Sunday, March 27, 2011

NVIDIA Legacy 96.43.xx with Linux Kernel 2.6.37 or newer

The NVIDIA driver below proven to work with Linux kernel 2.6.37:

ftp://download.nvidia.com/XFree86/Linux-x86/96.43.19/

Just run and install the *-pkg1.run

Saturday, March 26, 2011

Binary-tree test

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <time.h>

/* 
 Helper function that allocates a new node with the given data and NULL left and right pointers. 
*/ 


typedef struct node {
 int data;
 struct node *left;
 struct node *right;
} NodeT;


NodeT* NewNode(int data);
void BTreeLog(const char *fmt, ...);

typedef int (*BTreeCompFunc)(NodeT* node, void *data);

NodeT* BTreeNewNode(int data) 
{ 
 NodeT* node = (NodeT*)malloc(sizeof(NodeT));    // "new" is like "malloc" 
 node->data = data; 
 node->left = NULL; 
 node->right = NULL;
 BTreeLog("BTreeNewNode: new node=0x%X, data=%d\n", node, data);
    return(node); 
} 
     

void BTreeLog(const char *fmt, ...)
{
#ifdef __ENABLE_LOG__  
 char buf[256];
 va_list ap;
 int n;
 
 va_start(ap, fmt);
 n = vsnprintf(buf, sizeof(buf), fmt, ap);
 printf("%s", buf);
 va_end(ap);
#endif 
}


int BTreeCompare(NodeT* node, void *data)
{
 if (*((int*)data) < node->data)
  return -1;
 if (*((int*)data) > node->data)
  return 1;
 return 0;
}  
/* 
  Give a binary search tree and a number, BTreeInserts a new node 
  with the given number in the correct place in the tree. 
  Returns the new root pointer which the caller should 
  then use (the standard trick to avoid using reference 
  parameters). 
*/ 

NodeT* BTreeInsert(NodeT* node, int data, BTreeCompFunc comp)
{ 
 // 1. If the tree is empty, return a new, single node 
 if (NULL == node) 
 { 
  BTreeLog("New Entry: %d\n", data);
  return BTreeNewNode(data); 
    } 
 else { 
  // 2. Otherwise, recur down the tree 
     if (comp(node, &data) == -1) {
   /*BTreeLog("BTreeInsert: left; data=%d, node=0x%X, left=0x%X, right=0x%X\n", 
       data, node, node->left, node->right);
   */    
   node->left = BTreeInsert(node->left, data, comp); 
  } 
  else {
   /* 
   BTreeLog("BTreeInsert: right; data=%d, node=0x%X, left=0x%X, right=0x%X\n", 
       data, node, node->left, node->right);
   */    
   node->right = BTreeInsert(node->right, data, comp);
  } 
 }
 return(node); // return the (unchanged) node pointer 
}


void BTreeDeleteAll(NodeT* pNode)
{
 if (pNode)
 {
  if (pNode->left)
  {
   BTreeDeleteAll(pNode->left);
  } 
  if (pNode->right)
  {
   BTreeDeleteAll(pNode->right);
  } 
  BTreeLog("BTreeDeleteAll: pNode=0x%X, data=%d\n", pNode, pNode->data);
  free(pNode);
  //pNode->left = NULL;
  //pNode->right = NULL;
 }
}

NodeT *BTreeSearch(NodeT* pNode, int data, BTreeCompFunc comp)
{
 int cmp; 
 if (pNode) {
  cmp = comp(pNode, &data); 
  if (cmp == 0)
   return pNode;
  else 
  if (cmp == -1)
  {
   /* data < pnode->data */
   pNode = BTreeSearch(pNode->left, data, comp); 
  }
  else {
   pNode = BTreeSearch(pNode->right, data, comp);
  } 
 }
 //BTreeLog("Comp...\n");
 return pNode;
}


int main(int argc, char *argv[])
{
 NodeT* root = NULL;
 NodeT* node;
 unsigned int n,i;
 int data1, data2;
 unsigned int count;

 srand(time(NULL));
 BTreeLog("BTree demo\n");
 n = rand() % 100;
 root = BTreeInsert(root, n, BTreeCompare);
 data2 = 4750;
 n = 10000000;
 for (i=0, count=0; i<n; i++)
 {
  data1 = rand()%n;
  /* insert unique entry */
  if (BTreeSearch(root, data1, BTreeCompare) == NULL) {
   BTreeInsert(root, data1, BTreeCompare);
   count++;
  } 
 }
 BTreeInsert(root, data2, BTreeCompare);
 printf("Just inserted %d entries into Binary-tree\n", count+1);
 node = BTreeSearch(root, data2, BTreeCompare);
 printf("\n\n\n\n");
 if (node) {
  printf("!!!!!!!!!!!!!!!!!!!!!!!!Found node=0x%X for data=%d\n", node, data2);
 }
 printf("\n\n\n\n");
 BTreeDeleteAll(root);
}

Wednesday, March 23, 2011

Linux Init

LINUX INIT
--------------
This is the mother of all other userspace's processes.

Where to find it?
In the util-linux package (to be found at ftp.*.kernel.org) for simpleinit or in the sysvinit package for SysV init.

Probably also in [sunsite|metalab].unc.edu or ftp.debian.org


Title: sysvinit and utilities
Version: 2.78
Entered-Date: 11FEB2000
Description: This is the Linux System V init.
                The source package has the debian build files included.
                This version can be compiled with glibc 2.0.6 and up.
Author: miquels@cistron.nl (Miquel van Smoorenburg)
Primary-Site: sunsite.unc.edu /pub/Linux/system/daemons/init
                109K sysvinit-2.78.tar.gz
Alternate-Site: ftp.cistron.nl /pub/people/miquels/software
                109K sysvinit-2.78.tar.gz
Alternate-Site: ftp.debian.org /debian/dists/potato/main/source/base
                108K sysvinit_2.78-X.tar.gz
Copying-Policy: GPL
Keywords: init shutdown halt reboot
End


ftp.debian.org:/debian/dists/potato/main/source/base/sysvinit_2.78-2.tar.gz

https://build.opensuse.org/package/files?package=sysvinit&project=YaST%3AWeb

Some properties:

#define VT_MASTER "/dev/tty0"         /* Virtual console master */
#define CONSOLE "/dev/console"     /* Logical system console */
#define SECURETTY "/etc/securetty"     /* List of root terminals */
#define SDALLOW "/etc/shutdown.allow" /* Users allowed to shutdown */
#define INITTAB "/etc/inittab"     /* Location of inittab */
#define INIT "/sbin/init"     /* Location of init itself. */
#define NOLOGIN "/etc/nologin"     /* Stop user logging in. */
#define FASTBOOT "/fastboot"         /* Enable fast boot. */
#define FORCEFSCK "/forcefsck"     /* Force fsck on boot */
#define SDPID "/var/run/shutdown.pid" /* PID of shutdown program */
#define SHELL "/bin/sh"         /* Default shell */
#define SULOGIN "/sbin/sulogin"     /* Sulogin */
#define INITSCRIPT "/etc/initscript"     /* Initscript. */
#define PWRSTAT_OLD "/etc/powerstatus"     /* COMPAT: SIGPWR reason (OK/BAD) */
#define PWRSTAT "/var/run/powerstatus" /* COMPAT: SIGPWR reason (OK/BAD) */

#if 0
#define INITLVL "/etc/initrunlvl"     /* COMPAT: New runlevel */
#define INITLVL2 "/var/log/initrunlvl" /* COMPAT: New runlevel */
                            /* Note: INITLVL2 definition needs INITLVL */
#define HALTSCRIPT1 "/etc/init.d/halt"     /* Called by "fast" shutdown */
#define HALTSCRIPT2 "/etc/rc.d/rc.0"     /* Called by "fast" shutdown */
#define REBOOTSCRIPT1 "/etc/init.d/reboot" /* Ditto. */
#define REBOOTSCRIPT2 "/etc/rc.d/rc.6" /* Ditto. */



- It exits if UID is != 0 (root)
- It exits if PID != 1 (the first process in Kernel's userspace)
- It check command-line args:
    "single", "-s"      : dfl_level is set to 'S'
    "-a", "auto"        : set environment "AUTOBOOT=YES"
    "-b", "emergency"   : emerg_shell = 1
    "-z"                : ignore -z xxxx
    any of [0-9],[sS]   : dfl_level is set accordingly to that level

- set default environment PATH to "/sbin:/usr/sbin:/bin:/usr/bin"
- say "@(#) init version 2.89  DATE 26-Mar-2010  miquels@cistron.nl booting" into syslog
- spawn/fork to emergency shell if emerg_shell == 1
- read inittab and configure setting based on the settings stored in INITTAB

init.c: main() ---> setproctitle()
    |
    |
    V
init_main() ----------------------------> read_inittab()
 |  |   |
 |  |   |
 |  |   V
 |  |   init_reboot(BMAGIC_SOFT)
 |  |
 |  |
 |  V
 | ioctl(f, KDSIGACCEPT, SIGWINCH): tell kernel SIGACCEPT
 |
 +---> set a bunch of signals' flags
 |
 +----> console_init(), open /dev/CONSOLE (or otherwise if specified in env "CONSOLE") for O_RDONLY
 |
 +----> console_stty() : Set terminal settings to reasonable defaults
 |
 +----> set default environment PATH to "/sbin:/usr/sbin:/bin:/usr/bin"
 |
 loop forever by doing this stuf:
    1) boot transitions
    2) Read from the init FIFO by calling check_init_fifo():
        2.1) try to create /dev/initctl if not present.
        2.2) If /dev/initctl is open, stat the file to see if it is still the _same_ inode
        2.3) try to open /dev/initctl
        2.4) Read data from the pipe, return on EINTR
        2.5) console_init
        2.6) process requests (e.g., runlevel change request, power fail request, set env)

    3) check the 'failing' flags
    4) process any signal:
        4.1) SIGPWR event/signal
        4.2) SIGINT
        4.3) SIGWINCH
        4.4) SIGALRM
        4.5) SIGCHLD
        4.6) SIGHUP
    5) See whether we need to start up (again)




BOOT TRANSITION FSM
--------------------



        '#' (SYSINIT) --+-----> '*' (BOOT) ------> (NORMAL)
                        |              ^
                        |              |
           newlevel=='S'|              | !did_boot && newlevel != 'S'
                        |              |
                        +-----> 'S' (INIT)
                                       ^
                                       |
                                       |
                                   start here