Chapter1 Zynq Basics

Build Overview

Xilinx zynq platform 整個build流程大致是 (以zynq zc702為例)

格式化SD card成FAT32格式 Reference
Download版子的pre-built部分和source 這裡面boot.bin和 devicetree.dtb都已經編譯好可以直接拿來放進SD card用
SD card放入我們的uramdisk.image.gz和相關library及軟體(uvcstremer, cpabe, qt_img, ...)

更改環境變數以及開機script In /etc/init.d/rcS

 //mount /dev/mmcblk0p1 /home/delta  
 mount /dev/mmcblk0 /home/delta

In /etc/init.d/rcS 的 IP address和設定

 ifconfig eth0 140.113.212.99 netmask 255.255.255.0
 route add default gw 140.113.212.254

In /etc/profile

 export LD_LIBRARY_PATH = .....:/home/delta/prj

(這部分每次開機要重設如果要永久寫入要重編uramdisk.image.gz 詳見後)

進到/home/delta/prj

 ./uvcstreamer-master_arm -n -p 8001 -w ./www -r 1280x720 
 (-p 為port -r 為resolution)

各部分建置維護

修改Rootfilesystem
修改boot.bin 有附hardware vivado project 可照流程重新建bitstream & fsbl這兩個檔 uboot xilinx github有 maintain fork 持續更新
修改kernel xilinx github有持續maintaㄛn linux kernel fork 官網boot.bin中kernel為3.19版
修改 devicetree 和kernel 同樣xilinx github有 maintain fork

About Each Part

Boot.bin

Board specific file contains MAC address for the internet, so you need a unique one!!

First Stage Boot Loader (fsbl) (board-specific)

Initialize ARM processor and DRAM controller, setting the PLL coefficients etc. http://www.wiki.xilinx.com/Build+FSBL (Generate dircetly from SDK template fsbl.elf, so you need to use the Xilinx IDE to create a project and then use their Codesourcery gcc toolchain to compile, source code editable) But that alone would not get you any further. Hence a common boot image consists of an FSBL and U-Boot The bootgen utility uses the description from the boot.bif file to create the final boot.bin

bootgen -image boot.bif -o i boot.bin

(File order does matter!!)

U-boot (ssbl, open source project) Provides console interface to execute commands or macros, thus it is suitable for debugging if the system is crash after upgrading some part of SD card. You can clone it from Xilinx git repository using the git clone command git clone git://git.xilinx.com/u-boot-xlnx.git

Let's look the source code to see how to boot using U-boot, below is a common configuration to boot from SD card.

modeboot:
run sdboot
sdboot: 
mmcinfo; 
fatload mmc 0 0x8000 zImage; 
fatload mmc 0 0x1000000 devicetree.dtb; 
fatload mmc 0 0x2000000 ramdisk32M.image.gz;

Linux kernel begins executing from memory at address 0x8000 where it is expected to find the device tree at address 0x1000000 and the root file system at address 0x2000000

The other commn configuration is where the default size of compressed ramdisk is limited to 10MB

u-boot> fatload mmc 0 0x3000000 uImage
u-boot> fatload mmc 0 0x2A00000 devicetree.dtb
u-boot> fatload mmc 0 0x2000000 uramdisk.image.gz
u-boot> bootm 0x3000000 0x2000000 0x2A00000

zImage

This is the linux kernel, compiled from: github. linux-xlnx.git It is special Kbuild system to handle complex configuration

For miniitx

git clone https://github.com/analogdevicesinc/linux.git
cd linux
git checkout xcomm_zynq
# For AD-FMCOMMS2-EBZ use
# git checkout xcomm_zynq 
export ARCH=arm
export CROSS_COMPILE=/path/to/your/arm/cross-compiler
make zynq_xcomm_adv7511_defconfig
#
# configuration written to .config
#
make uImage LOADADDR=0x00008000
  ...
  OBJCOPY arch/arm/boot/uImage
  Kernel: arch/arm/boot/uImage is ready

For zc702

git clone https://github.com/Xilinx/linux-xlnx.git
cd linux-xlnx
export ARCH=arm
export CROSS_COMPILE=/path/to/your/arm/cross-compiler
make xilinx_zynq_defconfig
# To enable USB gadget in menuconfig


make uImage LOADADDR=0x00008000

ramdisk (rootfilesystem)

This is created from the files linux-xlnx.git or some partner http://www.wiki.xilinx.com/Linux Kernel can mount a block device image as a RAM Disk (EXT3) Kernel can mount a partition fo the SD card (FAT32)

gunzip ramdisk8M.image.gz
mkdir tmp
sudo mount –o loop ramdisk8M.image tmp
cd tmp

#modification

sudo umount tmp
gzip -9 ramdisk8M.image

http://www.wiki.xilinx.com/Build+and+Modify+a+Rootfs

The default ramdisk is 16MB or 8MB (ucompressed). If you want to expand the ramdisk size, follow the below instructions and remember you have to rebuilt the kernel with new config http://www.wiki.xilinx.com/Expanding+File+System

Devicetree.dtb (board-specific)

This is device tree specification of peripherals (Needed since most peripherials are not discoverable through runtime probing) The devicetree compiler source code is part of the Linux kernel source code. Here is how to build the devicetree compiler without building the entire kernel:

http://www.wiki.xilinx.com/Build+Device+Tree+Blob

> make zynq-zed-adv7511-xcomm.dtb
DTC     arch/arm/boot/zynq-zed-adv7511-xcomm.dtb
DTC: dts->dtb  on file "arch/arm/boot/dts/zynq-zed-adv7511-xcomm.dts"

Notice: Start from kernel 3.19, ZYNQ USB driver was removed since there was already a different driver for the same IP core which is used now. The driver that is now used is the chipidea driver. Make sure that you have it enabled in your kernel config (CONFIG_USB_CHIPIDEA). The xcomm_zynq_adv7511_defconfig has it enabled by default.

However, the USB device is now configured for OTG mode by default, this means in order to use the USB port in host mode you need a proper OTG adapter. The cable has to pull the ID to GND. If you do not have such a cable you can add the 'dr_mode = "host";' property to the usb node in the devicetree similar to this https://github.com/analogdevicesinc/linux/blob/xcomm_zynq/arch/arm/boot/dts/zynq-zed-adv7511-imageon-loopback.dts#L153L155

Zynq_HW_SW_Codesign