Thanks, John.
Can I use the same source code for the driver developed for kernel 2.4 also in
2.6 ?
What about the makefile ?
As you can see, I have no experience about developing kernel modules.
Is there any good how-to or tutorial about writing Linux kernel modules,
especially for 2.6 ?
Best regards,
Giovanni
John Crispin <[EMAIL PROTECTED]> wrote: 2.6
modules always end in .ko so an insmod on a .o file will always
fail under 2.6
Quoting Giovanni <[EMAIL PROTECTED]>:
> It is passed a long time since the last time that I tried to compile
> the servo.c kernel module.
>
> Today, I restarted my activity on the Fox board and tried to compile
> the servo module.
>
> I succeeded with the compilation, but I failed when I tried to
> insert the module into the kernel of the Fox.
>
> I did the following:
>
> [EMAIL PROTECTED] /mnt/flash/root]1400# insmod servo.o
> Using servo.o
> insmod: cannot insert `servo.o': Invalid module format (-1): Exec
> format error
> [EMAIL PROTECTED] /mnt/flash/root]1400#
>
> As you see, I get and "Invalid module format" error.
>
> As you informed last time, in the source file I just commented out the lines
> > INC_MOD_USE_COUNT ;
>> and
>> DEC_MOD_USE_COUNT;
>
> I am using the 2.6 linux kernel. As far as I know the servo.c was
> developed as a kernel module for 2.4. Is that the problem ? If so,
> how can I make this kernel module for 2.6 ?
>
> In the attachment, you can see the files that I used.
>
> Best regards,
> Giovanni
>
> Ernst Mayerhofer <[EMAIL PROTECTED]> wrote:
> Sorry, I mean:
>
> MOD_INC_USE_COUNT;
> and
> MOD_DEC_USE_COUNT;
>
> of course. wish you a nice sunday.
>
> 2007/2/11, Ernst Mayerhofer <[EMAIL PROTECTED]>:
> >
> > I wrote the module for kernel 2.4.
> > if i understand this error messages correctly, just comment out the lines
> > INC_MOD_USE_COUNT ;
> > and
> > DEC_MOD_USE_COUNT;
> >
> > hopefully it will work now.
> >
> > greets,ernst
> >
> > 2007/2/11, Giovanni <[EMAIL PROTECTED]>:
> > >
> > > I tried to compile the servo.c program with the makefile indicated in
> > > the email, but I get a compilation error.
> > >
> > > Here is the Makefile:
> > >
> > > AXIS_TOP_DIR=/home/giovanni/fox/sdk/sdk-2.01-phrozen-new/devboard-R2_01
> > >
> > > TARGET := servo
> > > WARN := -W -Wstrict-prototypes -Wmissing-prototypes
> > > INCLUDE := -isystem /home/giovanni/fox/sdk/sdk-2.01-phrozen-new
> > > /devboard-R2_01/os/linux-2.6/include
> > > CFLAGS := -O2 -DMODULE -D__KERNEL__ ${WARN} ${INCLUDE} -mlinux -DCRISMMU
> > > CC := gcc-cris
> > >
> > > PREVENT_RECURSIVE_INCLUDE = 1
> > >
> > > PATH=$PATH:/usr/local/cris
> > >
> > > ${TARGET}.o: ${TARGET}.c
> > >
> > > .PHONY: clean
> > >
> > > clean:
> > > rm -rf {TARGET}.o
> > >
> > > Here is the error:
> > >
> > >
> [EMAIL PROTECTED]:~/fox/sdk/sdk-2.01-phrozen-new/devboard-R2_01/apps/servo$
> > > make
> > > gcc-cris -O2 -DMODULE -D__KERNEL__ -W -Wstrict-prototypes
> > > -Wmissing-prototypes -isystem /home/giovanni/fox/sdk/sdk-
> > > 2.01-phrozen-new/devboard-R2_01/os/linux-2.6/include -mlinux -DCRISMMU
> > > -c -o servo.o servo.c
> > > servo.c:29: warning: static declaration for `init_module' follows
> > > non-static
> > > servo.c:30: warning: static declaration for `cleanup_module' follows
> > > non-static
> > > servo.c: In function `device_open':
> > > servo.c:138: `MOD_INC_USE_COUNT' undeclared (first use in this function)
> > > servo.c:138: (Each undeclared identifier is reported only once
> > > servo.c:138: for each function it appears in.)
> > > servo.c: In function `device_release':
> > > servo.c:158: `MOD_DEC_USE_COUNT' undeclared (first use in this function)
> > > make: *** [servo.o] Error 1
> > >
> > > How can I do to make this file compile correctly ?
> > >
> > > Best regards,
> > > Giovanni
> > >
> > > Ernst Mayerhofer
> <[EMAIL PROTECTED]<ernst.mayerhofer%40gmail.com>>
> > > wrote: if you want to make something which works really well,
> you have to do
> > > it in
> > >
> > > the kernel ;-)
> > >
> > > I made a kernel module once. As I modified it now for you and didn't
> > > test it
> > > on the foxboard, there might be a problem, so feel free to ask me if
> > > there
> > > is some problem.
> > >
> > > just compile the servo.c attached with the also attached makefile. you
> > > have
> > > to change the path of AXIS_TOP_DIR in the Makefile.
> > >
> > > once you have compiled it, transfer it to the foxboard and type:
> > > $ insmod servo.o
> > > if you want to see the kernel log messages, type
> > > $ dmesg
> > > then you can make a new device node , eg
> > > $ mknod c /etc/servo c 249 0
> > > and, if you want to set the servo to a specific position, write the
> > > value of
> > > T_on in us to /etc/servo:
> > > $ echo 500 > /etc/servo
> > >
> > > it should work!
> > > notice that if you want to use it, you have to enable the fast timer
> > > api.
> > >
> > > greets and pardon for my bad english,
> > >
> > > ernst mayerhofer
> > >
> > > 2007/2/2, Giovanni <[EMAIL PROTECTED] <pino_otto%40yahoo.com>>:
> > > >
> > > > This solution sounds cool.
> > > >
> > > > Did you try it with a real case ?
> > > >
> > > > I would like to run some real working code based on this idea. If you
> > > have
> > > > some code ready to run, can you post it ? Otherwise we can collaborate
> > > to
> > > > develop some working code and test it.
> > > >
> > > > Best regards,
> > > > Giovanni
> > > >
> > > > spargelzack <[EMAIL PROTECTED]
> <spargelzack%40yahoo.com><spargelzack%40yahoo.com>>
> > > wrote:
> > > > (sorry if this shows up twice, i'm not familiar with the yahoo groups
> > > >
> > > > interface yet)
> > > >
> > > > Hi Everybody
> > > >
> > > > I found a cheap + fast solution for using servos with the foxboard.
> > > >
> > > > First, there is a way to use the i/o lines not described on the
> > > > acmesystems website (it's well known on the axis developer website
> > > > though). You can use write() on Ports A+B after proper initialization.
> > > >
> > > > The Clock interval is around 5 us, so you have to pass about 4000
> > > > values for a full 2ms period.
> > > >
> > > > But as i found out, the 20ms interval isn't all that important. What
> > > > matters is the length of the pulse.
> > > >
> > > > So, here's my code:
> > > >
> > > > --
> > > > #include <stdio.h>
> > > > #include "stdlib.h"
> > > > #include "unistd.h"
> > > > #include "sys/ioctl.h"
> > > > #include "fcntl.h"
> > > > #include <sys/time.h>
> > > > #include <asm/etraxgpio.h>
> > > >
> > > > int main(int argc, char **argv){
> > > > int fd;
> > > > int i;
> > > > int pos;
> > > > unsigned char mask;
> > > > unsigned char period[4000];
> > > >
> > > > if(argc > 1)
> > > > pos = atoi(argv[1]);
> > > > else
> > > > pos = 100;
> > > >
> > > > // better use memset() here, but this is proof-of-concept code
> > > > for(i=0; i<pos+1; i++){
> > > > if(pos > i)
> > > > period[i] = 0xFF;
> > > > else
> > > > period[i] = 0;
> > > > }
> > > >
> > > > fd = open("/dev/gpiob", O_RDWR);
> > > >
> > > > if(!fd){
> > > > printf("open error\n");
> > > > exit(-1);
> > > > }
> > > >
> > > > mask = 1<<6 | 1<<7; // use pins PB6 and PB7 according to the
> > > > fox pinout
> > > >
> > > > // prepare for write()
> > > > if(ioctl(fd, _IO(ETRAXGPIO_IOCTYPE, IO_CFG_WRITE_MODE),
> > > > IO_CFG_WRITE_MODE_VALUE(1, mask, 1<<1))){
> > > > perror("ioctl error");
> > > > exit(-1);
> > > > }
> > > >
> > > > for(;;){
> > > > write(fd, &period, pos+1); // write the pulse,
> > > > followed by a zero to set the output
> > > > usleep(5000); // let the CPU breathe a bit..
> > > > }
> > > > }
> > > > --
> > > >
> > > > This only works with ports A and B, not with the G line.
> > > >
> > > > Supply any value between 100 and 400 as first argument to set the
> > > > position of two servos connected to PB6 and PB7.
> > > >
> > > > example:
> > > >
> > > > ./motor 180
> > > >
> > > > This uses LESS THAN 1% CPU when running.
> > > >
> > > > This is proof of concept code, so it's UGLY AND NOT USEFUL OUT OF THE
> > > > BOX. Also, my english sucks a bit.
> > > >
> > > > --- In [email protected]
> <foxboard%40yahoogroups.com><foxboard%40yahoogroups.com>,
> > > "zooltheno1"
> > > > <[EMAIL PROTECTED]> wrote:
> > > > >
> > > > > Hi
> > > > > I want to use RC-Servos with the Foxboard, the normal interfall is
> > > > > 1-2ms and 20ms pause.
> > > > > I tried to use udelay for the delay, put the minimum is 40ms,
> > > > > which is far to slow, even normal AC is faster.
> > > > > How could I get the nesasery delay without 100% CPU load ?
> > > > >
> > > > > Bye
> > > > > Ralph
> > > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > ------------------------------------------------
> > > > Resources are limited, Imagination is unlimited.
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> > > >
> > > >
> > >
> > > [Non-text portions of this message have been removed]
> > >
> > >
> > >
> > >
> > >
> > > ------------------------------------------------
> > > Resources are limited, Imagination is unlimited.
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>
> [Non-text portions of this message have been removed]
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