Re: [Qemu-devel] [RESEND] [PATCH] ide: fix GET_CONFIGURATION DVD-ROM support

[Carlo Marcelo Arenas Belon <carenas@sajinet.com.pe>]

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On Sat, Jan 05, 2008 at 10:28:34AM +0000, Stuart Brady wrote:
> On Fri, Jan 04, 2008 at 09:53:09PM -0600, Rob Landley wrote:
> > Except that according to http://en.wikipedia.org/wiki/CD-ROM it's actually 703 
> > and 1/8 binary megabytes (360,000 sectors *2048 bytes), which would be 
> > 1440000.
> 
> Apparently that value comes from 75 sectors per second * 80 minutes...
> 75*80*60 = 360000, and of course, 360000*2048/512 = 1440000, although
> it actually seems that it should be one sector less than 80 minutes, 
> which is 359999 2048-byte sectors or 1439996 512-byte chunks.
> 
> BTW, there are/were also 90 and 99 minute 'CD-Rs' -- Wikipedia's page on 
> CD-Rs describes them, but they were never very popular, and a lot of 
> drives can't read the discs.

the exact number of sectors is really not that relevant, as the whole point
here is to try to detect if it is a CD (700MB) or a DVD (4.7GB) and the logic
is just assuming that if it has more sectors than you should normally expect
in a CD, then it is a DVD.

attached the program I used in the guests (only works on Linux) to poke the 
emulated drive (or a physical drive if you feel like) and compare the responses
(you will need to take a look at the SPEC tables to interpret the data though)

for my own tests (using a linux guest with -cdrom /dev/cdrom in my linux
host that has a DVD-+RW drive) :

   700MB CD-R = 1374880 (with FreeSBIE 2.0.1)
  4.7GB DVD-R = 6939520 (with SXDE 9/07)

feel free to report back with the value to use then if you happen to have a CD
that is completely full but I had already enough problems trying to get this
merged without trying to change the code that much to try to guess a better
magic number than the one was originally used (I like 1440000 though)

Carlo

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/*
    ide-atapi

    Copyright (c) 2007 Carlo Marcelo Arenas Belon

    ide-atapi is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License version 2
    as published by the Free Software Foundation.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include <sys/ioctl.h>
#include <linux/cdrom.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>

int main (int argc, char *argv[])
{
   struct cdrom_generic_command cgc;
   struct request_sense sense;
   unsigned char buf[250];
   int i;

   if (argc < 2) {
      printf("Usage: %s <device>\n", argv[0]);
      printf("\n");
      printf("  device: where the commands are send\n");
      printf("\n");
      return 1;
   }

   memset (&cgc, 0, sizeof(struct cdrom_generic_command));
   memset (&sense, 0, sizeof(struct request_sense));
   memset (&buf, 0, sizeof(buf));

   int fd = open (argv[1], O_RDONLY | O_NONBLOCK);
   if (fd < 0) {
      printf("couldn't open device %s\n", argv[1]);
      return 1;
   }
   cgc.cmd[0] = GPCMD_GET_CONFIGURATION;
   cgc.cmd[1] = 0x00;
   cgc.cmd[8] = sizeof(buf);
   cgc.timeout = 100;
   cgc.buffer = buf;
   cgc.buflen = sizeof(buf);
   cgc.data_direction = CGC_DATA_READ;
   cgc.sense = &sense;
   cgc.quiet = 0;
   i = ioctl (fd, CDROM_SEND_PACKET, &cgc);
   if (i < 0) {
      printf("command failed\n");
      close (fd);
      return 1;
   }
   printf("Response raw dump:\n");
   for (i = 0; i<sizeof(buf); i++) {
      if (i % 16 == 0) printf("\n");
      printf("%02x ", buf[i]);
   }
   printf("\n");
   close (fd);
   return 0;
}