ram: re-add the init_ram function for VCS support (#168)

src/test/csrc/common/ram.cpp

@@ -30,6 +30,10 @@ CoDRAMsim3 *dram = NULL;
 
 SimMemory *simMemory = nullptr;
 
+void init_ram(const char *image, uint64_t ram_size) {
+  simMemory = new MmapMemory(image, ram_size);
+}
+
 #ifdef TLB_UNITTEST
 // Note: addpageSv39 only supports pmem base 0x80000000
 void addpageSv39() {

src/test/csrc/common/ram.h

@@ -202,6 +202,8 @@ class LinearizedFootprintsMemory : public FootprintsMemory {
 };
 
 extern SimMemory *simMemory;
+// This is to initialize the common mmap RAM
+void init_ram(const char *image, uint64_t n_bytes);
 
 #ifdef WITH_DRAMSIM3
 

src/test/csrc/vcs/vcs_main.cpp

@@ -61,7 +61,7 @@ extern "C" void set_max_cycles(long mc) {
 extern "C" void simv_init() {
   common_init("simv");
 
-  init_ram(bin_file);
+  init_ram(bin_file, DEFAULT_EMU_RAM_SIZE);
   init_flash(flash_bin_file);
 
   difftest_init();

src/test/csrc/verilator/emu.cpp

@@ -364,7 +364,7 @@ Emulator::Emulator(int argc, const char *argv[]):
       simMemory = new MmapMemoryWithFootprints(args.image, ram_size, args.footprints_name);
     }
     else {
-      simMemory = new MmapMemory(args.image, ram_size);
+      init_ram(args.image, ram_size);
     }
   }