at91rm9200ek: add configure target for RAM boot

This patch also removes now unnecessary config.mk in board directory and
make usage of new features in boards.cfg.

Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>

board/atmel/at91rm9200ek/config.mk

@@ -1,2 +0,0 @@
-# currently only NOR flash booting is supported
-CONFIG_SYS_TEXT_BASE = 0x10000000

boards.cfg

@@ -48,7 +48,8 @@ lpc2292sodimm                arm         arm720t     -                   -
 SMN42                        arm         arm720t     -                   siemens        lpc2292
 evb4510                      arm         arm720t     -                   -              s3c4510b
 a320evb                      arm         arm920t     -                   faraday        a320
-at91rm9200ek                 arm         arm920t     -                   atmel          at91
+at91rm9200ek                 arm         arm920t     at91rm9200ek        atmel          at91        at91rm9200ek
+at91rm9200ek_ram             arm         arm920t     at91rm9200ek        atmel          at91        at91rm9200ek:RAMBOOT
 eb_cpux9k2                   arm         arm920t     -                   BuS            at91
 cmc_pu2                      arm         arm920t     -                   -              at91rm9200
 csb637                       arm         arm920t     -                   -              at91rm9200

include/configs/at91rm9200ek.h

@@ -32,6 +32,20 @@
 
 #include <asm/sizes.h>
 
+/*
+ * set some initial configurations depending on configure target
+ *
+ * at91rm9200ek_config     -> boot from 0x0 in NOR Flash at CS0
+ * at91rm9200ek_ram_config -> continue booting from 0x20100000 in RAM; lowlevel
+ *                            initialisation was done by some preloader
+ */
+#ifdef CONFIG_RAMBOOT
+#define CONFIG_SKIP_LOWLEVEL_INIT
+#define CONFIG_SYS_TEXT_BASE 0x20100000
+#else
+#define CONFIG_SYS_TEXT_BASE 0x10000000
+#endif
+
 /*
  * AT91C_XTAL_CLOCK is the frequency of external xtal in hertz
  * AT91C_MAIN_CLOCK is the frequency of PLLA output