Linux SCSI Subsystem

Reference:
http://www.t10.org
Linux SCSI Subsystem

ARM Qemu

Qemu

Qemu

[ ]# mkdir /home/qemu
[ ]# cd /home/qemu/
[ ]# git clone git://git.qemu.org/qemu.git qemu-git
[ ]# cd qemu-git/
[ ]# ./configure --target-list="arm-softmmu"
[ ]# make
[ ]# cp arm-softmmu/qemu-system-arm /usr/bin/

Or
http://download.savannah.gnu.org/releases/qemu/qemu-0.14.1.tar.gz

U-boot

[ ]# cd /home/qemu/
[ ]# wget http://ftp.denx.de/pub/u-boot/u-boot-2010.03.tar.bz2
[ ]# cd u-boot-2010.03
[ ]# make versatilepb_config ARCH=arm CROSS_COMPILE=arm-linux-
[ ]# make all ARCH=arm CROSS_COMPILE=arm-linux-
[ ]# qemu-system-arm -M versatilepb -m 128M -nographic -kernel u-boot.bin

U-Boot 2010.03 (Jun 15 2011 - 14:38:26)

DRAM: 0 kB

## Unknown FLASH on Bank 1 - Size = 0x00000000 = 0 MB

Flash: 0 kB

*** Warning - bad CRC, using default environment

In: serial

Out: serial

Err: serial

Net: SMC91111-0

VersatilePB # print

bootargs=root=/dev/nfs mem=128M ip=dhcp netdev=25,0,0xf1010000,0xf1010010,eth0

bootdelay=2

baudrate=38400

bootfile="/tftpboot/uImage"

stdin=serial

stdout=serial

stderr=serial

verify=n

ethact=SMC91111-0

Environment size: 202/8188 bytes

VersatilePB #

Simple "Hello World!" Root File System

[ ]# cd /home/qemu/
[ ]# echo "#include " > test.c
[ ]# echo "int main() {" >> test.c
[ ]# echo -e '\tprintf("Hello World!\\n");' >> test.c
[ ]# echo -e "return 0;" >> test.c
[ ]# echo "}" >> test.c

[ ]# arm-linux-gcc -static test.c -o test
[ ]# echo test | cpio -o --format=newc > rootfs

ARM Linux Versatile (ARMv5)
[ ]# cd /home/qemu/
[ ]# wget http://www.kernel.org/pub/linux/kernel/v2.6/longterm/v2.6.35/linux-2.6.35.12.tar.bz2
[ ]# tar jxvf linux-2.6.35.12.tar.bz2
[ ]# cd linux-2.6.35.12
[ ]# make ARCH=arm versatile_defconfig
[ ]# make ARCH=arm menuconfig

Enabling EABI support in the kernel. (CONFIG_AEABI=y, CONFIG_OABI_COMPAT=y)

[ ]# make ARCH=arm CROSS_COMPILE=arm-linux- all
[ ]# qemu-system-arm -M versatilepb -m 128M -kernel arch/arm/boot/zImage -initrd rootfs -serial stdio -append "console=ttyAMA0 root=/dev/ram rdinit=/test"

You can use “-nographic” instead of “-serial stdio” to launch QEMU without opening another window, but then to close it you have to type Ctrl-A and then “x”.

How to install Qemu in Linux for Versatile Express platform
Processor: Cortex A9

COREMU

Linux Kernel Tracer

# mount -t debugfs nodev /sys/kernel/debug

# cat /sys/kernel/debug/tracing/available_tracers
wakeup preemptirqsoff preemptoff irqsoff function sched_switch nop

# cat /sys/kernel/debug/tracing/current_tracer
nop

# echo sched_switch > /sys/kernel/debug/tracing/current_tracer
# cat /sys/kernel/debug/tracing/current_tracer
sched_switch

# cat /sys/kernel/debug/tracing/trace_options
noprint-parent nosym-offset nosym-addr noverbose

# echo print-parent > /sys/kernel/debug/tracing/trace_options

# echo 1 > /sys/kernel/debug/tracing/tracing_enabled
# cat /sys/kernel/debug/tracing/trace > /tmp/trace.txt
# echo 0 > /sys/kernel/debug/tracing/tracing_enabled

OProfile on ARM Linux

How to compile OProfile

binutils

[ ]#./configure \
     --target=arm-linux \
     --host=arm-linux \
     --build=i686-pc-linux-gnu \
     --enable-shared \
     --prefix=/home/oprofile/binutils-stable_bin \
     --disable-nls --disable-poison-system-directories

[ ]#make
[ ]#make install

oprofile-0.9.6

[ ]#./configure --with-linux=/home/linux-2.6.35.12-cavm1 \
     --with-kernel-support \
     --disable-optimization \
     --disable-werror \
     --target=arm-linux \
     --host=arm-linux \
     --build=i686-pc-linux-gnu \
     --enable-static \
     --with-binutils=/home/oprofile/binutils-stable_bin \
     --prefix=/home/oprofile/oprofile-0.9.6_bin

[ ]#make

How to use OProfile on ARM platform
Default: timer mode, $ modprobe oprofile timer=1
$ opcontrol --reset
$ opcontrol --init
$ opcontrol --start --vmlinux=/tmp/vmlinux --session-dir=/tmp/linux
$ opcontrol --start-daemon

$ opcontrol --dump
$ opcontrol --save=output
$ opreport --session-dir=/tmp/linux session:output -l image:/tmp/vmlinux

Sample Rate = HZ

OProfile with performance counter
$ opcontrol --callgraph=8 --separate=kernel --vmlinux=/boot/vmlinux
$ opcontrol --event=CPU_CYCLES:100000:0:1:1 \
                  --event=L1D_CACHE:100000:0:1:1 \
                  --event=L2D_CACHE:10000:0:1:1 \
                  --event=BUS_ACCESS:100000:0:1:1 \
                  --event=BUS_CYCLES:100000:0:1:1 \
                  --event=UNALIGNED_LDST_RETIRED:10000:0:1:1
$ opcontrol --init
$ opcontrol --reset
$ opcontrol --start-daemon
$ opcontrol --status
$ opcontrol --start

$ opcontrol --dump
$ opreport

Sample Rate = (CPU frequency in MHz) / (CPU_CYCLES count) / 64.
      The default value of CPU_CYCLES = 100000. The CPU_CYCLES can be changed as following               example “--event=CPU_CYCLES:125000".

      If CPU is running in 800MHz, the sample rate is 800MHz / 100000 / 64 = 125 samples per second.
   

Reference:
http://friendalways.blogspot.com/2009/11/oprofile-on-arm-linux.html

HD over Wireless

1. WiVu: Cavium
2. WiDi (Wireless Display): Intel
3. WiHD (Wireless HD): Intel, ...
4. WiGig: Wilocity (Atheros)
5. WHDI: AMIMON, Sibeam ()