Re: tlug: *kernel hacking* question (sort of)

[Chris Sekiya <chris@example.com>]

On Tue, 1 Dec 1998, Scott Stone wrote:

> I have a hard time believing that it works on neither the ATAPI driver nor
> the SCSI CDROM driver... tried it on both...

It may really not be implemented.  PTRACE_GETFPREGS existed as a header
define for a *long* time, but it didn't actually work until a couple of
months ago (that's why gdb doesn't let you peek at FP registers, by the
way).

Well, when in doubt pull out the kernel source.  I see two ioctls that
might be candidates, around line 385:

        case CDROM_DRIVE_STATUS:
                if (cdo->drive_status == NULL)
                        return -EINVAL;
                else
                        return cdo->drive_status(dev);

        case CDROM_DISC_STATUS:
                if (cdo->disc_status == NULL)
                        return -EINVAL;
                else
                        return cdo->disc_status(dev);

... should be pretty obvious what's going on there.

Ah, wait ... 2.0 kernels doesn't use the unified cdrom driver.  So, yeah,
it doesn't surprise me that neither the ATAPI nor the SCSI driver don't
seem to implement either function ...


-- Chris



----------------------------------------------------------------
Next Technical Meeting: 12 December, 12:30 *** place TBA ***
IMPORTANT: TLUG is looking for a venue for the next meeting
if you could host in your university or office, please contact us
Next Nomikai: 15 January 1999, 19:30 Tengu TokyoEkiMae 03-3275-3691
----------------------------------------------------------------
more info: http://tlug.linux.or.jp Sponsors: PHT, HSBC Securities