Having serious booting problems...

HELP! I am getting "panic: cannot open disk, 0x0/0x300, error 6".

Questions:
What is error 6 and which subroutine returns it? Look at dk_mountroot C functiion below.

I can't even determine the function doing the open, is it d_open()? It appears to be a field in a structure that contains a function pointer. We want to know what function it points to, during the boot phase. This function (somewhere in the kernel) is partially included below.

The function:

error = (cdevsw[major(rrootdev)].d_open)(rawdev, FREAD,

            S_IFCHR, curproc);

returns error 6. What is curproc? Appears to be a procedure, but can't seen to find what it is.

If so, where is the source for it? There's no man page. cdevsw seems to be a big table in RAM? How do I dump it? What does it contain? How do I trace this instruction?

Do you need help?

In addition to our free technical library, Pantek provides professional IT services to companies who utilize Open Source software: Learn more about Pantek's Technical Support offerings Place an order for 24/7/365 Technical Support here Learn more about Pantek, who we are, and what we do Chat with a Live Operator Related openbsd.org Links advocacy announce bugs ipv6 misc ports ports-changes security-announce smp source-changes tech Request more information about Pantek

How do I enter the kernel debugger from the command line? How do I exit it?
How do I save the "trace" and "ps" to a file to report? How can I do disk I/O from it (say, read sector #0?)

/* Snippet from kern/subr_disk.c: */

dk_mountroot()
{

	dev_t rawdev, rrootdev;
	int part = DISKPART(rootdev);
	int (*mountrootfn)(void);
	struct disklabel dl;
	int error;

	rrootdev = blktochr(rootdev);
	rawdev = MAKEDISKDEV(major(rrootdev), DISKUNIT(rootdev), RAW_PART);
	printf("rootdev=0x%x rrootdev=0x%x rawdev=0x%x\n", rootdev,
	    rrootdev, rawdev);

/* rootdev=0, rrootdev=0x300, rawdev=0x302 */


	error = (cdevsw[major(rrootdev)].d_open)(rawdev, FREAD,
	    S_IFCHR, curproc);
	if (error)
		panic("cannot open disk, 0x%x/0x%x, error %d",
		    rootdev, rrootdev, error);

Anyway - this is hard core stuff, but sometimes it takes digging at this level to try and find out why a system isn't booting. It apparently occurrs at the very earliest stage of the boot process.

Is there anyone out there that can answer these questions?

Regards
JD Received on Wed Nov 20 20:03:08 2002