--- /dev/null
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2011 Aleph One Ltd.
+ * for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "ynorsim.h"
+
+
+
+#include <stdio.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <time.h>
+
+#define YNORSIM_FNAME "emfile-nor"
+
+/* 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 2
+
+#if 0
+/* 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)
+#else
+/* Simulate 8MB of flash in 256k byte blocks.
+ * This stuff is x32.
+ */
+
+#define YNORSIM_BLOCK_SIZE_U32 (256*1024/4)
+#define YNORSIM_DEV_SIZE_U32 (8*1024 * 1024/4)
+#endif
+
+static u32 word[YNORSIM_DEV_SIZE_U32];
+
+extern int random_seed;
+extern int simulate_power_failure;
+
+static void NorError(void)
+{
+ printf("Nor error\n");
+ while(1){}
+}
+
+static void ynorsim_save_image(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_restore_image(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_power_fail(void)
+{
+ ynorsim_save_image();
+ exit(1);
+}
+
+static int initialised = 0;
+static int remaining_ops;
+static int nops_so_far;
+
+int ops_multiplier = 500;
+
+static void ynorsim_maybe_power_fail(void)
+{
+
+ nops_so_far++;
+
+
+ remaining_ops--;
+ if(simulate_power_failure &&
+ remaining_ops < 1){
+ printf("Simulated power failure after %d operations\n",nops_so_far);
+ ynorsim_power_fail();
+ }
+}
+
+static void ynorsim_ready(void)
+{
+ if(initialised)
+ return;
+ srand(random_seed);
+ remaining_ops = 1000000000;
+ remaining_ops = (rand() % 10000) * ops_multiplier * YNORSIM_BIT_CHANGES;
+ ynorsim_restore_image();
+}
+
+void ynorsim_rd32(u32 *addr,u32 *buf, int nwords)
+{
+ while(nwords > 0){
+ *buf = *addr;
+ buf++;
+ addr++;
+ nwords--;
+ }
+}
+
+void ynorsim_wr_one_word32(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_maybe_power_fail();
+ }
+
+ }
+
+ *addr = tmp & val;
+ ynorsim_maybe_power_fail();
+}
+
+void ynorsim_wr32(u32 *addr, u32 *buf, int nwords)
+{
+ while(nwords >0){
+ ynorsim_wr_one_word32(addr,*buf);
+ addr++;
+ buf++;
+ nwords--;
+ }
+}
+
+void ynorsim_erase(u32 *addr)
+{
+ /* Todo... bit flipping */
+ memset(addr,0xFF,YNORSIM_BLOCK_SIZE_U32 * 4);
+}
+
+void ynorsim_initialise(void)
+{
+ ynorsim_ready();
+}
+
+void ynorsim_shutdown(void)
+{
+ ynorsim_save_image();
+ initialised=0;
+}
+
+u32 *ynorsim_get_base(void)
+{
+ return word;
+}