freenode/#mezzano - IRC Chatlog
Search
22:00:27
fitzsim
froggey: yes, I probably wasn't totally clear before; the screen fills up with IRQ 7, but other normal messages are interleaved within the mostly-IRQ-7 messages
22:01:59
fitzsim
so I thought I'd see what happened if I just suppressed the IRQ 7 message to focus on the other messages
22:03:26
froggey
I don't suppose you can easily flash the original firmware back on and boot with kboot? would be nice to compare
22:04:51
froggey
no, at this point I doubt it's a bootloader issue. there's something funny with the way hardware interrupts have been set up by the firmware
22:05:28
fitzsim
I did look for HPET references and didn't find anything about PIT emulation in the coreboot sources
22:10:06
froggey
I'd expect GRUB to rely on coreboot for all its device drivers, so it wouldn't have a /proc/interrupts equivalent
22:10:36
froggey
https://wiki.osdev.org/HPET#Interrupt_routing here's a basic description of how the HPET does PIT emulation, with respect to interrupts
22:13:37
froggey
so that kind of hints at there being a HPET or something similar doing PIT emulation
22:14:37
froggey
if all the IRQ7 messages start when the timer IRQ is unmasked, that kind of points to something being wrong with how the timer is connected to the PIT
22:14:52
froggey
like it's set for level triggered when it should be edged triggered, or something like that
22:16:47
froggey
fitzsim: does linux get booted through grub or is it loaded directly as a coreboot payload?
22:48:52
fitzsim
I just poked around some more; the GRUB command "lsacpi -2" does show an HPET entry
22:49:20
fitzsim
I think you'd be able to figure it out if I posted a video of cbmemc, which dumps lots and lots of messages from coreboot
23:20:11
fitzsim
froggey: it's still uploading: https://www.fitzsim.org/scratch/mezzano/cbmemc-1.mp4
23:21:06
fitzsim
the angle was sort of tricky, so the video is wobbly, but mplayer with '.' to do frame advance gives a clear snapshot of each page, at least for one or two frames
23:50:41
froggey
I think I'm going to have to put together some limited test case, but that'll have to wait
0:12:41
froggey
fitzsim: bit of a longshot, but can you try booting in qemu with the "-machine type=q35" option?
0:13:05
froggey
that makes qemu emulate a slightly more modern chipset, maybe it'll run into the same issue...
0:53:03
fitzsim
froggey: I think I tried q35 way back when I was first setting up my coreboot-on-QEMU setup