DRAM_BASE;
-  s << std::hex <<
-         "  };\n"
-         "  memory@" << DRAM_BASE << " {\n"
+  s <<   "  };\n";
+  for (auto& m : mems) {
+    s << std::hex <<
+         "  memory@" << m.first << " {\n"
          "    device_type = \"memory\";\n"
-         "    reg = <0x" << (membs >> 32) << " 0x" << (membs & (uint32_t)-1) <<
-                   " 0x" << (memsz >> 32) << " 0x" << (memsz & (uint32_t)-1) << ">;\n"
-         "  };\n"
-         "  soc {\n"
+         "    reg = <0x" << (m.first >> 32) << " 0x" << (m.first & (uint32_t)-1) <<
+                   " 0x" << (m.second->size() >> 32) << " 0x" << (m.second->size() & (uint32_t)-1) << ">;\n"
+         "  };\n";
+  }
+  s <<   "  soc {\n"
          "    #address-cells = <2>;\n"
          "    #size-cells = <2>;\n"
          "    compatible = \"ucbbar,spike-bare-soc\", \"simple-bus\";\n"
@@ -316,6 +316,13 @@ void sim_t::make_dtb()
   bus.add_device(DEFAULT_RSTVEC, boot_rom.get());
 }
 
+char* sim_t::addr_to_mem(reg_t addr) {
+  auto desc = bus.find_device(addr);
+  if (auto mem = dynamic_cast<mem_t*>(desc.device))
+    return mem->contents() + (addr - desc.base);
+  return NULL;
+}
+
 // htif
 
 void sim_t::idle()