Re: [Etherboot-developers] [COMMIT] 5.1.2+ boot from disk.

[<ebi...@ln...>]

ebi...@ln... (Eric W. Biederman) writes:

> ke...@us... (Ken Yap) writes:
> 
> > >I got a bit further than you. I'm using a 3c509.  I got my Etherboot ROM
> > >to load another ROM image and that worked, the 5.1.2rc3 image started
> > >executing, and prompted me for N or L. I chose N and it said Probing
> > >pci, no BIOS32\n Probing isa...[3c5x9] blah blah, and then froze after
> > >printing the MAC address.
> > 
> > Oh and the 3 second timeout didn't work so the PCBIOS timer is probably
> > not working. That may be the same reason for the freeze actually.
> 
> Hmm?  3 second timeout.

Eric the ASK_BOOT=3 timeout.   I usually set it to 1, and forgot
the default was 3.  So the BIOS based currticks is running at the
wrong speed, interesting.  Given that you chose N I assume it was
running slow? 

O.k.  A slow timer would certain give a freeze.

Sounds like I made a small bug in pcbios.S

Looking at the code....

O.k.  The BIOS based currticks is definitely bugging in the
presence of relocation.  The absolute BIOS addresses are not
fixed up, so if any amount of relocation is applied the will
read the wrong address.

Please, Please, Please when testing the new etherboot tell me if
what image you are testing.  And if you can test the non relocated
case.  I suspect there will be a bazillion little bugs when etherboot
is running relocated that is going to take a while to track down.

That is the big hunt before 5.2.

Anyway I believe the untested patch below should fix the timer
problem.

Eric


/**************************************************************************
CURRTICKS - Get Time
Use direct memory access to BIOS variables, longword 0040:006C (ticks
today) and byte 0040:0070 (midnight crossover flag) instead of calling
timeofday BIOS interrupt.
**************************************************************************/
	.globl	currticks
currticks:
	pushl	%ebp
	pushl	%ebx
	pushl	%esi
	pushl	%edi
#ifdef FREEBSD_PXEEMU
	cmpb	$0, pxeemu_nbp_active
	jne	currticks_postswitch
#endif

	pushl	$ 10f
	pushl	$ 20f - 10f
	call	_real_call
	.section ".text16"
10:	.code16
	ret
20:	.code32
	.previous

#ifdef FREEBSD_PXEEMU
currticks_postswitch:
#endif
-	movl	0x46C, %eax
-	movb	0x470, %bl
+       movl    virt_offset, %ebp
+       negl	%ebp			/* Physical address 0 */
+	movl    0x46C(%ebp), %eax
+	movb    0x470(%ebp), %bl
	cmpb	$0, %bl
	je	notmidnite
-	movb	$0, 0x470		/* clear the flag */
+	movb    $0, 0x470(%ebp)		/* clear the flag */
	addl	$0x1800b0,days		/* 0x1800b0 ticks per day */
notmidnite:
	addl	days,%eax
	popl	%edi
	popl	%esi
	popl	%ebx
	popl	%ebp
	ret