How-To :: modificando a resolução de tela no GRUB2

E essa vai para aqueles que desejam modificar a resolução de tela vista no GRUB e a sopa de letrinha subsequente.

Devido a uma infelicidade recente, vários componentes do meu PC de casa vieram a queimar (roteador, estabilizador, fonte de 500w real, monitor, etc), passado o susto (já que os componentes internos do PC nada sofreram) fui forçado a adquirir um novo monitor, o qual suporta a resolução de 1920×1200, daí que entra o escopo da dica. Anteriormente meu Grub estava setada com uma resolução de 1024×768, agora com um monitor maior ficou bem tosco, então vamos ver o que é necessaário para modificar a tela do Grub e a nossa querida tela preta.

Requerimento.

Em sua distro instale o pacote hwinfo, o qual nas Debian-based se faz assim:

$ sudo apt-get update
$ sudo apt-get install hwinfo

Daí, execute o comando a seguir para que seja listado os modos suportados pelo seu monitor:

$ sudo hwinfo --framebuffer

Meu resultado disse o seguinte:

$ sudo hwinfo --framebuffer
> hal.1: read hal dataprocess 9358: arguments to dbus_move_error() were incorrect, assertion "(dest) == NULL || !dbus_error_is_set ((dest))" failed in file ../../dbus/dbus-errors.c line 282.
This is normally a bug in some application using the D-Bus library.
libhal.c 3483 : Error unsubscribing to signals, error=The name org.freedesktop.Hal was not provided by any .service files
02: None 00.0: 11001 VESA Framebuffer                           
  [Created at bios.464]
  Unique ID: rdCR.EGLbTnIncc1
  Hardware Class: framebuffer
  Model: "NVIDIA G96 Board - 09730003"
  Vendor: "NVIDIA Corporation"
  Device: "G96 Board - 09730003"
  SubVendor: "NVIDIA"
  SubDevice: 
  Revision: "Chip Rev"
  Memory Size: 14 MB
  Memory Range: 0xf1000000-0xf1dfffff (rw)
  Mode 0x0300: 640x400 (+640), 8 bits
  Mode 0x0301: 640x480 (+640), 8 bits
  Mode 0x0303: 800x600 (+800), 8 bits
  Mode 0x0305: 1024x768 (+1024), 8 bits
  Mode 0x0307: 1280x1024 (+1280), 8 bits
  Mode 0x030e: 320x200 (+640), 16 bits
  Mode 0x030f: 320x200 (+1280), 24 bits
  Mode 0x0311: 640x480 (+1280), 16 bits
  Mode 0x0312: 640x480 (+2560), 24 bits
  Mode 0x0314: 800x600 (+1600), 16 bits
  Mode 0x0315: 800x600 (+3200), 24 bits
  Mode 0x0317: 1024x768 (+2048), 16 bits
  Mode 0x0318: 1024x768 (+4096), 24 bits
  Mode 0x031a: 1280x1024 (+2560), 16 bits
  Mode 0x031b: 1280x1024 (+5120), 24 bits
  Mode 0x0330: 320x200 (+320), 8 bits
  Mode 0x0331: 320x400 (+320), 8 bits
  Mode 0x0332: 320x400 (+640), 16 bits
  Mode 0x0333: 320x400 (+1280), 24 bits
  Mode 0x0334: 320x240 (+320), 8 bits
  Mode 0x0335: 320x240 (+640), 16 bits
  Mode 0x0336: 320x240 (+1280), 24 bits
  Mode 0x033d: 640x400 (+1280), 16 bits
  Mode 0x033e: 640x400 (+2560), 24 bits
  Mode 0x0345: 1600x1200 (+1600), 8 bits
  Mode 0x0346: 1600x1200 (+3200), 16 bits
  Mode 0x0347: 1400x1050 (+1400), 8 bits
  Mode 0x0348: 1400x1050 (+2800), 16 bits
  Mode 0x0349: 1400x1050 (+5600), 24 bits
  Mode 0x034a: 1600x1200 (+6400), 24 bits
  Mode 0x0352: 2048x1536 (+8192), 24 bits
  Mode 0x0360: 1280x800 (+1280), 8 bits
  Mode 0x0361: 1280x800 (+5120), 24 bits
  Mode 0x0362: 768x480 (+768), 8 bits
  Mode 0x0364: 1440x900 (+1440), 8 bits
  Mode 0x0365: 1440x900 (+5760), 24 bits
  Mode 0x0368: 1680x1050 (+1680), 8 bits
  Mode 0x0369: 1680x1050 (+6720), 24 bits
  Mode 0x037b: 1280x720 (+5120), 24 bits
  Mode 0x037c: 1920x1200 (+1920), 8 bits
  Mode 0x037d: 1920x1200 (+7680), 24 bits
  Config Status: cfg=new, avail=yes, need=no, active=unknown

A resolução máxima suportada é a 1920x1200x24bits, então vamos adicioná-la ao arquivo /etc/default/grub:

$ sudo nano /etc/default/grub

As linhas a serem modificadas foram as seguintes:

de:

GRUB_CMDLINE_LINUX_DEFAULT="quiet gfxpayload=1024x768x24"

para:

GRUB_CMDLINE_LINUX_DEFAULT="quiet gfxpayload=1920x1200x24"

E de:

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
GRUB_GFXMODE=1024x768

para:

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
GRUB_GFXMODE=1920x1200
GRUB_GFXPAYLOAD_LINUX=keep

Abaixo segue o modelo do meu arquivo /etc/default/grub:

# If you change this file, run 'update-grub' afterwards to update
# /boot/grub/grub.cfg.
# For full documentation of the options in this file, see:
#   info -f grub -n 'Simple configuration'

GRUB_DEFAULT=0
GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet gfxpayload=1920x1200x24 threadirqs"
GRUB_CMDLINE_LINUX=""

# Uncomment to enable BadRAM filtering, modify to suit your needs
# This works with Linux (no patch required) and with any kernel that obtains
# the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...)
#GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef"

# Uncomment to disable graphical terminal (grub-pc only)
#GRUB_TERMINAL=console

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
GRUB_GFXMODE=1920x1200
GRUB_GFXPAYLOAD_LINUX=keep

# Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux
#GRUB_DISABLE_LINUX_UUID=true

# Uncomment to disable generation of recovery mode menu entries
#GRUB_DISABLE_RECOVERY="true"

# Uncomment to get a beep at grub start
#GRUB_INIT_TUNE="480 440 1"

Após modificar o arquivo, execute:

$ sudo update-grub

Quando conseguir tirar uma foto decente, acrescentarei as mesmas na dica.

IntÉ!