Francis Moreau
2014-Jul-01 17:16 UTC
[syslinux] Problem: vga TEXT mode has only 8 colors when booting with syslinux
Hello,
First of all, I'm really not an expert so please correct me if I'm
saying anything wrong.
I noticed a difference when using grub2 or syslinux in my linux virtual
console (tty[1-5]) which uses VGA text mode (no graphical mode). To be
sure that I'm using this mode, I did:
$ dmesg | grep -i vga
Console: colour VGA+ 80x25
In my understanding when using the VGA text mode, 16 colours are available.
However, if I try to display those 16 colours after syslinux booting my
system, I can see only 8 different colours. Here's my syslinux.cfg:
DEFAULT linux
PROMPT 0
UI menu.c32
MENU TITLE Linux
LABEL linux
MENU LABEL linux
LINUX ../vmlinuz
INITRD ../initrd.img
APPEND root=PARTUUID=c3b28cc5-93d5-4cdc-b86e-857231520205
rw quiet
The same application running on the same system displays 16 colours if
booted with grub2 (but still using VGA text mode). FWIW, grub2's config
is using:
GRUB_TERMINAL=console
GRUB_GFXPAYLOAD_LINUX=keep
Could anybody explain me why there's such difference and why syslinux
leaves the VGA text mode with only 8 colours where there should be 16 ?
Thanks.
H. Peter Anvin
2014-Jul-07 18:15 UTC
[syslinux] Problem: vga TEXT mode has only 8 colors when booting with syslinux
On 07/01/2014 10:16 AM, Francis Moreau wrote:> Hello, > > First of all, I'm really not an expert so please correct me if I'm > saying anything wrong. > > I noticed a difference when using grub2 or syslinux in my linux virtual > console (tty[1-5]) which uses VGA text mode (no graphical mode). To be > sure that I'm using this mode, I did: > > $ dmesg | grep -i vga > Console: colour VGA+ 80x25 > > In my understanding when using the VGA text mode, 16 colours are available. > > However, if I try to display those 16 colours after syslinux booting my > system, I can see only 8 different colours. Here's my syslinux.cfg: > > DEFAULT linux > PROMPT 0 > UI menu.c32 > MENU TITLE Linux > > LABEL linux > MENU LABEL linux > LINUX ../vmlinuz > INITRD ../initrd.img > APPEND root=PARTUUID=c3b28cc5-93d5-4cdc-b86e-857231520205 > rw quiet > > The same application running on the same system displays 16 colours if > booted with grub2 (but still using VGA text mode). FWIW, grub2's config > is using: > > GRUB_TERMINAL=console > GRUB_GFXPAYLOAD_LINUX=keep > > Could anybody explain me why there's such difference and why syslinux > leaves the VGA text mode with only 8 colours where there should be 16 ? >What system font are you using? -hpa
Francis Moreau
2014-Jul-07 18:26 UTC
[syslinux] Problem: vga TEXT mode has only 8 colors when booting with syslinux
On 07/07/2014 08:15 PM, H. Peter Anvin wrote:> On 07/01/2014 10:16 AM, Francis Moreau wrote: >> Hello, >> >> First of all, I'm really not an expert so please correct me if I'm >> saying anything wrong. >> >> I noticed a difference when using grub2 or syslinux in my linux virtual >> console (tty[1-5]) which uses VGA text mode (no graphical mode). To be >> sure that I'm using this mode, I did: >> >> $ dmesg | grep -i vga >> Console: colour VGA+ 80x25 >> >> In my understanding when using the VGA text mode, 16 colours are available. >> >> However, if I try to display those 16 colours after syslinux booting my >> system, I can see only 8 different colours. Here's my syslinux.cfg: >> >> DEFAULT linux >> PROMPT 0 >> UI menu.c32 >> MENU TITLE Linux >> >> LABEL linux >> MENU LABEL linux >> LINUX ../vmlinuz >> INITRD ../initrd.img >> APPEND root=PARTUUID=c3b28cc5-93d5-4cdc-b86e-857231520205 >> rw quiet >> >> The same application running on the same system displays 16 colours if >> booted with grub2 (but still using VGA text mode). FWIW, grub2's config >> is using: >> >> GRUB_TERMINAL=console >> GRUB_GFXPAYLOAD_LINUX=keep >> >> Could anybody explain me why there's such difference and why syslinux >> leaves the VGA text mode with only 8 colours where there should be 16 ? >> > > What system font are you using?Hm, I guess that the default one but how can I figure this out ? Thanks.