Add support for KARO TX25 board

This is an i.MX25 base board with only NAND
so it uses nand_spl to boot.

Signed-off-by: John Rigby <jcrigby@gmail.com>

Tune configuration, add support for (redundant) environment in NAND.
Signed-off-by: Wolfgang Denk <wd@denx.de>

Acked-by: Wolfgang Denk <wd@denx.de>
CC: Fred Fan <fanyefeng@gmail.com>
CC: Tom <Tom.Rix@windriver.com>
diff --git a/board/karo/tx25/lowlevel_init.S b/board/karo/tx25/lowlevel_init.S
new file mode 100644
index 0000000..823df10
--- /dev/null
+++ b/board/karo/tx25/lowlevel_init.S
@@ -0,0 +1,131 @@
+/*
+ * (C) Copyright 2009 DENX Software Engineering
+ * Author: John Rigby <jrigby@gmail.com>
+ *
+ * Based on U-Boot and RedBoot sources for several different i.mx
+ * platforms.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <asm/macro.h>
+
+.macro init_aips
+	write32	0x43f00000, 0x77777777
+	write32	0x43f00004, 0x77777777
+	write32	0x43f00000, 0x77777777
+	write32	0x53f00004, 0x77777777
+.endm
+
+.macro init_max
+	write32	0x43f04000, 0x43210
+	write32	0x43f04100, 0x43210
+	write32	0x43f04200, 0x43210
+	write32	0x43f04300, 0x43210
+	write32	0x43f04400, 0x43210
+
+	write32	0x43f04010, 0x10
+	write32	0x43f04110, 0x10
+	write32	0x43f04210, 0x10
+	write32	0x43f04310, 0x10
+	write32	0x43f04410, 0x10
+
+	write32	0x43f04800, 0x0
+	write32	0x43f04900, 0x0
+	write32	0x43f04a00, 0x0
+	write32	0x43f04b00, 0x0
+	write32	0x43f04c00, 0x0
+.endm
+
+.macro init_m3if
+	write32 0xb8003000, 0x1
+.endm
+
+.macro init_clocks
+	/*
+	 * clocks
+	 *
+	 * first enable CLKO debug output
+	 * 0x40000000 enables the debug CLKO signal
+	 * 0x05000000 sets CLKO divider to 6
+	 * 0x00600000 makes CLKO parent clk the USB clk
+	 */
+	write32	0x53f80064, 0x45600000
+	write32	0x53f80008, 0x20034000
+
+	/*
+	 * enable all implemented clocks in all three
+	 * clock control registers
+	 */
+	write32	0x53f8000c, 0x1fffffff
+	write32	0x53f80010, 0xffffffff
+	write32	0x53f80014, 0xfdfff
+.endm
+
+.macro init_ddrtype
+	/*
+	 * ddr_type is 3.3v SDRAM
+	 */
+	write32	0x43fac454, 0x800
+.endm
+
+/*
+ * sdram controller init
+ */
+.macro init_sdram_bank bankaddr, ctl, cfg
+	ldr	r0, =0xb8001000
+	ldr	r2, =\bankaddr
+	/*
+	 * reset SDRAM controller
+	 * then wait for initialization to complete
+	 */
+	ldr	r1, =(1 << 1)
+	str	r1, [r0, #0x10]
+1:	ldr	r3, [r0, #0x10]
+	tst	r3, #(1 << 31)
+	beq	1b
+
+	ldr	r1, =0x95728
+	str	r1, [r0, #\cfg]		/* config */
+
+	ldr	r1, =0x92116480		/* control | precharge */
+	str	r1, [r0, #\ctl]		/* write command to controller */
+	str	r1, [r2, #0x400]	/* command encoded in address */
+
+	ldr	r1, =0xa2116480		/* auto refresh */
+	str	r1, [r0, #\ctl]
+	ldrb	r3, [r2]		/* read dram twice to auto refresh */
+	ldrb	r3, [r2]
+
+	ldr	r1, =0xb2116480		/* control | load mode */
+	str	r1, [r0, #\ctl]		/* write command to controller */
+	strb	r1, [r2, #0x33]		/* command encoded in address */
+
+	ldr	r1, =0x82116480		/* control  | normal (0)*/
+	str	r1, [r0, #\ctl]		/* write command to controller */
+.endm
+
+.globl lowlevel_init
+lowlevel_init:
+	init_aips
+	init_max
+	init_m3if
+	init_clocks
+
+	init_sdram_bank 0x80000000, 0x0, 0x4
+
+	init_sdram_bank 0x90000000, 0x8, 0xc
+	mov	pc, lr