Stay Hungry, Stay Foolish

zfs

2026-06-26T14:11:57.848+08:00

~# zpool import

pool: freenas_xxx

id: 1132200382232156645

state: ONLINE

status: The pool was last accessed by another system.

action: The pool can be imported using its name or numeric identifier and

the '-f' flag.

see: https://openzfs.github.io/openzfs-docs/msg/ZFS-8000-EY

config:

freenas_xxx ONLINE

raidz2-0 ONLINE

sda ONLINE

sdc ONLINE

sdd ONLINE

sdb ONLINE

~# zpool import -o readonly=on -R /tmp freenas_xxx

cannot import 'freenas_fuxing_1st_rd': pool was previously in use from another system.

Last accessed by freenas.fuxing (hostid=fe2c2f4) at Sun Dec 1 07:59:49 2019

The pool can be imported, use 'zpool import -f' to import the pool.

>>>>>

~# zpool import -f -o readonly=on -R /tmp freenas_xxx

// check zpool status

~# zpool status

// umount zpool

~# zpool export freenas_xxx

dpdk-pktgen

2025-03-06T14:10:00.005+08:00

C shared or static library 'bsd' not found

Soltuion: make menuconfig -> enable libbsd

Program python3 found: YES (/work/marvell-sdk/cn10ka-switches-release-output/host/bin/python3)

Library rte_net_i40e found: YES

Library rte_net_ixgbe found: YES

Library rte_net_ice found: YES

Library rte_bus_vdev found: YES

Run-time dependency threads found: YES

Run-time dependency numa found: YES 2.0.14

Run-time dependency pcap found: YES 1.10.1

Library dl found: YES

Library m found: YES

../cn10ka-switches-release-output/build/dpdk-pktgen-24.10.3/app/meson.build:53:0: ERROR: C shared or static library 'bsd' not found

A full log can be found at /work/marvell-sdk/cn10ka-switches-release-output/build/dpdk-pktgen-24.10.3/build/meson-logs/meson-log.txt

make[1]: *** [package/pkg-generic.mk:283: /work/marvell-sdk/cn10ka-switches-release-output/build/dpdk-pktgen-24.10.3/.stamp_configured] Error 1

make: *** [Makefile:23: _all] Error 2

Ubuntu 22.04 LTS

2025-02-19T15:54:00.004+08:00

VIM issue: https://vi.stackexchange.com/questions/29529/escape-sequences-showing-up-within-vi
Install nVidia driver

sudo add-apt-repository ppa:graphics-drivers
sudo apt update
Open "Software Update" to install the driver
Reference: https://askubuntu.com/questions/1533273/nvidia-560-drivers-not-available-in-ubuntu-24-04

PTP

2024-12-17T10:13:00.001+08:00

PTP Introduction

https://networklessons.com/cisco/ccnp-encor-350-401/introduction-to-precision-time-protocol-ptp

Configuring PTP using ptp4l

https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/7/html/system_administrators_guide/ch-configuring_ptp_using_ptp4l#sec-Using_PTP_with_Multiple_Interfaces

ffmpeg

2024-12-17T10:11:00.005+08:00

Dump RTSP to file

"ffmpeg -i rtsp://@192.168.241.1:62156 -acodec copy -vcodec copy c:/abc.mp4"

https://stackoverflow.com/questions/16259588/how-to-dump-raw-rtsp-stream-to-file

Continuously produce 1 second videos

"ffmpeg -framerate 5 -i /tmp/ffmpeg_pipe -c:v libx264 -g 5 -f segment -segment_time 1 "output_%04d.mp4""

-g 5 argument forces a key frame every 5 frames

https://superuser.com/questions/1812357/how-can-i-setup-ffmpeg-to-continuously-produce-1-second-videos-from-piped-jpgs

Run a ffmpeg process in the background

"nohup ffmpeg_cmd 2>/dev/null > /dev/null &"
https://stackoverflow.com/questions/1198052/run-a-ffmpeg-process-in-the-background

Transfer mp4 to mkv

ffmpeg -i aaa.mp4 -c copy aaa.mkv
https://stackoverflow.com/questions/65525078/does-converting-mp4-to-mkv-change-data-fidelity

minicom with Kermit

2024-12-09T10:48:00.001+08:00

1. sudo apt-get install ckermit

2. Edit ~/.kermrc

=====

set carrier-watch off
set prefixing all
set parity none
set stop-bits 1
set modem none
set file type bin
set file name lit

set flow-control none

=====

3. In minicom, "ctrl" -> "a" -> "o", change g and h as below

=====

G --> /usr/bin/kermit -i -l %f -b %b -s Y U Y N N

H --> /usr/bin/kermit -i -l %f -b %b -r N D Y N N

=====

4. in minicom, "Save setup as dfl"

5. exit minicom

6. source ~/.kermrc

7. sudo minicom -D /dev/ttyUSBx

8 "ctrl" -> "s" -> kermit -> select file to transfer

Referebce

http://lazyflai.blogspot.com/2010/06/linuxminiconkermit.html

Startup

2019-03-29T09:40:00.004+08:00

Setup Time Machine under Ubuntu

2019-02-12T16:42:00.001+08:00

低成本搭建Time Machine 服务器

Using libusb without udev and usbfs

2019-01-30T18:49:00.001+08:00

Due to CONFIG_USB_DEVICEFS is obsoleted in Kernel 3.10.x. To enable libusb to access the specific USB device, ex: under busybox mdev enrionment, it should be mapped to /dev/bus/usb/00x/00x manually.

libusb download link
Build libusb and disable udev

./configure --host=$(HOST) --target=$(TARGET) --disable-udev --prefix=$(LIB_TEMP_DIR)

Sample script to add specific USB node to "/dev/bus/usb/".

#!/bin/sh

for sysdevpath in $(find /sys/bus/usb/devices/usb*/ -name dev); do
    syspath="${sysdevpath%/dev}";
    if [ -e ${syspath}/busnum ]; then
        dev=`cat ${syspath}/dev`
        busnum=`cat ${syspath}/busnum`
        devnum=`cat ${syspath}/devnum`
        idVendor=`cat ${syspath}/idVendor`
        idProduct=`cat ${syspath}/idProduct`

        BUSNUM=`printf "%03d" ${busnum}`
        DEVNUM=`printf "%03d" ${devnum}`

        NODE_MASTER=`echo $dev | cut -d ":" -f1`
        NODE_MINOR=`echo $dev | cut -d ":" -f2`

        #devname=`printf "bus/usb/%03d/%03d" ${busnum} ${devnum}`
        #echo "syspath = ${syspath}, devname = ${devname}, dev = ${dev}"
        #echo "idVendor = ${idVendor}, idProduct = ${idProduct}"
        #echo "node_master = ${node_master}, node_minor = ${node_minor}"

        if [ ${idVendor} == "Vendor_id_you_want" ] && [ ${idProduct} == "product_id_you_want" ]; then
            echo "found................."
            if [ -e /dev/bus/usb/${BUSNUM} ]; then
                rm -fr /dev/bus/usb/${BUSNUM}
            fi

            mkdir -p /dev/bus/usb/${BUSNUM}
            mknod /dev/bus/usb/${BUSNUM}/${DEVNUM} c ${NODE_MASTER} ${NODE_MINOR}
        fi
    else
        continue;
    fi
done;

Reference

Start dhcpd on more than one NIC

2018-04-16T16:12:00.001+08:00

Bridge all interfaces to a bridge, then run udhcpd on the bridge interface.

# insmod /lib/module/3.x.x/kernel/.../wifi_driver.ko
# ifconfig ra0 up
# brctl addif br0 ra0
device ra0 entered promiscuous mode
br0: port 7(ra0) entered forwarding state
br0: port 7(ra0) entered forwarding state
# br0: port 7(ra0) entered forwarding state
MtAsicACQueue: Write CR:21510, Value=10421
MtAsicACQueue: Write CR:21500, Value=10421
MtAsicACQueue: Write CR:21510, Value=10421
MtAsicACQueue: Write CR:21500, Value=10421
Rcv Wcid(1) AddBAReq
Start Seq = 00000000
sending OFFER of 192.168.1.33
BA - Send ADDBA request. StartSeq = 0, FrameLen = 33. BufSize = 8
BA - Send ADDBA request. StartSeq = 200, FrameLen = 33. BufSize = 8
sending OFFER of 192.168.1.33
sending ACK to 192.168.1.33

# ping 192.168.1.33
PING 192.168.1.33 (192.168.1.33): 56 data bytes
64 bytes from 192.168.1.33: seq=0 ttl=64 time=31.349 ms
64 bytes from 192.168.1.33: seq=2 ttl=64 time=155.953 ms
64 bytes from 192.168.1.33: seq=3 ttl=64 time=165.323 ms
64 bytes from 192.168.1.33: seq=4 ttl=64 time=120.031 ms
^C
--- 192.168.1.33 ping statistics ---
5 packets transmitted, 4 packets received, 20% packet loss
round-trip min/avg/max = 31.349/118.164/165.323 ms
How to add interface to a bridge.

NAND flash offset calculation

2018-01-05T16:46:00.001+08:00

NAND flash information

512MB
8192 blocks
1 block = 64 pages
1 page = (2K + 6) bytes

bad block information

[NAND]select ecc bit:4, sparesize :64 spare_per_sector=16
Scanning device for bad blocks
Bad eraseblock 546 at 0x000004440000
Bad eraseblock 2868 at 0x000016680000
Bad eraseblock 3890 at 0x00001e640000
Signature matched and data read!

Dump bad block, 0x000004440000, data from u-boot

page number = (4440000h/800h) = 8880h

4440000h = bad block offset
800h = 2048 bytes

# nand page 8880
page 0x8880:
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

oob:
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

Write data to error block

# nand write 16680000 34
write offs 0x16680000, len 0x2
ranand_read: skip reading a fact bad block 16680000 -> 166a0000
..ranand_erase: start:16680000, len:20000 
ranand_erase: attempt to erase a fact bad block at 0x16680000
.(5192)offs=375914496 piece=0 piece_size=2 rc=1
bad block: 16680000, try next: 166a0000
..ranand_erase: start:166a0000, len:20000 
.(5192)offs=375914496 piece=0 piece_size=2 rc=0
Done!
write succeed

Read/Write data to good block next bad block

# nand erase 166a0000 16
erase addr=166A0000, len=22
ranand_erase: start:166a0000, len:16 
.erase finish
# nand write 166a0000 34  
write offs 0x166a0000, len 0x1
..ranand_erase: start:166a0000, len:20000 
.(5192)offs=376045568 piece=0 piece_size=1 rc=0
Done!
write succeed
# nand read 166a0000 16
pagemask=0003FFFF, chipize=1FF80000
(5286) chip->page_shift=11
read len: 22
34 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 

# nand page 2cd40                    // 2cd40h = 166a0000h/800h
page 0x2cd40:
34 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff

ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff

ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff

ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff

oob:
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
28 0c 22 f0 8d 1d fd ff 26 20 98 1b 87 6e fc ff 26 20 98 1b 87 6e fc ff 26 20 98 1b 87 6e fc ff

nodejs relative

2017-10-07T15:47:00.003+08:00

1. install n to management nodejs
1.1 $ sudo npm install -g n
1.2 $ n // check version
1.3 $ sudo n latest // install latest version
1.4 $ sudo n stable // install stable version
1.5 $ n rm 0.0.x // remove 0.0.x version
1.6 $ n use 0.0.x test.js // use 0.0.x version
1.7 利用n和nvm管理Node的版本

openwrt bleeding_edge

2017-09-06T14:17:00.000+08:00

How to add customized files to openwrt.

/files
/files/etc/passwd
/files/etc/shadow

[OpenWRT][Add custom user in image]

How to fix following "unicode/uversion.h: No such file or directory" error

In file included from ../deps/v8/src/assembler.cc:95:0:
../deps/v8/src/intl.h:14:30: fatal error: unicode/uversion.h: No such file or directory
compilation terminated.

disable i18n feature first by "make menuconfig -> Langues -> Node.js -> Configuration -> Enable i18n features"
make openwrt
enable i18n feature

Lora gateway feeds
change default settings from LEDE

支持Homekit路由器系统的编译-LEDE

How to enable MIPS FPU emulator in openwrt

2017-08-24T10:43:00.000+08:00

Two ways to enable MIPS FPU emulator in openwrt

make menuconfig

Advanced configuration option (for developers) --> Target options --> Use software floating point by default

make kernel_menuconfig

Kernel Type --> MIPS FPU Emulator

Check if FPU emulator is enabled by
root@OpenWrt:/# ls /sys/kernel/debug/mips/
fpuemustats unaligned_action unaligned_instructions

Testing Result:

Step 1: | V | V | X |
Step 2: | X | V | V |
Result: | X | V | V |

Conclusion:
Only turn on step2 can enable MIPS FPU emulator

Note: Enable MIPS FPU emulator fixes "Illegal Instruction" while running applications (like node.js).

Reference:

Add diffie-hellman-group1-sha1 back to openssh-server (OpenSSH_7.2p2)

2016-08-01T14:53:00.003+08:00

sshd log is storaged at "/var/log/auth.log".


Unable to negotiate with 127.0.0.1: no matching key exchange method found.
Their offer: diffie-hellman-group1-sha1

Add following lines to /etc/ssh/sshd_config


KexAlgorithms diffie-hellman-group1-sha1,curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1
Ciphers 3des-cbc,blowfish-cbc,aes128-cbc,aes128-ctr,aes256-ctr

regenerate keys by "ssh-keygen -A"
Restart sshd server by "service sshd restart"
Reconnect from client by scp/ssh again.
Reference

IPQ806X

2016-03-14T15:55:00.000+08:00

Enable scp access

sudo apt-get update
sudo apt-get install openssh-server
sudo ufw allow 22

Simple test script

copy command: "scp username@192.168.1.100:/tftpboot/username/test.sh ."
execute command: "source test.sh 2>&1 | tee test.log"

#!/bin/sh

echo "iperf testing"
iperf -c 192.168.1.100 -t 30

echo "Setting WiFi AP"
uci set wireless.@wifi-device[0].disabled=0
uci set wireless.@wifi-device[0].hwmode=11ac
uci set wireless.@wifi-device[0].htmode=VHT80
uci set wireless.@wifi-device[0].channel=44
uci set wireless.@wifi-iface[0].ssid=AK_5G_1
uci set wireless.@wifi-device[1].disabled=0
uci set wireless.@wifi-device[1].hwmode=11ng
uci set wireless.@wifi-device[1].htmode=HT40
uci set wireless.@wifi-device[1].channel=6
uci set wireless.@wifi-iface[1].ssid=AK_2G
uci set wireless.@wifi-device[2].disabled=0
uci set wireless.@wifi-device[2].hwmode=11ac
uci set wireless.@wifi-device[2].htmode=VHT80
uci set wireless.@wifi-device[2].channel=44
uci set wireless.@wifi-iface[2].ssid=AK_5G_2
uci set wirelss; wifi

echo "Testing nand-flash"
lmdd if=/dev/mtd0 of=/tmp/test.bin bs=4096 count=1000
lmdd if=/tmp/test.bin of=/dev/mtd0 bs=4096 count=1000

echo "Testing nor-flash"
lmdd if=/dev/mtd12 of=/tmp/kernel.bin bs=4096
lmdd if=/tmp/kernel.bin of=/dev/mtd12 bs=4096

echo "Testing LEDs"
echo 1 > /sys/class/leds/ap148:blue:status/brightness
echo 0 > /sys/class/leds/ap148:white:status/brightness
sleep 3
echo 0 > /sys/class/leds/ap148:blue:status/brightness
echo 1 > /sys/class/leds/ap148:white:status/brightness
sleep 3
echo 1 > /sys/class/leds/ap148:blue:status/brightness
echo 1 > /sys/class/leds/ap148:white:status/brightness
sleep 3
echo 0 > /sys/class/leds/ap148:blue:status/brightness
echo 0 > /sys/class/leds/ap148:white:status/brightness

echo "Press WPS before leaving"
#just push wps, target will act WPS PUSH BUTTON EVENT DETECTED
#event_test /dev/input/event0

DDR3 speed calculation

equtation: vco = ref * (L + M/N)/(p*q)

 devmem2 0x00903184 0x4000042A  
 devmem2 0x00903188 0x10  
 devmem2 0x0090318c 0x19

 L = 0x2A, M=0x10, N=0x19  
 25M * (42 + 16/25)/(2*1) = 533 MHz

Reference document: 80_Y6477_22_IPQ806X_CLOCK_CONTROLLER_PROGRAMMING_REFERENCE.pdf

Merge git repositories from old ones.

2016-03-01T15:32:00.000+08:00

Merge git repositories from old ones.

 
 # like to have git structure as below
 root ---> for_uboot ---> for_uboot_test1
      |              |--> for_uboot_test2
      |--> for_kernel ---> for_kernel_test1
                      |--> for_kernel_test2
 # clone empty repository as final target  
 ## add one file as init commit  
 # git checkout -b for_uboot  
 ## add one file for u_boot root  
 # git push origin for_uboot  
 # git remote add old_uboot git@github.com:xxxx/old_uboot_repository  
 # git fetch old_uboot  
 # git checkout -b for_uboot_test1  
 # git merge old_uboot/test1  
 # git push --set-upstream origin for_uboot_test1  
 # git checkout for_uboot     // add uboot_test2  
 # git checkout -b for_uboot_test2  
 # git merge old_uboot/test2  
 # git push --set-upstream origin for_uboot_test2  
 # git checkout master // add kernel  
 # git checkout -b for_kernel  
 ## add file to for_kernel root  
 # git remote add old_kernel git@github.com:xxxx/old_kernel_repository  
 # git fetch old_kernel  
 # git checkout -b for_kernel_test1  
 # git merge old_kernel/test1  
 # git push --set-upstream origin for_kernel_test1  
 # git checkout for_kernel // add old_test2  
 # git checkout -b for_kernel_test2  
 # git merge old_kernel/test2  
 # git push --set-upstream origin for_kernel_test2

U-boot standalone application

2016-02-17T13:13:00.001+08:00

U-Boot Standalone Applications
U-Boot Licensing

NOTE! This license does not cover the so-called "standalone" applications that use U-Boot services by means of the jump table provided by U-Boot exactly for this purpose - this is merely considered normal use of U-Boot, and does not fall under the heading of "derived work" -- see file Licenses/Exceptions for details.

Design Notes on Exporting U-Boot Functions to Standalone Applications

The functions are exported by U-Boot via a jump table.
The pointer to the jump table is passed to the application in a machine-dependent way.
The application should call the app_startup() function before any call to the exported functions.

If some functions are added before entry point, u-boot standalone application will not work normally. Using ${CROSS_COMPILE}nm to get the offset and run from it.

 $ ${CROSS_COMPILE}nm -n examples/hello_world  
 0000000000040004 T testfunc  
 0000000000040058 T hello_world  
 000000000004016c t dummy  
 ...

My standalone program does not work

Build a u-boot standalone outside of u-boot

 # Makefile for simple standalone application  
 # to run under U-boot Tom Trebisky 4-15-2015  
 CCX = arm-linux-gnu-gcc  
 COPTS = -nostdinc -fno-builtin -Os -marm -march=armv7-a -I.  
 CC = $(CCX) $(COPTS)  
 # It is a bug that we cannot invoke gcc to do this,  
 # but doing this directly gets the job done.  
 LD = arm-linux-gnu-ld.bfd  
 BIN = arm-linux-gnu-objcopy -O binary  
 DUMP = arm-linux-gnu-objdump -d  
 all: hi.bin  
 install: hi.bin  
      cp hi.bin /var/lib/tftpboot/hello.bin  
 dump:     hi  
      $(DUMP) hi  
 version:  
      $(CC) --version  
 hi.o: hi.c  
      $(CC) -c hi.c  
 stubs.E: stubs.c  
      $(CC) -E stubs.c  
 stubs.s: stubs.c  
      $(CC) -S stubs.c  
 stubs.o: stubs.c  
      $(CC) -c stubs.c  
 hi: hi.o stubs.o  
      $(LD) -g -Ttext 0x80300000 -e hi_there -o hi hi.o stubs.o  
 hi.bin: hi  
      $(BIN) hi hi.bin  
 clean:  
      rm -f hi.o stubs.o hi hi.bin stubs.s stubs.E

make file sample
sample lds file as below

 OUTPUT_FORMAT("elf32-littlearm", "elf32-littlearm", "elf32-littlearm")  
 OUTPUT_ARCH(arm)  
 ENTRY(hello_world)  
 MEMORY  
 {  
   ram : ORIGIN = 0x42000000, LENGTH = 16M  
 }  
 SECTIONS  
 {  
   .text :  
   {  
     *(.text)  
     *(.rodata)  
     _etext = .;  
   } > ram  
   .data :  
   {  
     _data = .;  
     *(.data)  
     _edata = .;  
   } > ram  
   .bss :  
   {  
     __bss_start = .;  
     *(.bss)  
   } > ram  
   . = ALIGN(4);  
   __bss_end = .;  
   _end = .;  
 }

Sample lds for u-boot standalone application

Sections and LDS sample

How to access global variables in standalone application

Sample command to load standalone application from u-boot as below

 set ipaddr 192.168.1.1  
 set serverip 192.168.1.100  
 tftpboot 0x42000000 hello_world.bin  
 go 0x42000000

Note the load address of command "tftpboot 0x42000000 hello_world.bin"
Set "${CROSS_COMPILE}ld -Ttext" to tftp load address as "${CROSS_COMPILE}ld -Ttext 0x42000000"

Some useful references

Swimming Articles

2016-02-17T10:25:00.001+08:00

Openwrt Relative Items

2016-02-03T14:04:00.002+08:00

How to partial build?

clean and rebuild kernel: "make target/linux/{clean,compile} V=99"
rebuild kernel: "make target/linux/compile V=99"
rebuild bootloader: "make package/uboot-ipq806x/compile V=99"

Notice, you can find following folder under package

OpenWrt build system – Usage

quilt

Quilt-Patches 整合 Script

OpenCV

2015-10-02T16:43:00.002+08:00

IplImage to Mat

 #include "opencv2/highgui/highgui"  
 #include "opencv2/core/core_c.h"  
 #include <iostream>  
 using namespace cv;  
 using namespace std;  
 void foo(void) {  
   IplImage *org_img;  
   Mat org_mat = cvarrToMat(org_img); // not copy, share memory  
   ...  
 }

Yocto Relative

2015-09-22T16:23:00.003+08:00

How to config DDR

Configure xlsx file, download from here, according to DDR chip's parameters.
Copy all the data from Realiew.inc tab to an file, ddr.inc for example.
Comment "system /16 0x020bc000 = 0x30
Follow stress test tool doc to perform the stress test.
Write the result data back to u-boot.

How to add LEDS_PWM

Make sure the kernel configuration CONFIG_LEDS_PWM resp. CONFIG_LEDS_GPIO is enabled.

 pwmleds {  
   compatible = "pwm-leds";  
   led1 {  
     label = "test-green-led";  
     pwms = <&pwm1 1 5000000 0>; // frequency in ns  
     max-brightness = <255>;  
   };  
 };

PWM (Linux)

i.mx6 pinctrl information

fsl,imx-pinctrl.txt

 Bits used for CONFIG:  
 NO_PAD_CTL(1 << 31): indicate this pin does not need config.  
 SION(1 << 30): Software Input On Field.  
 Force the selected mux mode input path no matter of MUX_MODE functionality. By default the input path is determined by functionality of the selected mux mode (regular).

Device Tree Customization

How to change kernel configuration?

steps

 $ bitbake linux-imx -c cleansstate  
 $ bitbake linux-imx -c menuconfig  
 <enable some configurations>  
 $ bitbake linux-imx -c diffconfig  
 $cp /mnt/data/imx6/fsl-release-bsp-3-10-53/build-x11/tmp/work/imx6qsabresd-poky-linux-gnueabi/linux-imx/3.10.53-r0/fragment.cfg ../sources/meta-xxx/recipes-kernel/linux/linux-imx/pci.cfg  
 <add following in bbappend file>  
 ...  
 SRC_URI += "file://pci.cfg"  
 ...  
 do_configure_append() {  
     #this is run from  
     #./tmp/work/imx6qsabresd-poky-linux-gnueabi/linux-imx/3.10.53-r0/git  
     cat ../*.cfg >> ${B}/.config  
 }  
 $ bitbake linux-imx -c cleansstate  
 $ bitbake -c configure -f linux-imx  
 $ bitbake -c compile -f linux-imx

Changing the Kernel configuration for i.MX6 SABRE

How to add u-boot patches?

create layer (yocto-layer create imx6dlXXX)
add layer to $(yocto)/sources/base/conf/bblayers.conf
add LAYERDEPENDS_xxx = "core fsl-arm fsl-arm-extra" in $(layer)/conf/layer.conf
get u-boot patches (git format-patch -X)
create $(layer)/recipes-bsp/u-boot
create u-boot-imx_2014.04.bbappend under $(layer)/recipes-bsp/u-boot/u-boot-imx/

FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}-${PV}:" SRC_URI += "file://0001-XXX.patch"

create folder under $(layer)/recipes-bsp/u-boot/u-boot-imx-2014.04 and copy all patches to here
bitbake -c compile u-boot-imx -f
bitbake -c deploy u-boot-imx

Using BB to copy files (sample.bb)

 DESCRIPTION = "Copies files to the image"  
 LICENSE = "CLOSED"  
 FILESEXTRAPATHS_prepend := "${THISDIR}/files:"  
 SRC_URI += "file://myLib1.bin"  
 SRC_URI += "file://myLib2.bin"  
 S = "${WORKDIR}"  
 do_install() {  
  install -v -d ${D}lib/firmware/brcm/  
  install -m 755 myLib1.bin ${D}/lib/firmware/brcm/myLib1.bin  
  install -m 755 myLib2.bin ${D}/lib/firmware/brcm/myLib2.bin  
 }  
PACKAGE_ARCH_mx6 = "${MACHINE_ARCH}"

Add package to specific image in conf/local.conf

 IMAGE_INSTALL_append += "sample"

Useful commands

Check all available recipes

bitbake-layers show-recipes "*-image-*"

Add Crosswalk to Yocto project

Reference Link

Reference: Support customer board
FAQs

How to fix: Make[1]: Execvp: printf: Argument list too long

To solve this problem, be sure ‘pwd’ command prints less than 50 characters in your shell when you are in yocto-build folder.

Reference

Codility Test

2015-07-01T10:19:00.000+08:00

Lesson 1: Time Complexity

Lesson 2: Counting elements
Lesson 3: Prefix sums
Lesson 4: Sorting

Distinct

Lesson 5: Stacks and queues
Lesson 6: Leaders
Lesson 7: Maximum slice sum

Lesson 8: Prime and composite numbers

Lesson 9: Sieve of Eratosthenes

CountSemiprimes
CountNonDivisible (need to refine by sieve)

Lesson 10: Euclidean algorithm

ChocolatesByNumbers

CommonPrimeDivisors

Lesson 11: Fibonacci numbers
Lesson 12: Binary search algorithm
Lesson 13: Caterpillar method

AbsDistinct

CountDistinctSlices
MinAbsSumOfTwo

45%, double for loop

CountTriangles

Lesson 14: Greedy algorithms
Lesson 15: Dynamic programming
Lesson 99: Future training

Algorithm

2015-06-27T12:24:00.000+08:00

prefix sum

sequence of numbers: {4, 2, 2, 5, 1, 5, 8}
prefix sum: {4, 6, 8, 13, 14, 19, 27}
calculate sum between i, j

 int A[7] = {4, 2, 2, 5, 1, 5, 8};  
 int prefix_sum[7];  
 void calc_prefix_sum(void)  
 {  
   int i;  
   prefix_sum[0] = A[0];  
   for(i=1; i&lt;7; i++)  
     prefix_sum[i] = prefix_sum[i-1] + A[i];  
 }  
 int difference(int i, int j)  
 {  
   if(i == 0)  
     return prefix_sum[j];  
   return prefix_sum[j] - prefix_sum[i-1];  
 }

Reference

演算法筆記

SH-2A_Media_SDK_v2.03.00 sample

2015-06-17T17:55:00.002+08:00

sh7269 memory map sample