target & board: AT91SAM7A2 and Olimex SAM7-LA2

Initial Support for AT91SAM7A2 on Olimex SAM7-LA2 board.
The board seems not to be able to reset into halted mode, as srst is
connected to NRESET of the cpu (configured srst_pulls_trst).
JTAG RCLK is connected to CLK.
Tested with interface/ftdi/olimex-arm-usb-ocd-h.cfg.

Change-Id: I2bdd67e3683e45f1119c5850bad294aa107891d8
Signed-off-by: Arne Wichmann <arne.wichmann@gmail.com>
Reviewed-on: http://openocd.zylin.com/2318
Tested-by: jenkins
Reviewed-by: Paul Fertser <fercerpav@gmail.com>

tcl/board/olimex_sam7_la2.cfg

@@ -0,0 +1,76 @@
+source [find target/at91sam7a2.cfg]
+
+# delays needed to get stable reads of cpu state
+jtag_ntrst_delay 10
+adapter_nsrst_delay 200
+
+# board uses pullup and connects only srst
+reset_config srst_open_drain
+
+# srst is connected to NRESET of CPU and fully resets everything...
+reset_config srst_only srst_pulls_trst
+
+adapter_khz 1
+$_TARGETNAME configure -event reset-start {
+	adapter_khz 1
+}
+
+$_TARGETNAME configure -event reset-init {
+	# init script from http://www.mikrocontroller.net/topic/107462
+	# AT91SAM7A2
+	# AMC (advanced memory controller)
+
+	echo "setting up AMC"
+	# AMC_CS0 - FLASH 1MB (0x40000000-0x400FFFFF) + DM9000E (0x40100000)
+	mww 0xFFE00000 0x40003EBD
+
+	# AMC_CS1 - RAM low 2MB (0x40400000-0x405FFFFF)
+	mww 0xFFE00004 0x404030A9
+
+	# AMC_CS2 - RAM high 2MB (0x40800000-0x405FFFFF)
+	#mww 0xFFE00008 0x404030A9
+	# changed to  0x40_8_
+	mww 0xFFE00008 0x408030A9
+
+	# AMC_MCR
+	mww 0xFFE00024 0x00000004
+
+	# AMC_RCR force remap
+	mww 0xFFE00020 0x00000001
+
+	echo "set up AMC"
+	sleep 100
+
+	# the following base addresses from the original script did not correspond to those from datasheet
+	# changed bases from 0xFF000000 to 0xFFF00000
+
+	# disable watchdog, to prevent unwanted resets
+	mww 0xFFFA0068 0x00000000
+	echo "disabled watchdog"
+
+	sleep 50
+
+	# disable PLL
+	mww 0xFFFEC004 0x18070004
+
+	# PLL = 10 ==> Coreclock = 6Mhz*10/2 = 30 Mhz
+	mww 0xFFFEC010 0x762D800A
+
+	# enable PLL
+	mww 0xFFFEC000 0x23050004
+	echo "set up pll"
+
+	sleep 100
+	adapter_khz 5000
+}
+
+$_TARGETNAME arm7_9 dcc_downloads enable
+$_TARGETNAME arm7_9 fast_memory_access enable
+
+# remap:  ram at 0, flash at 0x40000000, like reset-init above does
+$_TARGETNAME configure -work-area-phys 0x00000000 -work-area-size 0x4000 -work-area-backup 1
+flash bank onboard.flash cfi 0x40000000 0x00100000 2 2 at91sam7a2.cpu
+
+# boot: ram at 0x300000, flash at 0x0, useful if board is in funny configuration
+#$_TARGETNAME configure -work-area-phys 0x00300000 -work-area-size 0x4000 -work-area-backup 1
+#flash bank onboard1.flash cfi 0x00000000 0x00100000 2 2 at91sam7a2.cpu

tcl/target/at91sam7a2.cfg

@@ -0,0 +1,23 @@
+
+if { [info exists CHIPNAME] } {
+   set _CHIPNAME $CHIPNAME
+} else {
+   set _CHIPNAME at91sam7a2
+}
+
+if { [info exists ENDIAN] } {
+   set _ENDIAN $ENDIAN
+} else {
+   set _ENDIAN little
+}
+
+if { [info exists CPUTAPID] } {
+   set _CPUTAPID $CPUTAPID
+} else {
+   set _CPUTAPID 0x1f0f0f0f
+}
+
+jtag newtap $_CHIPNAME cpu -irlen 4 -ircapture 0x1 -irmask 0xf -expected-id $_CPUTAPID
+set _TARGETNAME $_CHIPNAME.cpu
+
+target create $_TARGETNAME arm7tdmi -endian $_ENDIAN -chain-position $_TARGETNAME