From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Fri, 21 Jan 2022 13:38:50 +0000 (+0000)
Subject: add snapshot-saving currently every 1000 cycles for test purposes
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=6f6e4c9d482a1281f93cd77327826908d5eea3b3;p=microwatt.git

add snapshot-saving currently every 1000 cycles for test purposes
---

diff --git a/verilator/microwatt-verilator.cpp b/verilator/microwatt-verilator.cpp
index 0dbbf29..0b6f6b6 100644
--- a/verilator/microwatt-verilator.cpp
+++ b/verilator/microwatt-verilator.cpp
@@ -70,36 +70,46 @@ static void ascii_dump(unsigned char *data, int len, FILE *dump)
 }
 
 // save/restore of verilator model to/from file.
-void save_model(const char* filenamep, Vmicrowatt* topp)
+void save_model(vluint64_t time, Vmicrowatt* topp)
 {
+    char fname[128];
+    sprintf(fname, "verilator.save.%ld", time);
     VerilatedSave os;
-    os.open(filenamep);
+    os.open(fname);
     os << main_time;  // user code must save the timestamp, etc
     os << *topp;
 }
 
-void restore_model(const char* filenamep, Vmicrowatt* topp)
+void restore_model(vluint64_t time, Vmicrowatt* topp)
 {
+    char fname[128];
+    sprintf(fname, "verilator.save.%ld", time);
     VerilatedRestore os;
-    os.open(filenamep);
+    os.open(fname);
     os >> main_time;
     os >> *topp;
 }
 
 //save bram memory out to a file. use for snapshots
-int memdump(time_t time, unsigned char *mem, size_t sz)
+int memdump(unsigned char *mem, size_t sz)
 {
-  int fd = open("bram.snapshot.%ld", time, O_RDWR | O_CREAT, (mode_t)0600);
-  lseek(fd, sz, SEEK_SET);
-  write(fd, "", 1);
-  void *map = mmap(NULL, sz, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
-  memcpy(map, mem, sz);
-  msync(map, sz, MS_SYNC);
-  munmap(map, sz);
-  close(fd);
-  return 0;
+    char fname[128];
+    sprintf(fname, "bram.snapshot.%ld", main_time);
+    int fd = open(fname, O_RDWR | O_CREAT, (mode_t)0600);
+    lseek(fd, sz, SEEK_SET);
+    write(fd, "", 1);
+    void *map = mmap(NULL, sz, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
+    memcpy(map, mem, sz);
+    msync(map, sz, MS_SYNC);
+    munmap(map, sz);
+    close(fd);
+    return 0;
 }
 
+// save-trigger offsets
+vluint64_t save_offset = 1000;
+vluint64_t save_countdown = save_offset;
+
 // write (masked by sel) to internal mem offset by bram_addr line
 static void mem_write(unsigned char *mem,
                       unsigned long bram_addr, unsigned long long bram_di,
@@ -242,6 +252,17 @@ int main(int argc, char **argv)
 
 	while(!Verilated::gotFinish()) {
 
+        // check if a snapshot of the model should be actioned,
+        // otherwise continue counting down
+        if (save_countdown == 0) {
+            fprintf(dump, "snapshot saving at %ld\n", main_time);
+            fflush(dump);
+            save_model(main_time, top);
+            save_countdown = save_offset; // loop for next snapshot
+        } else {
+            --save_countdown;
+        }
+
 		tick(top, traceme);
 
         // read/write the memory to/from the mmap'd file (if given)