This README file contains information on building and booting
Yocto for the Xilinx ZC702 board.

SOC & board features

	Feature 	Support	Notes
	UP		yes
	SMP		yes
	TTC		yes	3-channel timer
	UART		yes	only second UART via CP2103 USB converter
	PL330		yes	DMA controller
	SLCR		yes	clock control, reset and MIO (pin mux)
	GPIO		yes
	DEVCFG		yes	PL control and bitstream upload; untested
	EMAC		yes	Ethernet controller
	88E1116R	yes	Ethernet PHY (Marvell); on board
	SDHCI		yes
	QSPI		yes
	N25Q128A	yes	QSPI flash; on board
	SPI		no	driver included; no devices connected
	NAND		no	driver included; no devices connected
	I2C		yes
	PCA9548		yes	I2C mux; on board
	Si570		yes	I2C programmable oscillator; on board
	ADV7511		no	I2C HDMI transmitter; on board
	TCA6416		yes	I2C GPIO ; on board
	UCD9248		no	I2C 3x Digital PWM System Controller; on board
	RTC8564		yes	I2C Real Time Clock; on board
	M24C08		no	I2C EEPROM; on board
				RevB boards have a PCB layout issue, should
				work on fixed board as there is a driver in
				the kernel
	USB		yes	host, device and OTG modes
	XADC		yes	only internal sensors (temp, supply voltages)
				and dedicated external channel supported

Building

In order to build Yocto for the ZC702 board, you need to add the meta-zynq layer
to your bblayers.conf file (variable BBLAYERS) and set MACHINE = "zynq" in the local.conf
file. You can then use the following bitbake targets:

- core-image-minimal, to build a root image suitable for ramdisk (ext2.bz2) or QSPI flash
	(jffs2). This image contains mtd-utils in addition to the standard core-image-minimal
	packages, but no modules. It is limited to 8MB in size.
- core-image-zynq, to build a root image suitable for SD-card or USB (ext3). This image
	contains a lot of extra utilities, as well as the kernel modules.
- linux-yocto, to build a kernel in uImage format as well as a device tree.

Booting from SD card

The jumper configuration for booting from SD card is: J20 2-3, J21 2-3, J22 1-2, J25 1-2,
	J26 2-3, J27 1-2, J28 1-2. The ROM bootloader looks for a BOOT.BIN file in the root
	of the first partition of the card, loads it and executes it. The partition has to 
	be in VFAT format. The card that comes with the board contains an U-Boot loader in 
	the BOOT.BIN file.

Booting from QSPI flash

The jumper configuration for booting from the QSPI flash is: J20 2-3, J21 2-3, J22 2-3,
	J25 1-2, J26 2-3, J27 1-2, J28 1-2. The ROM bootloader loads the secondary bootloader
	from the start of the QSPI flash device and executes it. You can write the BOOT.BIN
	file that comes with the SD card with the following sequence of U-Boot commands,
	before setting the jumpers for QSPI boot:

	mmcinfo
	fatload mmc 0 0x100000 BOOT.BIN
	sf probe 0
	sf write 0x100000 0 ${filesize}

Booting the core-image-minimal image as a ramdisk

The devicetree node "chosen" is used to set the boot line for the kernel. Load the correct dtb
	file from the boot media. The following example uses network loading, if you want to 
	load the files from the SD card or the QSPI flash please consult the U-Boot documentation.
	The files referenced can be found in tmp/deploy/images and are assumed to be copied to the
	root location used by the TFTP server. 

	setenv ipaddr 10.0.0.2
	setenv serverip 10.0.0.1

	tftp 0x1000000 uImage-zynq-zc702_ram.dtb
	tftp 0x2000000 core-image-minimal-zynq.ext2.bz2
	tftp tftp 0x1010000 uImage-zynq.bin

	bootm 0x1010000  - 0x1000000

Booting the core-image-minimal image as a JFFS2 volume

The devicetree node "chosen" is used to set the boot line for the kernel. Load the correct dtb
	file (uImage-zynq-zc702_qspi.dtb) from the boot media. If you don't have the correct
	dtb file, you can modify the one you have in U-Boot :

	tftp 0x1000000 uImage-zynq-zc702_ram.dtb
	fdt addr 0x1000000
	fdt print /chosen
	setenv bootargs console=ttyPS0,115200 earlyprintk root=/dev/mtdblock6 rw rootfstype=jffs2 rootwait
	fdt chosen
	fdt print /chosen

The root image can be programmed directly from U-Boot:
	tftp 0x2000000 core-image-minimal-zynq.jffs2
	sf probe 0
	sf erase 0x800000 0x800000
	sf write 0x2000000 0x800000 ${filesize}

You only need to do this once. Afterwards, you can either load the correct dtb or
	modify the old dtb, load the uImage and do

	bootm 0x1010000  - 0x1000000

Booting the core-image-zynq as a SD card partition

See instructions above. The correct dtb file is uImage-zynq-zc702_sd.dtb and the boot line is:

	console=ttyPS0,115200 earlyprintk root=/dev/mmcblk0p2 ro rootwait

This assumes that the root partition is the second one, as the first one might be used for the
	bootloader. You can write the core-image-zynq-zynq.ext3 file directly to the partition
	using dd or cat. Save the content of the initial partition first, resize it or erase it
	then create a small VFAT partition and a Linux partition at least 256MB in size. Format 
	the first partition as VFAT and write BOOT.BIN to the first partition as a file then
	write the ext3 image to the second partition. You can also format the second partition
	with your favorite settings, mount it and untar core-image-zynq-zynq.tar.bz2 

USB interface

The USB interface on the ZC702 board can work in host, peripheral and otg mode. The jumper
	configuration for host (default) mode is: J7 ON, J33 2-3, J34 2-3, J35 1-2, J36 1-2.
	For device mode, remove J7 and move J33 to 1-2. For OTG mode, remove J34. If you don't
	have a cable with the ID pin grounded for starting in host mode, ground J34 pin 2. Also,
	you need to modify the devicetree property dr_mode of /amba/usb/ :

	tftp 0x1000000 uImage-zynq.dtb
	fdt addr 0x1000000
	fdt set /amba/usb dr_mode peripheral

	or

	fdt set /amba/usb dr_mode otg

You can also modify the devicetree permanently, by editing the devicetree source file zc702.dtsi
	and using the dtc program to compile a dtb:

	dtc -I dts -O dtb zc702_ram.dts > uImage-zynq-zc702_sd.dtb

	You can access the dtc program within the devshell:

	bitbake linux-yocto -c devshell