mpc83xx: Add the MPC837xEMDS board readme

Add the README.mpc837xemds to /doc

Signed-off-by: Dave Liu <daveliu@freescale.com>

doc/README.mpc837xemds

+Freescale MPC837xEMDS Board
+-----------------------------------------
+1.	Board Switches and Jumpers
+1.0 	There are four Dual-In-Line Packages(DIP) Switches on MPC837xEMDS board
+	For some reason, the HW designers describe the switch settings
+	in terms of 0 and 1, and then map that to physical switches where
+	the label "On" refers to logic 0 and "Off" is logic 1.
+
+	Switch bits are numbered 1 through, like, 4 6 8 or 10, but the
+	bits may contribute to signals that are numbered based at 0,
+	and some of those signals may be high-bit-number-0 too.  Heed
+	well the names and labels and do not get confused.
+
+		"Off" == 1
+		"On"  == 0
+
+	SW4[8] is the bit labled 8 on Switch 4.
+	SW2[1:6] refers to bits labeled 1 through 6 in order on switch 2.
+	SW2[1:8]= 0000_0001 refers to bits labeled 1 through 7 is set as "On"
+		and bits labeled 8 is set as "Off".
+
+1.1	For the MPC837xEMDS Processor Board
+
+	First, make sure the board default setting is consistent with the
+	document shipped with your board. Then apply the following setting:
+	SW3[1-8]= 0011_0000  (BOOTSEQ, ROMLOC setting)
+	SW4[1-8]= 0000_0110  (core PLL setting)
+	SW5[1-8]= 1001_1000  (system PLL, boot up from low end of flash)
+	SW6[1-8]= 0000_1000  (HRCW is read from NOR FLASH)
+	SW7[1-8]= 0110_1101  (TSEC1/2 interface setting - RGMII)
+	J3 2-3, TSEC1 LVDD1 with 2.5V
+	J6 2-3, TSEC2 LVDD2 with 2.5V
+	J9 2-3, CLKIN from osc on board
+	J10 removed, CS0 connect to NOR flash; when mounted, CS0 connect to NAND
+	J11 removed, Hardware Reset Configuration Word load from FLASH(NOR or NAND)
+	    mounted, HRCW load from BCSR.
+
+	on board Oscillator: 66M
+
+2.	Memory Map
+
+2.1.	The memory map should look pretty much like this:
+
+	0x0000_0000	0x7fff_ffff	DDR			2G
+	0x8000_0000	0x8fff_ffff	PCI MEM prefetch	256M
+	0x9000_0000	0x9fff_ffff	PCI MEM non-prefetch	256M
+	0xc000_0000	0xdfff_ffff	Empty			512M
+	0xe000_0000	0xe00f_ffff	Int Mem Reg Space	1M
+	0xe010_0000	0xe02f_ffff	Empty			2M
+	0xe030_0000	0xe03f_ffff	PCI IO			1M
+	0xe040_0000	0xe05f_ffff	Empty			2M
+	0xe060_0000	0xe060_8000	NAND Flash		32K
+	0xf400_0000	0xf7ff_ffff	Empty			64M
+	0xf800_0000	0xf800_7fff	BCSR on CS1		32K
+	0xfe00_0000	0xffff_ffff	NOR Flash on CS0	32M
+
+3. Definitions
+
+3.1 Explanation of NEW definitions in:
+
+	include/configs/MPC837XEMDS.h
+
+    CONFIG_MPC83XX	    MPC83xx family for both MPC837x and MPC8360
+    CONFIG_MPC837X	    MPC837x specific
+    CONFIG_MPC837XEMDS	    MPC837XEMDS board specific
+
+4. Compilation
+
+	Assuming you're using BASH shell:
+
+		export CROSS_COMPILE=your-cross-compile-prefix
+		cd u-boot
+		make distclean
+		make MPC837XEMDS_config
+		make
+
+5. Downloading and Flashing Images
+
+5.0 Download over serial line using Kermit:
+
+	loadb
+	[Drop to kermit:
+	    ^\c
+	    send <u-boot-bin-image>
+	    c
+	]
+
+
+    Or via tftp:
+
+	tftp 40000 u-boot.bin
+
+5.1 Reflash U-boot Image using U-boot
+
+	tftp 40000 u-boot.bin
+	protect off fe000000 fe1fffff
+	erase fe000000 fe1fffff
+
+	cp.b 40000 fe000000 xxxx
+
+You have to supply the correct byte count with 'xxxx' from the TFTP result log.
+
+6. Notes
+	1) The console baudrate for MPC837XEMDS is 115200bps.