Hi All:
I want to move two local valuables to x86 arch CPU ebx, ecx
register and do outb cpu instruction by using AT&A inline asm in
kernel driver. The following code was I wrote but gcc report syntax
error:
==
unsigned int val = 10;
unsigned int tmp = 5;
....
__asm__ volatile ("movl %0, %%ebx"
"movl %1, %%ecx"
"outb $0x27, $0xb2"
:
:"r"(val), "r"(tmp)
:"%ebx", "%ecx"
);
Does anyone can point me out. Any reply is appreciated.
BRs, H. Johnny
How about putting \n at the end ?
Just try out,
__asm__ volatile ("movl %0, %%ebx\n"
"movl %1, %%ecx\n"
Thanks,
Viral Mehta,
Embedded Software Engineer,
Tel. No. 91 79 26563705, Ext. 423
http://www.einfochips.com <http://www.einfochips.com>
Prepare and Prevent rather than Repair and Repent
Johnny Hung wrote:
> Hi All:
> I want to move two local valuables to x86 arch CPU ebx, ecx
> register and do outb cpu instruction by using AT&A inline asm in
> kernel driver. The following code was I wrote but gcc report syntax
> error:
> ==
> unsigned int val = 10;
> unsigned int tmp = 5;
> ....
> __asm__ volatile ("movl %0, %%ebx"
> "movl %1, %%ecx"
> "outb $0x27, $0xb2"
> :
> :"r"(val), "r"(tmp)
> :"%ebx", "%ecx"
> );
>
> Does anyone can point me out. Any reply is appreciated.
>
> BRs, H. Johnny
>
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It doesn't works. :(
2009/11/19 Viral Mehta <[email protected]>:
> How about putting \n at the end ?
>
> Just try out,
>
> __asm__ volatile ("movl %0, %%ebx\n"
> ? ? ? ? "movl %1, %%ecx\n"
>
>
>
>
> Thanks,
> Viral Mehta,
> Embedded Software Engineer,
> Tel. No. 91 79 26563705, Ext. 423
> http://www.einfochips.com <http://www.einfochips.com>
> Prepare and Prevent rather than Repair and Repent
>
>
> Johnny Hung wrote:
>>
>> Hi All:
>> ? ?I want to move two local valuables to x86 arch CPU ebx, ecx
>> register and do outb cpu instruction by using AT&A inline asm in
>> kernel driver. ?The following code was I wrote but gcc report syntax
>> error:
>> ==
>> ? ?unsigned int val = 10;
>> ? ?unsigned int tmp = 5;
>> ? ?....
>> ? ?__asm__ volatile ("movl %0, %%ebx"
>> ? ? ? ? ?"movl %1, %%ecx"
>> ? ? ? ? ?"outb $0x27, $0xb2"
>> ? ? ? ? ?:
>> ? ? ? ? ?:"r"(val), "r"(tmp)
>> ? ? ? ? ?:"%ebx", "%ecx"
>> ? );
>>
>> Does anyone can point me out. Any reply is appreciated.
>>
>> BRs, H. Johnny
>>
>> --
>> To unsubscribe from this list: send an email with
>> "unsubscribe kernelnewbies" to [email protected]
>> Please read the FAQ at http://kernelnewbies.org/FAQ
>>
>>
>>
>> Email Scanned for Virus & Dangerous Content by : http://www.CleanMailGateway.com
>>
>>
>>
>
> --
> _____________________________________________________________________
> Disclaimer: This e-mail message and all attachments transmitted with it
> are intended solely for the use of the addressee and may contain legally
> privileged and confidential information. If the reader of this message
> is not the intended recipient, or an employee or agent responsible for
> delivering this message to the intended recipient, you are hereby
> notified that any dissemination, distribution, copying, or other use of
> this message or its attachments is strictly prohibited. If you have
> received this message in error, please notify the sender immediately by
> replying to this message and please delete it from your computer. Any
> views expressed in this message are those of the individual sender
> unless otherwise stated.Company has taken enough precautions to prevent
> the spread of viruses. However the company accepts no liability for any
> damage caused by any virus transmitted by this email.
> _____________________________________________________________________
>
>
On Thu, Nov 19, 2009 at 5:50 PM, Johnny Hung <[email protected]> wrote:
> Hi All:
> I want to move two local valuables to x86 arch CPU ebx, ecx
> register and do outb cpu instruction by using AT&A inline asm in
> kernel driver. The following code was I wrote but gcc report syntax
> error:
You must mean AT&T.
> ==
> unsigned int val = 10;
> unsigned int tmp = 5;
> ....
> __asm__ volatile ("movl %0, %%ebx"
You need to put "\n\t" in the end of each asm statement.
> "movl %1, %%ecx"
> "outb $0x27, $0xb2"
This is wrong, 'outb' instruction cann't accept both of
its operands as constants, IIRC.
> :
> :"r"(val), "r"(tmp)
> :"%ebx", "%ecx"
> );
>
> Does anyone can point me out. Any reply is appreciated.
Regards.
On 11/19/2009 10:50 AM, Johnny Hung wrote:
> Hi All:
> I want to move two local valuables to x86 arch CPU ebx, ecx
> register and do outb cpu instruction by using AT&A inline asm in
> kernel driver. The following code was I wrote but gcc report syntax
> error:
> ==
> unsigned int val = 10;
> unsigned int tmp = 5;
> ....
> __asm__ volatile ("movl %0, %%ebx"
> "movl %1, %%ecx"
> "outb $0x27, $0xb2"
> :
> :"r"(val), "r"(tmp)
> :"%ebx", "%ecx"
> );
>
> Does anyone can point me out. Any reply is appreciated.
Why not just:
("outb $0x27, %%al" : : "a" (0xb2), "b"(val), "c" (tmp));
--
js
Faculty of Informatics, Masaryk University
Suse Labs, Novell
After testing:
# gcc inlineasm.c
inlineasm.c: Assembler messages:
inlineasm.c:7: Error: suffix or operands invalid for `out'
[root@debian-johnny] ~/workspace/test
# cat inlineasm.c
#include <stdio.h>
int main ()
{
unsigned int val = 5, tmp = 10;
asm volatile ("outb $0x27, %%al"
:
: "a" (0xb2), "b"(val), "c" (tmp)
);
}
It seems the source of outb instruction cannot be a constant. Is
there a AT&T instructions document for x86?
BRs, H. Johnny
> Why not just:
> ("outb $0x27, %%al" : : "a" (0xb2), "b"(val), "c" (tmp));
> --
> js
> Faculty of Informatics, Masaryk University
> Suse Labs, Novell
>
On Sun, Nov 22, 2009 at 10:14 PM, Johnny Hung <[email protected]> wrote:
> After testing:
>
> # gcc inlineasm.c
> inlineasm.c: Assembler messages:
> inlineasm.c:7: Error: suffix or operands invalid for `out'
> [root@debian-johnny] ~/workspace/test
>
> # cat inlineasm.c
> #include <stdio.h>
>
> int main ()
> {
> unsigned int val = 5, tmp = 10;
> asm volatile ("outb $0x27, %%al"
> :
> : "a" (0xb2), "b"(val), "c" (tmp)
> );
> }
>
> It seems the source of outb instruction cannot be a constant. Is
> there a AT&T instructions document for x86?
In AT&T syntax, the source register comes first. So it should be
"outb %%al, $0x27", assuming that 0x27 is the port number you are
trying to write to.
--
Brian Gerst