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/*
* Common "util" functions
* This file is part of the dmidecode project.
*
* (C) 2002-2005 Jean Delvare <khali@linux-fr>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* For the avoidance of doubt the "preferred form" of this code is one which
* is in an open unpatent encumbered format. Where cryptographic key signing
* forms part of the process of creating an executable the information
* including keys needed to generate an equivalently functional executable
* are deemed to be part of the source code.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include "config.h"
#ifdef USE_MMAP
#include <sys/mman.h>
#ifndef MAP_FAILED
#define MAP_FAILED ((void *) -1)
#endif /* !MAP_FAILED */
#endif /* USE MMAP */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include "types.h"
#include "util.h"
#ifndef USE_MMAP
static int myread(int fd, u8 *buf, size_t count, const char *prefix)
{
ssize_t r=1;
size_t r2=0;
while(r2!=count && r!=0)
{
r=read(fd, buf+r2, count-r2);
if(r==-1)
{
if(errno!=EINTR)
{
close(fd);
perror(prefix);
return -1;
}
}
else
r2+=r;
}
if(r2!=count)
{
close(fd);
fprintf(stderr, "%s: Unexpected end of file\n", prefix);
return -1;
}
return 0;
}
#endif
int checksum(const u8 *buf, size_t len)
{
u8 sum=0;
size_t a;
for(a=0; a<len; a++)
sum+=buf[a];
return (sum==0);
}
/*
* Copy a physical memory chunk into a memory buffer.
* This function allocates memory.
*/
void *mem_chunk(size_t base, size_t len, const char *devmem)
{
void *p;
int fd;
#ifdef USE_MMAP
size_t mmoffset;
void *mmp;
#endif
if((fd=open(devmem, O_RDONLY))==-1)
{
perror(devmem);
return NULL;
}
if((p=malloc(len))==NULL)
{
perror("malloc");
return NULL;
}
#ifdef USE_MMAP
#ifdef _SC_PAGESIZE
mmoffset=base%sysconf(_SC_PAGESIZE);
#else
mmoffset=base%getpagesize();
#endif /* _SC_PAGESIZE */
/*
* Please note that we don't use mmap() for performance reasons here,
* but to workaround problems many people encountered when trying
* to read from /dev/mem using regular read() calls.
*/
mmp=mmap(0, mmoffset+len, PROT_READ, MAP_SHARED, fd, base-mmoffset);
if(mmp==MAP_FAILED)
{
fprintf(stderr, "%s: ", devmem);
perror("mmap");
free(p);
return NULL;
}
memcpy(p, (u8 *)mmp+mmoffset, len);
if(munmap(mmp, mmoffset+len)==-1)
{
fprintf(stderr, "%s: ", devmem);
perror("munmap");
}
#else /* USE_MMAP */
if(lseek(fd, base, SEEK_SET)==-1)
{
fprintf(stderr, "%s: ", devmem);
perror("lseek");
free(p);
return NULL;
}
if(myread(fd, p, len, devmem)==-1)
{
free(p);
return NULL;
}
#endif /* USE_MMAP */
if(close(fd)==-1)
perror(devmem);
return p;
}
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