[syslinux] no display what can I try.

[Gene Cumm]

On Wed, Dec 20, 2017 at 10:37 PM, Locane <locane at gmail.com> wrote:
> Have you tried a different monitor?  Has that monitor ever shown you a boot
> loader menu?  It might be that it just doesn't support the low-level
> resolutions Grub is trying to use.

I can't say I've ever seen a monitor that didn't interpolate the very
low output sizes.

With that, have you tried other monitor ports?

> On Wed, Dec 20, 2017 at 7:09 PM, Jeff Sadowski via Syslinux
> <syslinux at zytor.com> wrote:
>>
>> I want to see things,  I'm not sure how quiet would work.

I was pointing out that you had "quiet" which would preclude you from
seeing anything from when you activated a menu option until well after
the Linux kernel has control.

>> Maybe next time I get the box I can re-put in the older working card
>> and try to do a firmware upgrade.
>> This does not seem distro specific. All versions of grub and syslinux
>> do not work in the default configs.

I misinterpreted your initial statement.  You really meant that after
the POST, there's no output until a higher graphics mode is enabled.
This is an almost pure hardware/firmware discussion.

Lots of things to check that you may or may not have examined.

 - Did you hook that monitor to another machine and see Syslinux/GRUB output?
 - Did you try plugging in monitors to some of the other outputs
including any possible onboard ports?
 - Is the machine actually a UEFI irmwware machine and you're using
the CSM for BIOS/legacy boot?
 - If UEFI, did you consider a UEFI boot?
 - Did you check on motherboard firmware updates?
 - Did you try without vesamenu.c32?
 - What output sizes did you try?
 - Regarding VESA modes that are reported, there may be a way with HDT
to automate the reporting to a TFTP server of the VESA modes the
system reports.

>> I will try using menu.c32 vs vesamenu.c32 as well. To see if it won't
>> display.
>>
>> On Wed, Dec 20, 2017 at 4:52 AM, Gene Cumm <gene.cumm at gmail.com> wrote:
>> > On Tue, Dec 19, 2017 at 3:47 PM, Jeff Sadowski via Syslinux
>> > <syslinux at zytor.com> wrote:
>> >> I have an odd issue.
>> >> I have one machine that does not display to the monitor when it goes
>> >> to a linux boot loader.
>> >> It has the issue with grub and pxelinux.
>> >>
>> >> I see the bios but between bios and graphics driver I see a blank
>> >> screen.
>> >>
>> >> Any recommendations on how to fix it?
>> >>
>> >> More to it. It is a newer nvidia card, That I need to drive a 4K
>> >> monitor at 60Hz . If I replace it with an old nvidia card I can see it
>> >> fine but it doesn't get me 4K at 60Hz.
>> >>
>> >> In grub I tried setting the resolution to 1024x768 using
>> >>
>> >> GRUB_GFXMODE=1024x768
>> >>
>> >> and ran "upgrade-grub"
>> >>
>> >> But I still ended with a blank screen.
>> >>
>> >> I really want pxelinux more than grub in hopes that some way I could
>> >> boot clonezilla via pxe boot.
>> >> Which I have working for the rest of my machines.
>> >>
>> >> I have a second video card that has the same symptoms in that machine
>> >> but not in another.
>> >> So something about motherboard+video card+(maybe monitor) that causes
>> >> the issue. If someone has some suggestions of something to pass to
>> >> pxelinux via it's config that I could try out I'd much appreciate it.
>> >>
>> >> my pxelinux config looks like so
>> >>
>> >> default vesamenu.c32
>> >> #menu resolution 800 600
>> >> #prompt 1
>> >> #timeout 30
>> >>
>> >> display boot.msg
>> >>
>> >> label local
>> >>   menu label Boot from ^local drive
>> >>   menu default
>> >>   timeout 20
>> >>   kernel chain.c32
>> >>   append hd0
>> >> label memtest86
>> >>   menu label ^Memory test
>> >>   kernel memtest
>> >>   append -
>> >> label Clonezilla-live Stable 2017-02-20 x64
>> >>   menu label Clonezilla Live 2017-02-20 x64 (Stable)
>> >>   kernel cz170220.x64/live/vmlinuz
>> >>   append initrd=cz170220.x64/live/initrd.img boot=live union=overlay
>> >> username=user hostname=clonezilla config quiet components noswap
>> >> edd=on nomodeset nodmraid noeject locales=en_US.UTF-8
>> >> keyboard-layouts=NONE ocs_live_run="ocs-live-general"
>> >> ocs_live_extra_param="" ocs_live_batch=no vga=788
>> >> toram=filesystem.squashfs ip=dhcp net.ifnames=0  splash
>> >> i915.blacklist=yes radeonhd.blacklist=yes nouveau.blacklist=yes
>> >> vmwgfx.enable_fbdev=1 ocs_prerun="dhclient && mount -t nfs
>> >> loki:/ifs/it/sysadmin/clonezilla /home/partimag"
>> >> fetch=tftp://10.0.100.78/cz170220.x64/live/filesystem.squashfs
>> >
>> > For starters, the keyword "quiet" silences all messages from Syslinux
>> > and the Linux kernel.  Most initrds also adhere to this.
>> > "nouveau.blacklist" controls an nVidia driver.
>> >
>> > Consider also firmware upgrades/downgrades to the motherboard and
>> > graphics card.  On occasion, you work around a bug in the current
>> > firmware with a mildly older one.
>> >
>> > Beyond that, it's distro-specific or hardware-specific.
>> >
>> > Also, I hope the initrd/rootfs uses DHCP itself as some DHCP clients,
>> > including some PXE clients, send a DHCPRELEASE, invalidating the lease
>> > to allow other clients to use it.
>> >
>> > --
>> > -Gene

-- 
-Gene