arm: mvebu: board/Synology: Unify legacy kernel support

Move the relevant bits from ds109.{c,h} into common/ and adjust the code
to fit both DS109 and DS414. Moreover:

* Introduce syno_board_id() which translates CONFIG_MACH_TYPE into the
  expected board ID tag value.

* Properly initialize isusbhost, mac and mtu fields from env variables.

* Set the right bootargs/bootcmd to correctly boot legacy kernel out of
  the (DS414) box. Getting the ramdisk location right is a bit tedious.

Cc: Walter Schweizer <swwa@users.sourceforge.net>
Signed-off-by: Phil Sutter <phil@nwl.cc>
Reviewed-by: Stefan Roese <sr@denx.de>

include/configs/ds109.h

@@ -44,7 +44,8 @@
 	"x_bootcmd_kernel=fatload usb 0 0x6400000 uImage\0" \
 	"x_bootargs=console=ttyS0,115200\0"	\
 	"x_bootargs_root=root=/dev/sda2 rootdelay=10\0" \
-	"ipaddr=192.168.1.5\0"
+	"ipaddr=192.168.1.5\0"		\
+	"usb0Mode=host\0"
 
 /*
  * Ethernet Driver configuration

include/configs/ds414.h

@@ -6,6 +6,9 @@
 #ifndef _CONFIG_SYNOLOGY_DS414_H
 #define _CONFIG_SYNOLOGY_DS414_H
 
+/* Vendor kernel expects this MACH_TYPE */
+#define CONFIG_MACH_TYPE	3036
+
 /*
  * High Level Configuration Options (easy to change)
  */
@@ -74,8 +77,18 @@
 #define CONFIG_DDR_32BIT
 
 /* Default Environment */
-#define CONFIG_BOOTCOMMAND	"sf read ${loadaddr} 0xd0000 0x700000; bootm"
 #define CONFIG_LOADADDR		0x80000
+#define CONFIG_BOOTCOMMAND					\
+	"sf probe; "						\
+	"sf read ${loadaddr} 0xd0000 0x2d0000; "		\
+	"sf read ${ramdisk_addr_r} 0x3a0000 0x430000; "		\
+	"bootm ${loadaddr} ${ramdisk_addr_r}"
+
+#define CONFIG_EXTRA_ENV_SETTINGS				\
+	"initrd_high=0xffffffff\0"				\
+	"ramdisk_addr_r=0x8000000\0"				\
+	"usb0Mode=host\0usb1Mode=host\0usb2Mode=device\0"	\
+	"ethmtu=1500\0eth1mtu=1500\0"
 
 /* increase autoneg timeout, my NIC sucks */
 #define PHY_ANEG_TIMEOUT	16000