HowTo: Find out the maximum framebuffer resolution

[i3dmaster]

I don't know if anyone has any better solution to find out the max fb resolution of a box, but the way I provided below should be a relative easier one than trying out the framebuffer vga mode matrix one by one. Ok, here we go:

1. You need a ubuntu install cd (or maybe a live cd), whichever one having an option for vga mode that you can pick. I used a dapper daily build install CD which works like a charm.
2. Insert the cd and reboot your box.
3. Boot from the CD and you should see the boot menu. Pick the maximum VGA mode in the list (normally F3 for the vga mode and you should see a list, then go down to the max one), then choose boot to rescue your system (You don't want to do a fresh install just because of this Actually, pick the rescue one isn't going to rescue anything but just need a prompt to your system). Note: If the screen goes black or messed up by using the resolution, then reboot and pick the one above until you get the max resolution that can display everything correctly.
4. Go on to the boot procedure, when it asks where to execute a shell, pick the one saying "execute a shell in the installer environment".
5. When you see the prompt, run this command

cat /proc/cmdline

6. Do you see the vga=xxxx option? That is your maximum framebuffer resolution that your graphic card and the monitor supported. Write it down.
7. Get the CD out and reboot your box to your hard disk normally.
8. Open your favorite editor and edit the /boot/grub/menu.lst file. Go to the line like this:

# nonaltoptions=quite splash

to

# nonaltoptions=quite splash vga=xxxx

. Replace the xxxx to the mode you just wrote down.
9. Save the menu.lst file. Then do

sudo update-grub

.
10. After upgrading the grub system, all your kernel option except single mode should have vga=xxxx added.

An example of my box:
I have an intel graphic card and 20" monitor which I thought it can only support max to 16x12@32 before I did all above, but I found out when I boot from the ubuntu CD, it gave me 1920x1440@16 option. Then I boot from that and fortunately, it supported. Then I changed my grub option to vga=0x34d (which is 1920x1440@16) and now I have 1920x1440 resolution at console mode. Somebody might not like that huge screen with tiny fonts but I like it, its super for coding.

Have fun ...