Merge pull request #433 from gsomlo/gls-rocket-spisdcard

Support SPI-mode SDCard booting on Litex+Rocket (64bit) configuration

litex/boards/platforms/nexys4ddr.py

@@ -57,6 +57,15 @@ _io = [
         IOStandard("LVCMOS33"),
     ),
 
+    ("spisdcard", 0,
+        Subsignal("rst",  Pins("E2")),
+        Subsignal("clk",  Pins("B1")),
+        Subsignal("mosi", Pins("C1"), Misc("PULLUP True")),
+        Subsignal("cs_n", Pins("D2"), Misc("PULLUP True")),
+        Subsignal("miso", Pins("C2"), Misc("PULLUP True")),
+        IOStandard("LVCMOS33"), Misc("SLEW=FAST")
+    ),
+
     ("sdcard", 0,
         Subsignal("rst", Pins("E2"), Misc("PULLUP True")),
         Subsignal("data", Pins("C2 E1 F1 D2"), Misc("PULLUP True")),

litex/boards/targets/nexys4ddr.py

@@ -25,6 +25,8 @@ from litesdcard.core import SDCore
 from litesdcard.bist import BISTBlockGenerator, BISTBlockChecker
 from litex.soc.cores.timer import Timer
 
+from litex.soc.cores.spi import SPIMaster
+
 # CRG ----------------------------------------------------------------------------------------------
 
 class _CRG(Module):
@@ -85,8 +87,16 @@ class BaseSoC(SoCCore):
             self.add_csr("ethphy")
             self.add_ethernet(phy=self.ethphy)
 
+    def add_spisdcard(self):
+        spisdcard_pads = self.platform.request("spisdcard")
+        if hasattr(spisdcard_pads, "rst"):
+            self.comb += spisdcard_pads.rst.eq(0)
+        self.submodules.spisdcard = SPIMaster(spisdcard_pads, 8, self.sys_clk_freq, 400e3)
+        self.add_csr("spisdcard")
+
     def add_sdcard(self):
         sdcard_pads = self.platform.request("sdcard")
+        if hasattr(sdcard_pads, "rst"):
             self.comb += sdcard_pads.rst.eq(0)
         self.submodules.sdclk = SDClockerS7(sys_clk_freq=self.sys_clk_freq)
         self.submodules.sdphy = SDPHY(sdcard_pads, self.platform.device)
@@ -122,6 +132,8 @@ def main():
                         help="system clock frequency (default=75MHz)")
     parser.add_argument("--with-ethernet", action="store_true",
                         help="enable Ethernet support")
+    parser.add_argument("--with-spi-sdcard", action="store_true",
+                        help="enable SPI-mode SDCard support")
     parser.add_argument("--with-sdcard", action="store_true",
                         help="enable SDCard support")
     args = parser.parse_args()
@@ -129,7 +141,11 @@ def main():
     soc = BaseSoC(sys_clk_freq=int(float(args.sys_clk_freq)),
         with_ethernet=args.with_ethernet,
         **soc_sdram_argdict(args))
+    if args.with_spi_sdcard:
+        soc.add_spisdcard()
     if args.with_sdcard:
+        if args.with_spi_sdcard:
+            raise ValueError("'--with-spi-sdcard' and '--with-sdcard' are mutually exclusive!")
         soc.add_sdcard()
     builder = Builder(soc, **builder_argdict(args))
     builder.build()

litex/soc/software/bios/boot.c

@@ -505,11 +505,19 @@ void spisdcardboot(void)
 		return;
 	}
 
+#if defined(CONFIG_CPU_TYPE_VEXRISCV) && defined(CONFIG_CPU_VARIANT_LINUX)
 	if(spi_sdcard_readFile("IMAGE","",MAIN_RAM_BASE+KERNEL_IMAGE_RAM_OFFSET)==0) return;
 	if(spi_sdcard_readFile("ROOTFS~1","CPI",MAIN_RAM_BASE+ROOTFS_IMAGE_RAM_OFFSET)==0) return;
 	if(spi_sdcard_readFile("RV32","DTB",MAIN_RAM_BASE+DEVICE_TREE_IMAGE_RAM_OFFSET)==0) return;
 	if(spi_sdcard_readFile("EMULATOR","BIN",EMULATOR_RAM_BASE)==0) return;
 
 	boot(0,0,0,EMULATOR_RAM_BASE + EMULATOR_IMAGE_RAM_OFFSET);
+#else
+	if(spi_sdcard_readFile("BOOT","BIN",MAIN_RAM_BASE)==0) {
+		printf("SD Card SPI boot failed\n");
+		return;
+	}
+	boot(0, 0, 0, MAIN_RAM_BASE);
+#endif
 }
 #endif

litex/soc/software/libbase/spisdcard.c

@@ -228,7 +228,7 @@ unsigned char spi_sdcard_goidle(void)
         r=spi_read_byte();
 
     // CMD16 - Set SD CARD block size to 512 - Sector Size for the SD CARD
-    // Command Sequence is DUMMY=0xff (512 as unsigned long = 0x00000200) 0x00 0x00 0x02 0x00 CRC=0xff
+    // Command Sequence is DUMMY=0xff (512 as unsigned int = 0x00000200) 0x00 0x00 0x02 0x00 CRC=0xff
     // Expected R1 response is 0x00 indicating SD CARD is READY
     spi_write_byte( 0xff ); spi_write_byte( 0x50 ); spi_write_byte( 0x00 ); spi_write_byte( 0x00 ); spi_write_byte( 0x02 ); spi_write_byte( 0x00 ); spi_write_byte( 0xff );
     r=spi_read_rbyte();
@@ -294,8 +294,8 @@ typedef struct {
     unsigned char start_chs[3];
     unsigned char partition_type;
     unsigned char end_chs[3];
-    unsigned long start_sector;
-    unsigned long length_sectors;
+    unsigned int start_sector;
+    unsigned int length_sectors;
 } __attribute((packed)) PartitionTable;
 
 PartitionTable sdCardPartition;
@@ -314,13 +314,13 @@ typedef struct {
     unsigned short fat_size_sectors;
     unsigned short sectors_per_track;
     unsigned short number_of_heads;
-    unsigned long hidden_sectors;
-    unsigned long total_sectors_long;
+    unsigned int hidden_sectors;
+    unsigned int total_sectors_long;
 
     unsigned char drive_number;
     unsigned char current_head;
     unsigned char boot_signature;
-    unsigned long volume_id;
+    unsigned int volume_id;
     char volume_label[11];
     char fs_type[8];
     char boot_code[448];
@@ -339,7 +339,7 @@ typedef struct {
     unsigned short modify_time;
     unsigned short modify_date;
     unsigned short starting_cluster;
-    unsigned long file_size;
+    unsigned int file_size;
 } __attribute((packed)) Fat16Entry;
 
 Fat16Entry *sdCardFat16RootDir;
@@ -510,7 +510,7 @@ unsigned char spi_sdcard_readFile(char *filename, char *ext, unsigned long addre
 {
     int i, n, sector;
     unsigned short fileClusterStart;
-    unsigned long fileLength, bytesRemaining, clusterSectorStart;
+    unsigned int fileLength, bytesRemaining, clusterSectorStart;
     unsigned short nameMatch;
     printf("Reading File [%s.%s] into 0x%08x : ",filename, ext, address);