LinuxQuestions.org - Error compiling C code

- Linux - General (https://www.linuxquestions.org/questions/linux-general-1/)

- - Error compiling C code (https://www.linuxquestions.org/questions/linux-general-1/error-compiling-c-code-762515/)

Isn't that why it uses this command to run the script?

sudo gcc -O2 -o rccar rccar.c

I don't know C/C++ so it's just a guess.

u got me there this time

"man outb" for me...

Hm,
According to the man page for my distribution ("man outb")

Quote:

The value argument is passed first and the port argument is passed second

And from what I can tell, that's exactly what rccar.c is doing;

Code:

sysop$ nl rccar.c|grep outb

    34  * *  outb(8, x)  = pin 5      UNUSED

    35  * *  outb(16, x)  = pin 6      Forward

    36  * *  outb(32, x)  = pin 7      Reverse

    37  * *  outb(64, x)  = pin 8      Left

    38  * *  outb(128, x) = pin 9      Right

    39  * *  outb(80, x)  = pin 6 & 8  FORWARDLEFT

    40  * *  outb(144, x) = pin 6 & 9  FORWARDRIGHT

    41  * *  outb(96, x)  = pin 7 & 8  REVERSELEFT

    42  * *  outb(160, x) = pin 7 & 9  REVERSERIGHT

    64  outb(16, LPT1PORT);    /* Set pin 9 to high */

    69  outb(32, LPT1PORT);

    74  outb(64, LPT1PORT);

    79  outb(128, LPT1PORT);

    84  outb(80, LPT1PORT);

    89  outb(144, LPT1PORT);

    94  outb(96, LPT1PORT);

    99  outb(160, LPT1PORT);

  105  outb(0, LPT1PORT);      /* Set the data signals (D0-7) of the port to all low (0) */

  110  outb(0, LPT1PORT);

However we have 9 "outb(#, x)" where I'm thinking we should be defining the port (LPT1PORT), rather than just "x"

I'm thinking that maybe one of the "outb" friends might help....

As for the optimization flags ("-O" versus "-O2" versus nothing), I think we're safe. The "outb" doesn't appear to be affected by those flags....

Quote:

Originally Posted by xeleema (Post 3722450)

Hm,
As for the optimization flags ("-O" versus "-O2" versus nothing), I think we're safe. The "outb" doesn't appear to be affected by those flags....

did you read my link?
@Original poster
try putting this on the top of the file
#define outb(n, port) outportb(port, n)
#define inpb inportb

Found more "outb" information....

Found an interesting chunk over here;

Quote:

Obsolete IO macros

Back in a time when AVR-GCC and avr-libc could not handle IO port access in the direct assignment form as they are handled now, all IO port access had to be done through specific macros that eventually resulted in inline assembly instructions performing the desired action.

These macros became obsolete, as reading and writing IO ports can be done by simply using the IO port name in an expression, and all bit manipulation (including those on IO ports) can be done using generic C bit manipulation operators.

The macros in this group simulate the historical behaviour. While they are supposed to be applied to IO ports, the emulation actually uses standard C methods, so they could be applied to arbitrary memory locations as well.
#define inp(port) (port)
#define outp(val, port) (port) = (val)
#define inb(port) (port)
#define outb(port, val) (port) = (val)
#define sbi(port, bit) (port) |= (1 << (bit))
#define cbi(port, bit) (port) &= ~(1 << (bit))

Quote:

Originally Posted by xeleema (Post 3722454)

Found an interesting chunk over here;

that obviously will not work

Got this after adding
#define outb(n, port) outportb(port, n)
#define inpb inport

[CODE]shawn@shawn-desktop:~/Desktop$ sudo gcc -O2 -o rccar rccar.c
[sudo] password for shawn:
rccar.c: In function ‘main’:
rccar.c:131: warning: ignoring return value of ‘read’, declared with attribute warn_unused_result
/tmp/ccuSNFAn.o: In function `main':
rccar.c:(.text+0x11e): undefined reference to `outportb'
rccar.c:(.text+0x150): undefined reference to `outportb'
rccar.c:(.text+0x180): undefined reference to `outportb'
rccar.c:(.text+0x1b0): undefined reference to `outportb'
rccar.c:(.text+0x1e0): undefined reference to `outportb'
/tmp/ccuSNFAn.o:rccar.c:(.text+0x210): more undefined references to `outportb' follow
collect2: ld returned 1 exit status
/CODE]

dang it!
this is one of those few reasons dos/windows is better then linux

FYI: swapping the port and value for all the "outb" statements didn't work.

Code:

sysop$ diff rccar.c rccar.c.new

64c64

< outb(LPT1PORT, 16);    /* Set pin 9 to high */

---

> outb(16, LPT1PORT);    /* Set pin 9 to high */

69c69

< outb(LPT1PORT, 32);

---

> outb(32, LPT1PORT);

74c74

< outb(LPT1PORT, 64);

---

> outb(64, LPT1PORT);

79c79

< outb(LPT1PORT, 128);

---

> outb(128, LPT1PORT);

84c84

< outb(LPT1PORT, 80);

---

> outb(80, LPT1PORT);

89c89

< outb(1LPT1PORT, 44);

---

> outb(144, LPT1PORT);

94c94

< outb(LPT1PORT, 96);

---

> outb(96, LPT1PORT);

99c99

< outb(LPT1PORT, 160);

---

> outb(160, LPT1PORT);

105c105

< outb(LPT1PORT, 0);      /* Set the data signals (D0-7) of the port to all low (0) */

---

> outb(0, LPT1PORT);      /* Set the data signals (D0-7) of the port to all low (0) */

"Teh Win" or "Fail" ?

Okay, get this, I added "#include <sys/io.h>

Code:

sysop$ gcc -O2 -o rccar rccar.c

sysop$ ldd rccar

        linux-gate.so.1 =>  (0xffffe000)

        libc.so.6 => /lib/libc.so.6 (0xb7f0a000)

        /lib/ld-linux.so.2 (0xb806b000)

sysop$ ./rccar

ioperm: Operation not permitted

*SO* close! I think we need to call i386_set_ioperm instead of just ioperm....

try compiling with gcc -O2 rccar rccar.c

When I added #include <sys/io.h>

I got this

Code:

shawn@shawn-desktop:~/Desktop$ sudo gcc -O2 -o rccar rccar.c

[sudo] password for shawn:

rccar.c:46:1: warning: "inpb" redefined

rccar.c:45:1: warning: this is the location of the previous definition

rccar.c: In function ?main?:

rccar.c:134: warning: ignoring return value of ?read?, declared with attribute warn_unused_result

I get this when I compile using

sudo gcc -O2 rccar rccar.c

as opposed to

sudo gcc -O2 -o rccar rccar.c

Code:

shawn@shawn-desktop:~/Desktop$ sudo gcc -O2 rccar rccar.c                                    

rccar.c:46:1: warning: "inpb" redefined                                                      

rccar.c:45:1: warning: this is the location of the previous definition

rccar.c: In function ‘main’:

rccar.c:134: warning: ignoring return value of ‘read’, declared with attribute warn_unused_result

rccar: In function `_start':

/build/buildd/glibc-2.9/csu/../sysdeps/i386/elf/start.S:65: multiple definition of `_start'

/usr/lib/gcc/i486-linux-gnu/4.3.3/../../../../lib/crt1.o:/build/buildd/glibc-2.9/csu/../sysdeps/i386/elf/start.S:65: first defined here

rccar:(.rodata+0x0): multiple definition of `_fp_hw'

/usr/lib/gcc/i486-linux-gnu/4.3.3/../../../../lib/crt1.o:(.rodata+0x0): first defined here

rccar: In function `_fini':

/build/buildd/glibc-2.9/csu/../sysdeps/generic/initfini.c:109: multiple definition of `_fini'

/usr/lib/gcc/i486-linux-gnu/4.3.3/../../../../lib/crti.o:/build/buildd/glibc-2.9/csu/../sysdeps/generic/initfini.c:109: first defined here

rccar:(.rodata+0x4): multiple definition of `_IO_stdin_used'

/usr/lib/gcc/i486-linux-gnu/4.3.3/../../../../lib/crt1.o:(.rodata.cst4+0x0): first defined here

rccar: In function `__data_start':

(.data+0x0): multiple definition of `__data_start'

/usr/lib/gcc/i486-linux-gnu/4.3.3/../../../../lib/crt1.o:(.data+0x0): first defined here

rccar: In function `__data_start':

(.data+0x4): multiple definition of `__dso_handle'

/usr/lib/gcc/i486-linux-gnu/4.3.3/crtbegin.o:(.data+0x0): first defined here

rccar: In function `_init':

/build/buildd/glibc-2.9/build-tree/i386-libc/csu/crti.S:15: multiple definition of `_init'

/usr/lib/gcc/i486-linux-gnu/4.3.3/../../../../lib/crti.o:/build/buildd/glibc-2.9/build-tree/i386-libc/csu/crti.S:15: first defined here

/tmp/cciBw3vh.o: In function `main':

rccar.c:(.text+0x0): multiple definition of `main'

rccar:(.text+0xc0): first defined here

/usr/lib/gcc/i486-linux-gnu/4.3.3/crtend.o:(.dtors+0x0): multiple definition of `__DTOR_END__'

rccar:(.dtors+0x4): first defined here

collect2: ld returned 1 exit status

Quote:

try compiling with gcc -O2 rccar rccar.c

Dropping the "-o" doesn't even work for me, I get

Quote:

root# gcc -O2 rccar rccar.c
gcc: rccar: No such file or directory