[Linux]How to execute reboot in the Linux driver module

 void rebootBMC(void) {
    int ret;
    char *cmd[2], *path[4];

    cmd[0] = "/sbin/reboot";
    cmd[1] = NULL;
    path[0] = "HOME=/";
    path[1] = "PWD=/";
    path[2] = "PATH=/sbin";
    path[3] = NULL;
    ret = call_usermodehelper(cnd[0], cnd, path, 0);
    printk(KERN_INFO "reboot to enable SMBus Sideband LAN (ret = %d).\n",  ret);
}

You can fill the parameter into cmd[1] and the cmd and path arrays should end with "NULL.

[Linux]Redirect stderr into stdout

Add 2>&1 in the command line.

e.g. ipmitool -H 10.99.6.8 -U USERID -P PASSW0RD sel 2>&1 | awk 'NR==1{print $2}'

[Linux]Read/Write config file in the driver module

#include linux/string.h

static int WriteBondConfToNCSI(void){
struct file *fp;
char buf[128],  *substring;
int indexofsubstring = 0;
mm_segment_t fs;

fp=filp_open("/conf/bond.conf",O_RDONLY,0);

fs = get_fs();
// Set segment descriptor associated to kernel space
set_fs(get_ds());

memset(buf, 0, sizeof(buf));

// Read the file
fp->f_op->read(fp, buf, 128, &fp->f_pos);
set_fs(fs);
filp_close(fp,NULL);

fp=filp_open("/conf/bond.conf",O_WRONLY | O_TRUNC,0);

substring = strstr(buf, "eth");
indexofsubstring = substring - buf;
buf[indexofsubstring+3] = '0';

fs = get_fs();
// Set segment descriptor associated to kernel space
set_fs(get_ds());

fp->f_op->write(fp, (char *)buf, strlen(buf), &fp->f_pos);

set_fs(fs);
filp_close(fp,NULL);

return 0;
}

如果想判斷某檔案是否存在，可利用下列方式:
filep=filp_open("/tmp/aa",O_RDONLY,0);
if(IS_ERR(filep)){
//Not exist
}
else{
//Exist
}

不可使用if(filep == NULL){}

[Linux]Mount the image file with jffs2 file system in the Linux OS.

1. modprobe mtdblock

2. modprobe mtdram total_size=512k erase_size=64k

3. dd if=jffs2.img of=/dev/mtdblock0

4. mount -t jffs2 /dev/mtdblock0 /mnt/

2014春節

[LINUX]Something for ipmi driver and ipmitool

1. ipmi driver的source code放置於/usr/src/kernels/3.10.4-19_00032_g982b172/driver/char/ipmi下。

2.於/usr/src/kernels/3.10.4-19_00032_g982b172/使用下面command可以complie ipmi driver
make M=driver/char/ipmi

3. ipmi driver不允許user直接送下列的raw commnd，
   raw 0x06 0x33 - Get Message
   raw 0x06 0x34 - Send Message
   raw 0x06 0x35 - Read Event Message Buffer - 可使用ipmiutil getevent取得event

4. 如果要使用ipmitool -t 0x2c -b 6 raw 0x06 0x01，則必須建立nmchannel.i，因為ipmi driver在啟動時，會送Get Channel Info command去scan all channel，如果沒有nm channel的info，ipmi driver即不會傳送bridge command to BMC。

Build SPX in ubuntu

1. Change bash
unlink /bin/sh
ln ‐sf bash /bin/sh

2. install the necessary packages.
apt‐get install libtool
apt‐get install zlib1g
apt‐get install zlib1g‐dev
apt‐get install libcurl4‐gnutls‐dev