Microport shmcreate

Microport shmcreate

Post by r.. » Wed, 02 May 1990 23:44:00



This line == can of raid.

        Greetings. I have a problem with the shmcreate facility of
Microport Unix 2.2 when attempting to use shared memory to access
the Hercules bit mapped graphics memory. The documentation says to
put the following line in /etc/rc:

        /etc/shmcreate 0xb0000 b0000 32768  /* create a segment whose key is
                                            b0000, mapped to physical address
                                            b0000, with length 32768 bytes. */

        In the user program, the following code should give me access
to the  shared memory through char * pointer shmaddr:

        extern char *shmat();

        shmid = shmget (0xb8000,32768,0);   /* shmid is an int, large model */

        shmaddr = shmat (shmid, (char *) 0); /* shmaddr is a large model pntr */

        However, in all cases, shmget returns -1 and errno gets set to

ENOENT. What am I doing wrong? I am remembering to compile using
the large model.
        Any help would be appreciated. Send to me, and I will post summary
to the net. This is my first post ever, if there are mistakes, polite flames
only.

Robert White, Graphics Information Inc.
UUCP: seismo!nbires!hao!scicom!qetzal!rcw

*************
* what are  *
* these box *
* logos     *
* anyway?   *
*************
he    

 
 
 

Microport shmcreate

Post by John Ploch » Wed, 02 May 1990 08:33:00


This is a topic which has broad interest (there are lots of Microport users
out there) so I am posting this instead of mailing.  I'm glad to see that
I'm not the only one having problems with this!


|
|       Greetings. I have a problem with the shmcreate facility of
| Microport Unix 2.2 when attempting to use shared memory to access
| the Hercules bit mapped graphics memory.
|
|       extern char *shmat();
|       shmid = shmget (0xb8000,32768,0);   /* shmid is an int, large model */

Problem 1:
        shmid = shmget ((key_t)0xb8000,32768,0);
                        ^^^^^^^  the key parameter is not an int, but a long

|       shmaddr = shmat (shmid, (char *) 0); /* shmaddr is a large model pntr */

Problem 2:
        shmaddr = shmat (shmid, (char *) 0, 0);
                                          ^^^  Bug in MicroPort manual, need
                                               a flag here to tell shmat to
                                               give read/write permission to
                                               this memory.
|
|       However, in all cases, shmget returns -1 and errno gets set to
| ENOENT. What am I doing wrong?
|
| Robert White, Graphics Information Inc.
+----

Problem 3:
        The Microport SV/AT release 2.2 (and before) version of shmcreate
        is BROKEN.  It doesn't attach the segment created to the proper
        physical memory location.  I got bit by this last week...  No
        work-around,  call tech support and bug them about getting a fix
        to this program.

--
 John Plocher           UUCP: <backbone>!uwvax!uwmacc!hobbes!plocher



 
 
 

Microport shmcreate

Post by Josh Sieg » Wed, 02 May 1990 17:05:00



>This line == can of raid.

>    Greetings. I have a problem with the shmcreate facility of
>Microport Unix 2.2 when attempting to use shared memory to access
>the Hercules bit mapped graphics memory. The documentation says to
>put the following line in /etc/rc:

>    /etc/shmcreate 0xb0000 b0000 32768  /* create a segment whose key is
>                                        b0000, mapped to physical address
>                                        b0000, with length 32768 bytes. */

>    In the user program, the following code should give me access
>to the  shared memory through char * pointer shmaddr:

>    extern char *shmat();

>    shmid = shmget (0xb8000,32768,0);   /* shmid is an int, large model */

>    shmaddr = shmat (shmid, (char *) 0); /* shmaddr is a large model pntr */

All together now...

        If ya going to include examples... make sure the examples
        are bug free!

Your making a key of b0000 and asking for a key of b8000.

Is this a typo?

                        --Josh Siegel
--

        It's a 9mm hand gun... useful for killing people...
                If you're into that sorta thing...

 
 
 

Microport shmcreate

Post by sy.. » Wed, 02 May 1990 21:47:00


This line == can of raid.

        Greetings. I have a problem with the shmcreate facility of
Microport Unix 2.2 when attempting to use shared memory to access
the Hercules bit mapped graphics memory. The documentation says to
put the following line in /etc/rc:

        /etc/shmcreate 0xb0000 b0000 32768  /* create a segment whose key is
                                            b0000, mapped to physical address
                                            b0000, with length 32768 bytes. */

        In the user program, the following code should give me access
to the  shared memory through char * pointer shmaddr:

        extern char *shmat();

        shmid = shmget (0xb8000,32768,0);   /* shmid is an int, large model */

        shmaddr = shmat (shmid, (char *) 0); /* shmaddr is a large model pntr */

        However, in all cases, shmget returns -1 and errno gets set to

ENOENT. What am I doing wrong? I am remembering to compile using
the large model.
        Any help would be appreciated. Send to me, and I will post summary
to the net. This is my first post ever, if there are mistakes, polite flames
only.

Robert White, Graphics Information Inc.
UUCP: seismo!nbires!hao!scicom!qetzal!rcw

*************
* what are  *
* these box *
* logos     *
* anyway?   *
*************

 
 
 

1. SVGA driver needed for Microport Unix. HELP.

Our client has about 400 Goldstar Pcs running Microport Unix System
5 Release 3.2 and X-Windows X11R3.  Each PC has a Pastel 1024 Super
VGA card (C & B Technologies CO. LTD) capable of displaying 256
colors in 640x480 resolution.  The Pastel board uses a Tseng 3000AX
chipset.  The Unix device driver for the Pastel only supports 16
colors in 640x480 resolution.  I need to come up with a driver that
supports all 256 colors.  I am open to any leads or advice.  I am
looking for any of the following:

o    A device driver written for Microport Unix and the Tseng
     3000AX

o    Source code for a driver for the Tseng 3000AX written for any
     Unix system

o    An individual or company willing to write a Unix SVGA driver
     from scratch or modify a similar one they have already
     written.  Naturally the individual or company would have to
     demonstrate experience in writing Unix device drivers and
     familiarity with programming SVGA chips.

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