Gregory Bartholomew
2021-Mar-18 14:42 UTC
[syslinux] Equivalent to GRUB_GFXPAYLOAD_LINUX=keep with vesamenu?
On Thu, Mar 18, 2021 at 8:02 AM nerdopolis via Syslinux < syslinux at syslinux.org> wrote:> On Thursday, March 18, 2021 12:58:46 AM EDT Gregory Bartholomew wrote: > > On Wed, Mar 17, 2021 at 10:35 PM nerdopolis via Syslinux < > > syslinux at syslinux.org> wrote: > > > > > ... > > > OK, I am realizing that in syslinux there IS a special case for > > > vga=current / vga> > > > > > > https://repo.or.cz/syslinux.git/blob/346d2278e23f1b9f02903506753263ad7226de58:/com32/lib/syslinux/load_linux.c#l497 > > > > > > Trying that option I do see much different behavior. It doesn't flush > the > > > display, as if though going into text mode (which is a good start), > but it > > > appears The kernel never creates the /dev/fb0 device like it does with > grub > > > starting it. > > > ... > > > > > > > From > > > https://github.com/torvalds/linux/blob/master/Documentation/fb/vesafb.rst: > > > > " ... You should compile in both vgacon (for text mode) and vesafb (for > > graphics mode). Which of them takes over the console depends on whenever > > the specified mode is text or graphics. ..." > > > > I wonder if the kernel is falling back to text mode because it doesn't > > recognize "vga=current" as a graphics mode? Maybe you can force it with > > "video=vesafb:on" (or maybe "video=efifb:on" if you are using > syslinux.efi). > > > I tried the VGA option as hex, and as =current, so it might not be the > kernel > not recognizing it, but I wonder if I am missing something in the dmesg > output... > > I tried video=vesafb:on and that doesn't seem to work > BTW: I am using isolinux.bin > > ...Sorry, I'm down to just random things to try at this point, but maybe try substituting "uvesafb" for "vesafb". Or maybe try "rd.driver.pre=uvesafb" instead of "video=...". I'm really out of ideas at this point. Sorry. I think you just need to get the right kernel module to load to get the /dev/fb0 device to show up. Let us know if you figure it out.
Gregory Bartholomew
2021-Mar-18 15:25 UTC
[syslinux] Equivalent to GRUB_GFXPAYLOAD_LINUX=keep with vesamenu?
Just one last idea ... there is a "fb" kernel parameter which is supposed to enable the framebuffer device: https://www.kernel.org/doc/html/v4.14/admin-guide/kernel-parameters.html#:~:text=The%20frame%20buffer%20device%20is%20enabled Maybe try that? On Thu, Mar 18, 2021 at 9:42 AM Gregory Bartholomew < gregory.lee.bartholomew at gmail.com> wrote:> On Thu, Mar 18, 2021 at 8:02 AM nerdopolis via Syslinux < > syslinux at syslinux.org> wrote: > >> On Thursday, March 18, 2021 12:58:46 AM EDT Gregory Bartholomew wrote: >> > On Wed, Mar 17, 2021 at 10:35 PM nerdopolis via Syslinux < >> > syslinux at syslinux.org> wrote: >> > >> > > ... >> > > OK, I am realizing that in syslinux there IS a special case for >> > > vga=current / vga>> > > >> > > >> https://repo.or.cz/syslinux.git/blob/346d2278e23f1b9f02903506753263ad7226de58:/com32/lib/syslinux/load_linux.c#l497 >> > > >> > > Trying that option I do see much different behavior. It doesn't flush >> the >> > > display, as if though going into text mode (which is a good start), >> but it >> > > appears The kernel never creates the /dev/fb0 device like it does >> with grub >> > > starting it. >> > > ... >> > > >> > >> > From >> > >> https://github.com/torvalds/linux/blob/master/Documentation/fb/vesafb.rst >> : >> > >> > " ... You should compile in both vgacon (for text mode) and vesafb (for >> > graphics mode). Which of them takes over the console depends on whenever >> > the specified mode is text or graphics. ..." >> > >> > I wonder if the kernel is falling back to text mode because it doesn't >> > recognize "vga=current" as a graphics mode? Maybe you can force it with >> > "video=vesafb:on" (or maybe "video=efifb:on" if you are using >> syslinux.efi). >> > >> I tried the VGA option as hex, and as =current, so it might not be the >> kernel >> not recognizing it, but I wonder if I am missing something in the dmesg >> output... >> >> I tried video=vesafb:on and that doesn't seem to work >> BTW: I am using isolinux.bin >> >> ... > > > Sorry, I'm down to just random things to try at this point, but maybe try > substituting "uvesafb" for "vesafb". Or maybe try "rd.driver.pre=uvesafb" > instead of "video=...". I'm really out of ideas at this point. Sorry. I > think you just need to get the right kernel module to load to get the > /dev/fb0 device to show up. Let us know if you figure it out. >