diff --git a/fpga/zsbl/boot.c b/fpga/zsbl/boot.c
index 16f7c0430..96bde4205 100644
--- a/fpga/zsbl/boot.c
+++ b/fpga/zsbl/boot.c
@@ -52,10 +52,40 @@ int disk_read(BYTE * buf, LBA_t sector, UINT count) {
     return -1;
   }
 
-  // Begin reading 
+  // Begin reading blocks
   for (i = 0; i < count; i++) {
+    uint16_t crc, crc_exp;
+    
+    // Read the data token
+    r = spi_readbyte();
+    if (r != SD_DATA_TOKEN) {
+      print_uart("Didn't receive data token first thing. Shoot: ");
+      print_byte(r & 0xff);
+      return -1;
+    }
+
+    // Read block into memory.
+    for (int j = 0; j < 8; j++) {
+      *buf = sd_read64(&crc);
+      buf = buf + 64;
+    }
+
+    // Read CRC16 and check
+    crc_exp = ((uint16_t)spi_txrx(0xff) << 8);
+    crc_exp |= spi_txrx(0xff);
+
+    if (crc != crc_exp) {
+      print_uart("Stinking CRC16 didn't match on block ");
+      print_int(i);
+      print_uart("\r\n");
+      return -1;
+    }
     
   }
+
+  sd_cmd(SD_CMD_STOP_TRANSMISSION, 0, 0x01);
+  spi_txrx(0xff);
+  return 0;
 }
 
 // copyFlash: --------------------------------------------------------
diff --git a/fpga/zsbl/sd.h b/fpga/zsbl/sd.h
index a70d203e7..37e4a2c94 100644
--- a/fpga/zsbl/sd.h
+++ b/fpga/zsbl/sd.h
@@ -15,4 +15,5 @@
 uint8_t crc7(uint8_t prev, uint8_t in);
 uint16_t crc16(uint16_t crc, uint8_t data);
 uint64_t sd_cmd(uint8_t cmd, uint32_t arg, uint8_t crc);
+uint64_t sd_read64(uint16_t * crc);
 void init_sd();
diff --git a/fpga/zsbl/spi.c b/fpga/zsbl/spi.c
index 687a98ceb..76985a350 100644
--- a/fpga/zsbl/spi.c
+++ b/fpga/zsbl/spi.c
@@ -58,6 +58,12 @@ inline void waitrx() {
   while(read_reg(SPI_IP) & 2)) {}
 }
 
+uint8_t spi_txrx(uint8_t byte) {
+  spi_sendbyte(0xFF);
+  waittx();
+  return spi_readbyte();
+}
+
 uint64_t spi_read64() {
   uint64_t r;
   uint8_t rbyte;