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[ts-7000] Re: 7260 mmap of /dev/mem fails strerror No Such Device - Help

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Subject: [ts-7000] Re: 7260 mmap of /dev/mem fails strerror No Such Device - Help
From: "xioaya12" <>
Date: Sun, 16 Apr 2006 22:21:22 -0000
Much thanks !!
Sometimes I can stare at the code for a while
before I see those. Funny how the compiler does
what we tell it rather than what we mean.

at 0x0020 I saw the light.

Now I can have some real fun.

Best regards,

Rich

--- In  "Phil" <> wrote:
>
> Hi,
> 
> From looking at your program, I would say that your problem is just
> a small parentheses position issue. The line ...
> 
> >  if((fd = open("/dev/mem", O_RDWR | O_SYNC) == -1)) {
> 
> should look more like
> 
> >  if((fd = open("/dev/mem", O_RDWR | O_SYNC)) == -1) {
> 
> 
> Your 'fd' was getting assigned the result of the comparison not the
> actual file descriptor.
> 
> Hope this is all it is. Let us know.
> 
> Cheers
> Phil
> 
> 
> --- In  "xioaya12" <xioaya12@> wrote:
> >
> > Just received my 7260 with Dev USB Drive w/ Debian
> > Booted TS-Linux OK
> > /usr/bin/loadUSBModules.sh
> > /usr/bin/loadUSB.sh
> > Booted Debian on USB drive OK
> > vim'd testlight.c as root (see below)
> > failed on the return to mmap after success on open /dev/mem
> > strerror set to No Such Device, and file descriptor was 0 ???
> > expected > 2
> > 
> > I'm new to Linux and probably missed something simple.
> >  
> > (mknod ???, gcc -???, someother ???.sh, chmod ???)
> > mmap is byte aligned to the correct 7260 address. 
> > 
> > Details are below, code, ps, perms on /dev:(Thanks in advance)
> > 
> > ts7200:~# whoami
> > root
> > ts7200:~# cd /usr/rich
> > ts7200:/usr/rich# cat testlight.c
> > #include<stdio.h>
> > #include<unistd.h>
> > #include<errno.h>
> > #include<sys/types.h>
> > #include<sys/mman.h>
> > #include<sys/time.h>
> > #include<fcntl.h>
> > #include<string.h>
> > #define BASE_ADDRESS  0x80840000
> > #define DIAG_LED_OFFSET  0x020
> > extern int errno;
> > 
> > int main(int argc, char **argv) {
> >     int fd;
> >     unsigned char *start;
> >     volatile  unsigned int *dat;
> >     int i, psize;
> > 
> >     if((fd = open("/dev/mem", O_RDWR | O_SYNC) == -1)) {
> >       printf("Cannot open /dev/mem\n"); 
> >       exit(-1);
> >     }
> >     psize = getpagesize();
> >     if((start = (unsigned char*) mmap(0, psize, 
> >                             PROT_READ | PROT_WRITE, 
> >                             MAP_SHARED, fd, 
> >                             BASE_ADDRESS)) == MAP_FAILED) {
> >       printf("Cannot map /dev/mem ret=%d ps=%d fd=%d\n", 
> >                   start, psize, fd);
> >       printf("Why: %s\n",strerror(errno));
> >       close(fd); 
> >           exit(-1);
> >     }
> >     close(fd);
> >     exit(0);
> > }
> >     
> > ts7200:/usr/rich# gcc -o testlight testlight.c
> > ts7200:/usr/rich# ls -l
> > total 7
> > -rwxr-xr-x    1 root     root         5692 Apr 15 21:04 testlight
> > -rw-r--r--    1 root     root          975 Apr 15 19:27 
testlight.c
> > ts7200:/usr/rich# ./testlight
> > Cannot map /dev/mem ret=-1 ps=4096 fd=0
> > Why: No such device
> > 
> > ts7200:/usr/rich#ls -l /dev/mem /dev/kmem
> > crw-r-----    1 root     kmem       1,   2 Dec 31  1969 /dev/kmem
> > crw-r-----    1 root     kmem       1,   1 Dec 31  1969 /dev/mem
> > 
> > some other devices, updated today but not /dev/mem ???
> > 
> > lr-xr-xr-x    1 root     root            4 Apr 15 21:00 ram0 -> 
> rd/0
> > lr-xr-xr-x    1 root     root            4 Apr 15 21:00 ram1 -> 
> rd/1
> > 
> > lr-xr-xr-x    1 root     root           33 Apr 15 21:00 sda -> 
> > scsi/host0/bus0/target0/lun0/disc
> > lr-xr-xr-x    1 root     root           34 Apr 15 21:00 sda1 -> 
> > scsi/host0/bus0/target0/lun0/part1
> > lr-xr-xr-x    1 root     root            4 Dec 31  1969 stderr -
> 
> > fd/2
> > lr-xr-xr-x    1 root     root            4 Dec 31  1969 stdin -> 
> fd/0
> > lr-xr-xr-x    1 root     root            4 Dec 31  1969 stdout -
> 
> > fd/1
> > crw-rw-rw-    1 root     tty        5,   0 Dec 31  1969 tty
> > lr-xr-xr-x    1 root     root            4 Apr 15 21:00 tty0 -> 
> vc/0
> > 
> > crw-------    1 root     root     204,  16 Apr 15 21:05 ttyAM0
> > crw--w--w-    1 root     root     204,  17 Apr 15 20:58 ttyAM1
> > 
> > ps aux
> > USER       PID %CPU %MEM   VSZ  RSS TTY      STAT START   TIME 
> > COMMAND
> > root         1  0.6  0.7  1432  468 ?        S    20:58   0:01 
> init 
> > [3]  
> > root         2  0.0  0.0     0    0 ?        SW   20:58   0:00 
> > [keventd]
> > root         3  0.2  0.0     0    0 ?        RWN  20:58   0:00 
> > [ksoftirqd_CPU0]
> > root         4  0.0  0.0     0    0 ?        SW   20:58   0:00 
> > [kswapd]
> > root         5  0.0  0.0     0    0 ?        SW   20:58   0:00 
> > [bdflush]
> > root         6  0.0  0.0     0    0 ?        SW   20:58   0:00 
> > [kupdated]
> > root         7  0.0  0.0     0    0 ?        SW   20:58   0:00 
> > [mtdblockd]
> > daemon      54  0.0  0.7  1628  456 ?        S    20:58   
> > 0:00 /sbin/portmap
> > root        59  0.0  1.1  3768  676 ?        S    20:58   
> > 0:00 /usr/sbin/inetd
> > root        64  0.0  0.6  3432  412 ?        S    20:58   
> > 0:00 /usr/sbin/telnetd
> > root        73  0.0  1.7  3088 1080 ?        S    20:58   
> > 0:00 /www/apache/bin/h
> > #200        78  0.0  1.7  3088 1068 ?        S    20:58   
> > 0:00 /www/apache/bin/h
> > #200        79  0.0  1.7  3088 1068 ?        S    20:58   
> > 0:00 /www/apache/bin/h
> > #200        80  0.0  1.7  3088 1068 ?        S    20:58   
> > 0:00 /www/apache/bin/h
> > #200        81  0.0  1.7  3088 1068 ?        S    20:58   
> > 0:00 /www/apache/bin/h
> > #200        82  0.0  1.7  3088 1068 ?        S    20:58   
> > 0:00 /www/apache/bin/h
> > root        89  0.0  1.0  3568  648 ?        S    20:58   0:00 -
sh
> > root        90  0.0  0.8  3564  536 ?        S    20:58   
> > 0:00 /sbin/getty -L 11
> > root        93  0.0  0.0     0    0 ?        SW   20:59   0:00 
> > [khubd]
> > root       101  0.5  0.0     0    0 ?        SW   20:59   0:01 
> [usb-
> > storage-0]
> > root       102  0.0  0.0     0    0 ?        SW   20:59   0:00 
> > [scsi_eh_0]
> > root       104  0.0  0.8  3560  536 ?        S    21:00   
> > 0:00 /bin/sh /usr/bin/
> > root       107  0.0  1.5  2240  968 ttyAM0   S    21:00   
> > 0:00 /bin/sh /etc/init
> > root       122  0.0  1.2  1672  780 ?        S    21:00   
> > 0:00 /sbin/devfsd /dev
> > root       272  0.0  1.3  2380  832 ?        S    21:01   
> > 0:00 /sbin/syslogd
> > root       334  0.0  0.9  1432  588 ?        S    21:01   
> > 0:00 /sbin/klogd
> > root       338  0.0  1.2  1608  744 ?        S    21:01   
> > 0:00 /sbin/rpc.statd
> > root       343  0.0  1.3  2380  808 ?        S    21:01   
> > 0:00 /usr/sbin/inetd
> > root       363  0.0  1.2  1872  740 ?        S    21:01   
> > 0:00 /usr/sbin/cron
> > root       370  0.0  2.1  2484 1288 ttyAM0   S    21:01   0:00 
bash
> > root       371  0.0  1.4  2832  900 ttyAM0   R    21:03   0:00 
ps -
> > aux
> >
>






 
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