ac14xx: rephrase network boot config for development

- remove the builtin 'rootpath' spec (according to U-Boot project
  policy) and require user provided environments to contain these
- rephrase the evaluation of the 'muster_nr' approach which allows to
  quickly switch among several network boot setups (make the setting
  transparent when empty, resulting in default DULG behaviour)
- reduce the ARP timeout for faster network boot

Signed-off-by: Gerhard Sittig <gsi@denx.de>

include/configs/ac14xx.h

@@ -505,15 +505,15 @@
 	"echo"
 
 #define CONFIG_EXTRA_ENV_SETTINGS_DEVEL					\
-	"muster_nr=00\0"						\
+	"muster_nr=-00\0"						\
 	"fromram=run ramargs addip addtty; "				\
-		"tftp ${fdt_addr_r} ac14xx/ac14xx.dtb-${muster_nr}; "	\
-		"tftp ${kernel_addr_r} ac14xx/uImage-${muster_nr}; "	\
-		"tftp ${ramdisk_addr_r} ac14xx/uFS-${muster_nr}; "	\
+		"tftp ${fdt_addr_r} ac14xx/ac14xx.dtb${muster_nr}; "	\
+		"tftp ${kernel_addr_r} ac14xx/uImage${muster_nr}; "	\
+		"tftp ${ramdisk_addr_r} ac14xx/uFS${muster_nr}; "	\
 		"bootm ${kernel_addr_r} ${ramdisk_addr_r} ${fdt_addr_r}\0" \
 	"fromnfs=run nfsargs addip addtty; "				\
-		"tftp ${fdt_addr_r} ac14xx/ac14xx.dtb-${muster_nr}; "	\
-		"tftp ${kernel_addr_r} ac14xx/uImage-${muster_nr}; "	\
+		"tftp ${fdt_addr_r} ac14xx/ac14xx.dtb${muster_nr}; "	\
+		"tftp ${kernel_addr_r} ac14xx/uImage${muster_nr}; "	\
 		"bootm ${kernel_addr_r} - ${fdt_addr_r}\0"		\
 	"fromflash=run nfsargs addip addtty; "				\
 		"bootm fc020000 - fc000000\0"				\
@@ -541,12 +541,11 @@
 	"u-boot=ac14xx/u-boot.bin\0"					\
 	"bootfile=ac14xx/uImage\0"					\
 	"fdtfile=ac14xx/ac14xx.dtb\0"					\
-	"rootpath=/opt/eldk/ppc_6xx\n"					\
 	"netdev=eth0\0"							\
 	"consdev=ttyPSC0\0"						\
 	"hostname=ac14xx\0"						\
 	"nfsargs=setenv bootargs root=/dev/nfs rw "			\
-		"nfsroot=${serverip}:${rootpath}-${muster_nr}\0"	\
+		"nfsroot=${serverip}:${rootpath}${muster_nr}\0"	\
 	"ramargs=setenv bootargs root=/dev/ram rw\0"			\
 	"addip=setenv bootargs ${bootargs} "				\
 		"ip=${ipaddr}:${serverip}:${gatewayip}:${netmask}"	\
@@ -576,6 +575,8 @@
 
 #define CONFIG_BOOTCOMMAND	"run production"
 
+#define CONFIG_ARP_TIMEOUT	200UL
+
 #define CONFIG_FIT		1
 #define CONFIG_OF_LIBFDT	1
 #define CONFIG_OF_BOARD_SETUP	1