Merge pull request #279 from RISCVERS/increase-ram-size

support simulating larger ram by using mmap

src/test/csrc/emu.cpp

@@ -125,9 +125,8 @@ Emulator::Emulator(int argc, const char *argv[]):
 }
 
 Emulator::~Emulator() {
-#ifdef WITH_DRAMSIM3
-  dramsim3_finish();
-#endif
+  ram_finish();
+
 #ifdef VM_SAVABLE
   snapshot_slot[0].save();
   snapshot_slot[1].save();

src/test/csrc/ram.cpp

+#include <sys/mman.h>
+#include <zlib.h>
+
 #include "common.h"
 #include "ram.h"
 
-#include <zlib.h>
-
-#define RAMSIZE (256 * 1024 * 1024)
+#define RAMSIZE (256 * 1024 * 1024UL)
 
 #ifdef WITH_DRAMSIM3
 #include "cosimulation.h"
 CoDRAMsim3 *dram = NULL;
 #endif
 
-static uint64_t ram[RAMSIZE / sizeof(uint64_t)];
+static uint64_t *ram;
 static long img_size = 0;
 void* get_img_start() { return &ram[0]; }
 long get_img_size() { return img_size; }
 void* get_ram_start() { return &ram[0]; }
 long get_ram_size() { return RAMSIZE; }
 
+#ifdef TLB_UNITTEST
 void addpageSv39() {
 //three layers
 //addr range: 0x0000000080000000 - 0x0000000088000000 for 128MB from 2GB - 2GB128MB
@@ -99,6 +101,7 @@ void addpageSv39() {
   memcpy((char *)ram+(RAMSIZE-PAGESIZE*(PTENUM+PDENUM)), pde, PAGESIZE*PDENUM);
   memcpy((char *)ram+(RAMSIZE-PAGESIZE*PTENUM), pte, PAGESIZE*PTENUM);
 }
+#endif
 
 // Return whether the file is a gz file
 int isGzFile(const char *img) {
@@ -116,23 +119,28 @@ int readFromGz(void* ptr, const char *file_name) {
   }
 
   uint64_t curr_size = 0;
+  // read 16KB each time
   const uint32_t chunk_size = 16384;
-  long *temp_page = new long[chunk_size];
-  long *pmem_current = (long*)ptr;
+  if ((RAMSIZE % chunk_size) != 0) {
+    printf("RAMSIZE must be divisible by chunk_size\n");
+    assert(0);
+  }
+  uint64_t *temp_page = new uint64_t[chunk_size];
+  uint64_t *pmem_current = (uint64_t *)ptr;
 
   while (curr_size < RAMSIZE) {
     uint32_t bytes_read = gzread(compressed_mem, temp_page, chunk_size);
     if (bytes_read == 0) { break; }
-    assert(bytes_read % sizeof(long) == 0);
-    for (uint32_t x = 0; x < bytes_read / sizeof(long); x++) {
+    assert(bytes_read % sizeof(uint64_t) == 0);
+    for (uint32_t x = 0; x < bytes_read / sizeof(uint64_t); x++) {
       if (*(temp_page + x) != 0) {
-        pmem_current = (long*)((uint8_t*)ptr + curr_size + x * sizeof(long));
+        pmem_current = (uint64_t*)((uint8_t*)ptr + curr_size + x * sizeof(uint64_t));
         *pmem_current = *(temp_page + x);
       }
     }
     curr_size += bytes_read;
   }
-  printf("Read %lu bytes from gz stream in total", curr_size);
+  // printf("Read 0x%lx bytes from gz stream in total.\n", curr_size);
 
   delete [] temp_page;
 
@@ -148,19 +156,21 @@ void init_ram(const char *img) {
 
   printf("The image is %s\n", img);
 
+  // initialize memory using Linux mmap
+  printf("Using simulated %luMB RAM\n", RAMSIZE / (1024 * 1024));
+  ram = (uint64_t *)mmap(NULL, RAMSIZE, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0);
+  if (ram == (uint64_t *)MAP_FAILED) {
+    printf("Cound not mmap 0x%lx bytes\n", RAMSIZE);
+    assert(0);
+  }
+
   int ret;
   if (isGzFile(img)) {
-    printf("Read from gz file\n");
+    printf("Gzip file detected and loading image from extracted gz file\n");
     img_size = readFromGz(ram, img);
-    if (img_size > RAMSIZE) {
-      img_size = RAMSIZE;
-    }
-
     assert(img_size >= 0);
   }
   else {
-    printf("Read from bin file\n");
-
     FILE *fp = fopen(img, "rb");
     if (fp == NULL) {
       printf("Can not open '%s'\n", img);
@@ -180,9 +190,11 @@ void init_ram(const char *img) {
     fclose(fp); 
   }
 
+#ifdef TLB_UNITTEST
   //new add
   addpageSv39();
   //new end
+#endif
 
 #ifdef WITH_DRAMSIM3
   #if !defined(DRAMSIM3_CONFIG) || !defined(DRAMSIM3_OUTDIR)
@@ -194,6 +206,13 @@ void init_ram(const char *img) {
 
 }
 
+void ram_finish() {
+  munmap(ram, RAMSIZE);
+#ifdef WITH_DRAMSIM3
+  dramsim3_finish();
+#endif
+}
+
 extern "C" uint64_t ram_read_helper(uint8_t en, uint64_t rIdx) {
   if (en && rIdx >= RAMSIZE / sizeof(uint64_t)) {
     printf("ERROR: ram idx = 0x%lx out of bound!\n", rIdx);

src/test/csrc/ram.h

@@ -3,8 +3,8 @@
 
 #include "common.h"
 
-// #define WITH_DRAMSIM3
 void init_ram(const char *img);
+void ram_finish();
 
 #ifdef WITH_DRAMSIM3
 // 4*64 bits