SystemConfig

1. toolchain
   https://sourcery.mentor.com/GNUToolchain/release858
   wget https://sourcery.mentor.com/GNUToolchain/package4571/public/arm-none-linux-gnueabi/arm-2009q1-203-arm-none-linux-gnueabi-i686-pc-linux-gnu.tar.bz2
   tar xjf arm-2009q1-203-arm-none-linux-gnueabi-i686-pc-linux-gnu.tar.bz2
2. kernel
   git clone git@github.com:cambridgehackers/device_xilinx_kernel.git
   cd device_xilinx_kernel/
   git checkout remotes/origin/december -b december
3. compile
   cd s/git/device_xilinx_kernel/
   git status
   make ARCH=arm CROSS_COMPILE=arm-none-linux-gnueabi- xilinx_zynq_portal_defconfig
   make ARCH=arm CROSS_COMPILE=arm-none-linux-gnueabi-
   ./scripts/dtc/dtc -I dts -O dtb -o foo.dtb arch/arm/boot/dts/zynq-zc702-bridge.dts
4. load
   cp arch/arm/boot/zImage foo.dtb ~
5. Making new ramdisk8M.image.gz (kernel requires that it be zero-padded to exactly 256kb)
   find . | cpio -H newc -o | gzip -9 -n > ../itemp
   dd if=/dev/zero of=../izero bs=1024 count=256
   cat ../izero >> ../itemp
   dd if=../itemp of=../imagefile.image.gz bs=1024 count=256
   rm ../itemp ../izero
6. To examine ramdisk8M.image.gz
   gzip -cd ../imagefile.image.gz | cpio -imd
7. Debugging clocks
   mount -t debugfs none /sys/kernel/debug/
   ls -l /sys/kernel/debug/clk/PS_CLK/IOPLL/FPGA1_CLK