diff --git a/arch/sandbox/include/asm/test.h b/arch/sandbox/include/asm/test.h
index cd2b9e3155..73cb451e7f 100644
--- a/arch/sandbox/include/asm/test.h
+++ b/arch/sandbox/include/asm/test.h
@@ -72,6 +72,10 @@ void sandbox_i2c_eeprom_set_test_mode(struct udevice *dev,
 
 void sandbox_i2c_eeprom_set_offset_len(struct udevice *dev, int offset_len);
 
+uint sanbox_i2c_eeprom_get_prev_addr(struct udevice *dev);
+
+uint sanbox_i2c_eeprom_get_prev_offset(struct udevice *dev);
+
 /**
  * sandbox_i2c_rtc_set_offset() - set the time offset from system/base time
  *
diff --git a/drivers/misc/i2c_eeprom_emul.c b/drivers/misc/i2c_eeprom_emul.c
index 29ed45923f..284267f2ea 100644
--- a/drivers/misc/i2c_eeprom_emul.c
+++ b/drivers/misc/i2c_eeprom_emul.c
@@ -27,6 +27,8 @@ struct sandbox_i2c_flash_plat_data {
 
 struct sandbox_i2c_flash {
 	uint8_t *data;
+	uint prev_addr;		/* slave address of previous access */
+	uint prev_offset;	/* offset of previous access */
 };
 
 void sandbox_i2c_eeprom_set_test_mode(struct udevice *dev,
@@ -44,6 +46,20 @@ void sandbox_i2c_eeprom_set_offset_len(struct udevice *dev, int offset_len)
 	plat->offset_len = offset_len;
 }
 
+uint sanbox_i2c_eeprom_get_prev_addr(struct udevice *dev)
+{
+	struct sandbox_i2c_flash *priv = dev_get_priv(dev);
+
+	return priv->prev_addr;
+}
+
+uint sanbox_i2c_eeprom_get_prev_offset(struct udevice *dev)
+{
+	struct sandbox_i2c_flash *priv = dev_get_priv(dev);
+
+	return priv->prev_offset;
+}
+
 static int sandbox_i2c_eeprom_xfer(struct udevice *emul, struct i2c_msg *msg,
 				  int nmsgs)
 {
@@ -52,6 +68,10 @@ static int sandbox_i2c_eeprom_xfer(struct udevice *emul, struct i2c_msg *msg,
 
 	debug("\n%s\n", __func__);
 	debug_buffer(0, priv->data, 1, 16, 0);
+
+	/* store addr for testing visibity */
+	priv->prev_addr = msg->addr;
+
 	for (; nmsgs > 0; nmsgs--, msg++) {
 		struct sandbox_i2c_flash_plat_data *plat =
 				dev_get_platdata(emul);
@@ -60,11 +80,6 @@ static int sandbox_i2c_eeprom_xfer(struct udevice *emul, struct i2c_msg *msg,
 
 		if (!plat->size)
 			return -ENODEV;
-		if (msg->addr + msg->len > plat->size) {
-			debug("%s: Address %x, len %x is outside range 0..%x\n",
-			      __func__, msg->addr, msg->len, plat->size);
-			return -EINVAL;
-		}
 		len = msg->len;
 		debug("   %s: msg->len=%d",
 		      msg->flags & I2C_M_RD ? "read" : "write",
@@ -73,7 +88,16 @@ static int sandbox_i2c_eeprom_xfer(struct udevice *emul, struct i2c_msg *msg,
 			if (plat->test_mode == SIE_TEST_MODE_SINGLE_BYTE)
 				len = 1;
 			debug(", offset %x, len %x: ", offset, len);
-			memcpy(msg->buf, priv->data + offset, len);
+			if (offset + len > plat->size) {
+				int overflow = offset + len - plat->size;
+				int initial = len - overflow;
+
+				memcpy(msg->buf, priv->data + offset, initial);
+				memcpy(msg->buf + initial, priv->data,
+				       overflow);
+			} else {
+				memcpy(msg->buf, priv->data + offset, len);
+			}
 			memset(msg->buf + len, '\xff', msg->len - len);
 			debug_buffer(0, msg->buf, 1, msg->len, 0);
 		} else if (len >= plat->offset_len) {
@@ -87,15 +111,24 @@ static int sandbox_i2c_eeprom_xfer(struct udevice *emul, struct i2c_msg *msg,
 			if (plat->test_mode == SIE_TEST_MODE_SINGLE_BYTE)
 				len = min(len, 1);
 
-			/* For testing, map offsets into our limited buffer */
-			for (i = 24; i > 0; i -= 8) {
-				if (offset > (1 << i)) {
-					offset = (offset >> i) |
-						(offset & ((1 << i) - 1));
-					offset += i;
-				}
+			/* store offset for testing visibility */
+			priv->prev_offset = offset;
+
+			/* For testing, map offsets into our limited buffer.
+			 * offset wraps every 256 bytes
+			 */
+			offset &= 0xff;
+			debug("mapped offset to %x\n", offset);
+
+			if (offset + len > plat->size) {
+				int overflow = offset + len - plat->size;
+				int initial = len - overflow;
+
+				memcpy(priv->data + offset, ptr, initial);
+				memcpy(priv->data, ptr + initial, overflow);
+			} else {
+				memcpy(priv->data + offset, ptr, len);
 			}
-			memcpy(priv->data + offset, ptr, len);
 		}
 	}
 	debug_buffer(0, priv->data, 1, 16, 0);
diff --git a/test/dm/i2c.c b/test/dm/i2c.c
index cbbd4aa29a..bf5597b7a6 100644
--- a/test/dm/i2c.c
+++ b/test/dm/i2c.c
@@ -15,6 +15,7 @@
 #include <dm/test.h>
 #include <dm/uclass-internal.h>
 #include <dm/util.h>
+#include <hexdump.h>
 #include <test/ut.h>
 
 static const int busnum;
@@ -185,35 +186,54 @@ static int dm_test_i2c_offset(struct unit_test_state *uts)
 	ut_assertok(i2c_set_chip_offset_len(dev, 0));
 	ut_assertok(dm_i2c_write(dev, 10 /* ignored */, (uint8_t *)"AB", 2));
 	ut_assertok(dm_i2c_read(dev, 0, buf, 5));
-	ut_assertok(memcmp(buf, "AB\0\0\0\0", sizeof(buf)));
+	ut_asserteq_mem("AB\0\0\0\0", buf, sizeof(buf));
+	ut_asserteq(0, sanbox_i2c_eeprom_get_prev_offset(eeprom));
 
 	/* Offset length 1 */
 	sandbox_i2c_eeprom_set_offset_len(eeprom, 1);
 	ut_assertok(i2c_set_chip_offset_len(dev, 1));
 	ut_assertok(dm_i2c_write(dev, 2, (uint8_t *)"AB", 2));
+	ut_asserteq(2, sanbox_i2c_eeprom_get_prev_offset(eeprom));
 	ut_assertok(dm_i2c_read(dev, 0, buf, 5));
-	ut_assertok(memcmp(buf, "ABAB\0", sizeof(buf)));
+	ut_asserteq_mem("ABAB\0", buf, sizeof(buf));
+	ut_asserteq(0, sanbox_i2c_eeprom_get_prev_offset(eeprom));
 
-	/* Offset length 2 */
+	/* Offset length 2 boundary - check model wrapping */
 	sandbox_i2c_eeprom_set_offset_len(eeprom, 2);
 	ut_assertok(i2c_set_chip_offset_len(dev, 2));
-	ut_assertok(dm_i2c_write(dev, 0x210, (uint8_t *)"AB", 2));
-	ut_assertok(dm_i2c_read(dev, 0x210, buf, 5));
-	ut_assertok(memcmp(buf, "AB\0\0\0", sizeof(buf)));
+	ut_assertok(dm_i2c_write(dev, 0xFF, (uint8_t *)"A", 1));
+	ut_asserteq(0xFF, sanbox_i2c_eeprom_get_prev_offset(eeprom));
+	ut_assertok(dm_i2c_write(dev, 0x100, (uint8_t *)"B", 1));
+	ut_asserteq(0x100, sanbox_i2c_eeprom_get_prev_offset(eeprom));
+	ut_assertok(dm_i2c_write(dev, 0x101, (uint8_t *)"C", 1));
+	ut_asserteq(0x101, sanbox_i2c_eeprom_get_prev_offset(eeprom));
+	ut_assertok(dm_i2c_read(dev, 0xFF, buf, 5));
+	ut_asserteq_mem("ABCAB", buf, sizeof(buf));
+	ut_asserteq(0xFF, sanbox_i2c_eeprom_get_prev_offset(eeprom));
 
-	/* Offset length 3 */
+	/* Offset length 2 */
 	sandbox_i2c_eeprom_set_offset_len(eeprom, 2);
 	ut_assertok(i2c_set_chip_offset_len(dev, 2));
-	ut_assertok(dm_i2c_write(dev, 0x410, (uint8_t *)"AB", 2));
-	ut_assertok(dm_i2c_read(dev, 0x410, buf, 5));
-	ut_assertok(memcmp(buf, "AB\0\0\0", sizeof(buf)));
+	ut_assertok(dm_i2c_write(dev, 0x2020, (uint8_t *)"AB", 2));
+	ut_assertok(dm_i2c_read(dev, 0x2020, buf, 5));
+	ut_asserteq_mem("AB\0\0\0", buf, sizeof(buf));
+	ut_asserteq(0x2020, sanbox_i2c_eeprom_get_prev_offset(eeprom));
+
+	/* Offset length 3 */
+	sandbox_i2c_eeprom_set_offset_len(eeprom, 3);
+	ut_assertok(i2c_set_chip_offset_len(dev, 3));
+	ut_assertok(dm_i2c_write(dev, 0x303030, (uint8_t *)"AB", 2));
+	ut_assertok(dm_i2c_read(dev, 0x303030, buf, 5));
+	ut_asserteq_mem("AB\0\0\0", buf, sizeof(buf));
+	ut_asserteq(0x303030, sanbox_i2c_eeprom_get_prev_offset(eeprom));
 
 	/* Offset length 4 */
-	sandbox_i2c_eeprom_set_offset_len(eeprom, 2);
-	ut_assertok(i2c_set_chip_offset_len(dev, 2));
-	ut_assertok(dm_i2c_write(dev, 0x420, (uint8_t *)"AB", 2));
-	ut_assertok(dm_i2c_read(dev, 0x420, buf, 5));
-	ut_assertok(memcmp(buf, "AB\0\0\0", sizeof(buf)));
+	sandbox_i2c_eeprom_set_offset_len(eeprom, 4);
+	ut_assertok(i2c_set_chip_offset_len(dev, 4));
+	ut_assertok(dm_i2c_write(dev, 0x40404040, (uint8_t *)"AB", 2));
+	ut_assertok(dm_i2c_read(dev, 0x40404040, buf, 5));
+	ut_asserteq_mem("AB\0\0\0", buf, sizeof(buf));
+	ut_asserteq(0x40404040, sanbox_i2c_eeprom_get_prev_offset(eeprom));
 
 	/* Restore defaults */
 	sandbox_i2c_eeprom_set_offset_len(eeprom, 1);
