bios: DDR initialization skeleton

Sebastien Bourdeauducq · Sebastien Bourdeauducq · commit c38de34a211c · 2012-02-17T18:47:04.000+01:00
diff --git a/software/bios/Makefile b/software/bios/Makefile
@@ -1,7 +1,7 @@
 M2DIR=../..
 include $(M2DIR)/software/include.mak
 
-OBJECTS=crt0.o isr.o main.o
+OBJECTS=crt0.o isr.o ddrinit.o main.o
 
 all: bios.bin
 
diff --git a/software/bios/ddrinit.c b/software/bios/ddrinit.c
@@ -0,0 +1,63 @@
+/*
+ * Milkymist SoC (Software)
+ * Copyright (C) 2012 Sebastien Bourdeauducq
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 3 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdio.h>
+
+#include <hw/s6ddrphy.h>
+
+#include "ddrinit.h"
+
+static void init_sequence(void)
+{
+	printf("Sending initialization sequence...\n");
+	// TODO
+}
+
+static void calibrate_phy(void)
+{
+	int requests;
+	int addr;
+	
+	printf("Calibrating PHY...\n");
+	while(!(CSR_DDRPHY_STATUS & DDRPHY_STATUS_PHY_CAL_DONE)) {
+		requests = CSR_DDRPHY_REQUESTS;
+		addr = CSR_DDRPHY_REQADDR;
+		
+		if(requests & DDRPHY_REQUEST_READ) {
+			printf("R %d\n", addr);
+			// TODO
+		}
+		if(requests & DDRPHY_REQUEST_WRITE) {
+			printf("W %d\n", addr);
+			// TODO
+		}
+		
+		CSR_DDRPHY_REQUESTS = requests;
+	}
+}
+
+int ddrinit(void)
+{
+	printf("Initializing DDR SDRAM...\n");
+	
+	CSR_DDRPHY_STATUS = DDRPHY_STATUS_RESETN;
+	init_sequence();
+	CSR_DDRPHY_STATUS = DDRPHY_STATUS_RESETN|DDRPHY_STATUS_INIT_DONE;
+	calibrate_phy();
+	
+	return 1;
+}
diff --git a/software/bios/ddrinit.h b/software/bios/ddrinit.h
@@ -0,0 +1,23 @@
+/*
+ * Milkymist SoC (Software)
+ * Copyright (C) 2012 Sebastien Bourdeauducq
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 3 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __DDRINIT_H
+#define __DDRINIT_H
+
+int ddrinit(void);
+
+#endif /* __DDRINIT_H */
diff --git a/software/bios/main.c b/software/bios/main.c
@@ -27,6 +27,8 @@
 
 #include <hw/flash.h>
 
+#include "ddrinit.h"
+
 enum {
 	CSR_IE = 1, CSR_IM, CSR_IP, CSR_ICC, CSR_DCC, CSR_CC, CSR_CFG, CSR_EBA,
 	CSR_DC, CSR_DEBA, CSR_JTX, CSR_JRX, CSR_BP0, CSR_BP1, CSR_BP2, CSR_BP3,
@@ -440,11 +442,12 @@ int main(int i, char **c)
 	uart_init();
 	printf(banner);
 	crcbios();
-
+	print_mac();
+	ddrinit();
+	
 	if(rescue)
 		printf("I: Booting in rescue mode\n");
-
-	print_mac();
+	
 	while(1) {
 		putsnonl("\e[1mBIOS>\e[0m ");
 		readstr(buffer, 64);
