Add option to display customised memory information

Some boards want to report more than just memory size. For example, it
might be useful to display the memory type (DDR2, DDR3) or manufacturer.

Add a weak function to support this requirement, accessed through a new
'meminfo' command.

Any example of the DRAM: output is below, just for illustration:

SMDK5250 # meminfo
DRAM:  2 GiB Elpida DDR3 @ 800MHz

Signed-off-by: Simon Glass <sjg@chromium.org>

README

@@ -849,6 +849,7 @@ The following options need to be configured:
 		CONFIG_CMD_LOADS	  loads
 		CONFIG_CMD_MD5SUM	  print md5 message digest
 					  (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
+		CONFIG_CMD_MEMINFO	* Display detailed memory information
 		CONFIG_CMD_MEMORY	  md, mm, nm, mw, cp, cmp, crc, base,
 					  loop, loopw, mtest
 		CONFIG_CMD_MISC		  Misc functions like sleep etc

common/cmd_mem.c

@@ -33,6 +33,9 @@
 #include <dataflash.h>
 #endif
 #include <watchdog.h>
+#include <linux/compiler.h>
+
+DECLARE_GLOBAL_DATA_PTR;
 
 static int mod_mem(cmd_tbl_t *, int, int, int, char * const []);
 
@@ -1203,6 +1206,22 @@ U_BOOT_CMD(
 
 #endif
 
+#ifdef CONFIG_CMD_MEMINFO
+__weak void board_show_dram(ulong size)
+{
+	puts("DRAM:  ");
+	print_size(size, "\n");
+}
+
+static int do_mem_info(cmd_tbl_t *cmdtp, int flag, int argc,
+		       char * const argv[])
+{
+	board_show_dram(gd->ram_size);
+
+	return 0;
+}
+#endif
+
 U_BOOT_CMD(
 	base,	2,	1,	do_mem_base,
 	"print or set address offset",
@@ -1243,3 +1262,11 @@ U_BOOT_CMD(
 	"[.b, .w, .l] address value delay(ms)"
 );
 #endif /* CONFIG_MX_CYCLIC */
+
+#ifdef CONFIG_CMD_MEMINFO
+U_BOOT_CMD(
+	meminfo,	3,	1,	do_mem_info,
+	"display memory information",
+	""
+);
+#endif

include/common.h

@@ -311,6 +311,15 @@ int mac_read_from_eeprom(void);
 extern u8 _binary_dt_dtb_start[];	/* embedded device tree blob */
 int set_cpu_clk_info(void);
 
+/**
+ * Show the DRAM size in a board-specific way
+ *
+ * This is used by boards to display DRAM information in their own way.
+ *
+ * @param size	Size of DRAM (which should be displayed along with other info)
+ */
+void board_show_dram(ulong size);
+
 /* common/flash.c */
 void flash_perror (int);
 

include/config_cmd_all.h

@@ -56,6 +56,7 @@
 #define CONFIG_CMD_LICENSE	/* console license display	*/
 #define CONFIG_CMD_LOADB	/* loadb			*/
 #define CONFIG_CMD_LOADS	/* loads			*/
+#define CONFIG_CMD_MEMINFO	/* meminfo			*/
 #define CONFIG_CMD_MEMORY	/* md mm nm mw cp cmp crc base loop mtest */
 #define CONFIG_CMD_MFSL		/* FSL support for Microblaze	*/
 #define CONFIG_CMD_MII		/* MII support			*/