On Sunday 10 January 2010 21:02:16 Benjamin Herrenschmidt wrote: > On Sat, 2010-01-09 at 02:17 -0600, Rob Landley wrote: > > On Thursday 07 January 2010 21:00:43 Benjamin Herrenschmidt wrote: > > > > Ok, here's the fix. It's not the _right_ fix, but it Works For Me > > > > (tm) and I'll leave it to you guys to figure out what this _means_: > > > > > > I've failed to reproduce so far on both a Wallstreet powerbook (similar > > > generation and chipset as your beige G3) and a G5 with an added serial > > > port using current upstream... > > > > > > Can you verify it's still there ? I might be able to reproduce on a > > > Beige G3 as well next week. > > > > It's still there on qemu 0.11.0's "g3beige" emulation when you use > > CONFIG_SERIAL_PMACZILOG as the serial console. (QEMU 0.10.x used a 16550 > > serial chip for its g3beige emulation instead of the actual ZILOG one.) > > Still dunno if it's a qemu or bug or a kernel bug, I just know that > > kernel patch fixes it for me, and it comes back without the patch. > > > > I tested 2.6.32. Haven't tried the 2.6.32.3 but don't see why it would > > change this... > > Ok so I compiled qemu and things are a bit strange. > > How do you get the output of both channels of the serial port with it ? > > If I use -nographics, what happens is that OpenBIOS, for some reason, > tells qemu that the console on the second channel of the ESCC.
Instead of "-nographic", you could try "-serial stdio" instead? > I see my kernel messages in the console if I do console=ttyPZ0 but the > debug stuff goes where udbg initializes it, which is where OpenBIOS says > the FW console is, which is channel B and I don't know how to "see" that > with qemu. I'm just trying to get a serial console, which is why I'm booting the sucker with: qemu-system-ppc -M g3beige -nographic -no-reboot -kernel zImage-powerpc -hda image-powerpc.sqf -append "root=/dev/hda rw init=/usr/sbin/init.sh panic=1 PATH=/usr/bin console=ttyS0" I didn't even know there were more debug messages... I have CONFIG_SERIAL_PMACZILOG_TTYS=y of course: pmac_zilog: 0.6 (Benjamin Herrenschmidt <b...@kernel.crashing.org>) ttyS0 at MMIO 0x80813020 (irq = 16) is a Z85c30 ESCC - Serial port ttyS1 at MMIO 0x80813000 (irq = 17) is a Z85c30 ESCC - Serial port CONFIG_SERIO=y CONFIG_SERIAL_PMACZILOG=y CONFIG_SERIAL_PMACZILOG_TTYS=y CONFIG_SERIAL_PMACZILOG_CONSOLE=y > I do see it crash due to a message from the kernel but I can't get into > xmon which is a pain. Does the -serial stdio thing help? (I know to switch between screens in the qemu x11 window, it's ctrl-alt-number (so ctrl-alt-1, ctrl-alt-2, and so on. I really don't use 'em much, though.) > If I modify the kernel to force udbg on channel A (same channel as the > console), then the problem doesn't appear (it doesn't crash) :-) You can attach gdb to qemu via the "qemu -s" option and then in gdb use the "target remote" stuff like you would with gdbserver. It acts a bit like you've connected it to a jtag through openocd, if that helps... (I know qemu has many, many options I don't really use much.) > Cheers > Ben. Rob -- Latency is more important than throughput. It's that simple. - Linus Torvalds _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
