RM 1286. Support 64MB SDRAM on STM32f7-SOM as stm32f7-som-64_config

	 and stm32f7-som-64-ext-bsb_config.

Makefile

@@ -3246,6 +3246,8 @@ stm-som-1a_config : unconfig
 		}
 	@$(MKCONFIG) -a stm-som arm arm_cortexm3 stm-som emcraft stm32
 
+stm32f7-som-64_config \
+stm32f7-som-64-ext-bsb_config \
 stm32f7-som_config \
 stm32f7-som-ext-bsb_config: unconfig
 	@if [ "$(findstring ext-bsb, $@)" ] ; then \
@@ -3254,6 +3256,11 @@ stm32f7-som-ext-bsb_config: unconfig
 		echo "#define CONFIG_SYS_BOARD_UCL_BSB" >>$(obj)include/config.h ; \
 		echo "...for UCL-BSB" ; \
 	fi;
+	@if [ "$(findstring 64, $@)" ] ; then \
+		echo "...for 64MB SDRAM variant" ; \
+		echo "#define CONFIG_SYS_RAM_SIZE (64 * 1024 * 1024)" >> \
+		$(obj)include/config.h ; \
+	fi;
 	@$(MKCONFIG) -a stm32f7-som arm arm_cortexm3 stm32f7-som emcraft stm32
 
 stm32f429-discovery_config : unconfig

board/emcraft/stm32f7-som/board.c

@@ -580,7 +580,12 @@ static inline u32 _ns2clk(u32 ns, u32 freq)
 #define SDRAM_MWID	1	/* 16 bit memory */
 
 #define SDRAM_NR	0x2	/* 13-bit row */
+#if (CONFIG_SYS_RAM_SIZE == (32 * 1024 * 1024))
 #define SDRAM_NC	0x1	/* 9-bit col */
+#endif
+#if (CONFIG_SYS_RAM_SIZE == (64 * 1024 * 1024))
+#define SDRAM_NC	0x2	/* 10-bit col */
+#endif
 
 #define SDRAM_TRRD	NS2CLK(12)
 #define SDRAM_TRCD	NS2CLK(18)

cpu/arm_cortexm3/stm32/soc.c

@@ -180,7 +180,7 @@ static void stm32f7_mpu_config(void)
 		0 <<  8 | 31 <<  1 | 1 <<  0);
 
 	/*
-	 * Configure 32MB SDRAM region as Normal memory with the appropriate
+	 * Configure 64MB SDRAM region as Normal memory with the appropriate
 	 * cacheability attributes
 	 */
 	cortex_m3_mpu_set_region(MPU_RGN_SDRAM_CA,
@@ -193,7 +193,7 @@ static void stm32f7_mpu_config(void)
 		/* Non-cacheable */
 		1 << 19 |  0 << 18 | 0 << 17 | 0 << 16 |
 #endif
-		0 <<  8 | 24 <<  1 | 1 <<  0);
+		0 <<  8 | 25 <<  1 | 1 <<  0);
 
 #if defined(CONFIG_STM32F7_DCACHE_ON) || defined(CONFIG_STM32F7_ICACHE_ON)
 	stm32f7_envm_mpu_cfg(0, 0);

include/configs/stm32f7-som.h

@@ -160,7 +160,9 @@
  * Configuration of the external SDRAM memory
  */
 #define CONFIG_NR_DRAM_BANKS		1
+#ifndef CONFIG_SYS_RAM_SIZE
 #define CONFIG_SYS_RAM_SIZE		(32 * 1024 * 1024)
+#endif
 #define CONFIG_SYS_RAM_FREQ_DIV	2
 #define CONFIG_SYS_RAM_BASE		0xC0000000