Some fixes and add NOR integrity code

[yaffs2.git] / direct / ynorsim.c

diff --git a/direct/ynorsim.c b/direct/ynorsim.c
new file mode 100644 (file)
index 0000000..569e0de
--- /dev/null
+++ b/direct/ynorsim.c
@@ -0,0 +1,156 @@
+
+
+#include "ynorsim.h"
+
+
+
+#include <stdio.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <time.h>
+
+#define YNORSIM_FNAME "ynorsimdata"
+
+/* Set YNORSIM_BIT_CHANGES to a a value from 1..30 to 
+ *simulate bit flipping as the programming happens. 
+ * A low value results in faster simulation with less chance of encountering a partially programmed
+ * word. 
+ */
+   
+//#define YNORSIM_BIT_CHANGES 15
+#define YNORSIM_BIT_CHANGES 1
+
+/* Simulate 32MB of flash in 256k byte blocks.
+ * This stuff is x32.
+ */
+
+#define YNORSIM_BLOCK_SIZE_U32  (256*1024/4)
+#define YNORSIM_DEV_SIZE_U32   (32*1024 * 1024/4)
+
+static __u32 word[YNORSIM_DEV_SIZE_U32];
+
+
+static void NorError(void)
+{
+  printf("Nor error\n");
+  while(1){}
+}
+
+static void ynorsim_SaveImage(void)
+{
+  int h = open(YNORSIM_FNAME, O_RDWR | O_CREAT | O_TRUNC, S_IREAD | S_IWRITE);
+  write(h,word,sizeof(word));
+  close(h);
+}
+
+static void ynorsim_RestoreImage(void)
+{
+  int h = open(YNORSIM_FNAME, O_RDONLY, S_IREAD | S_IWRITE);
+  memset(word,0xFF,sizeof(word));
+  read(h,word,sizeof(word));
+  close(h);
+}
+
+
+static void ynorsim_PowerFail(void)
+{
+  ynorsim_SaveImage();
+  exit(1);
+}
+
+static int initialised = 0;
+static int remaining_ops;
+static int nops_so_far;
+
+static void ynorsim_MaybePowerFail(void)
+{
+
+   nops_so_far++;
+   
+   
+   remaining_ops--;
+   if(remaining_ops < 1){
+       printf("Simulated power failure after %d operations\n",nops_so_far);
+       ynorsim_PowerFail();
+  }
+}
+
+static void ynorsim_Ready(void)
+{
+  if(initialised) 
+    return;
+  srand(time(NULL));
+  remaining_ops = 1000000000;
+  remaining_ops = (rand() % 10000) * 10000;
+  ynorsim_RestoreImage();
+}
+
+void ynorsim_Read32(__u32 *addr,__u32 *buf, int nwords)
+{ 
+   while(nwords > 0){
+     *buf = *addr;
+     buf++;
+     addr++;
+     nwords--;
+   }
+}
+
+void ynorsim_WriteOneWord32(__u32 *addr,__u32 val)
+{
+  __u32 tmp;
+  __u32 m;
+  int i;
+
+  tmp = *addr;
+  if(val & ~tmp){
+    // Fail due to trying to change a zero into a 1
+    printf("attempt to set a zero to one (%x)->(%x)\n",tmp,val);
+    NorError();
+  }
+  
+  for(i = 0; i < YNORSIM_BIT_CHANGES; i++){
+    m = 1 << (rand() & 31);
+    if(!(m & val)){
+      tmp &= ~m;
+      *addr = tmp;
+      ynorsim_MaybePowerFail();
+    }
+       
+  }
+  
+  *addr = tmp & val;
+  ynorsim_MaybePowerFail();
+}
+
+void ynorsim_Write32(__u32 *addr, __u32 *buf, int nwords)
+{
+  while(nwords >0){
+    ynorsim_WriteOneWord32(addr,*buf);
+    addr++;
+    buf++;
+    nwords--;
+  }
+}
+
+void ynorsim_EraseBlock(__u32 *addr)
+{
+  /* Todo... bit flipping */
+  memset(addr,0xFF,YNORSIM_BLOCK_SIZE_U32 * 4);
+}
+
+void ynorsim_Initialise(void)
+{
+  ynorsim_Ready();
+}
+
+void ynorsim_Shutdown(void)
+{
+  ynorsim_SaveImage();
+  initialised=0;
+}
+
+__u32 *ynorsim_GetBase(void)
+{
+  return word;
+}