Vas problem se ocividne tyka chybne nastaveneho framebufferu. Je nutne nastavit správný boot parametr kernelu 'vga='. Jakou ma nabyvat hodnotu se lze docist treba v dokumentaci, ktera je u zdroju jadra. Je to zavisle na pozadovanem rozliseni. Ja bych vam sem i tu hodnotu napsal, zel jste neuvedl rozliseni, ktere pozadujete.

Switching modes is done using the vga=... boot parameter.

Here are those VESA mode numbers:

| 640x480 800x600 1024x768 1280x1024
----+-------------------------------------
256 | 0x101 0x103 0x105 0x107
32k | 0x110 0x113 0x116 0x119
64k | 0x111 0x114 0x117 0x11A
16M | 0x112 0x115 0x118 0x11B

The video mode number of the Linux kernel is the VESA mode number plus
0x200.

Linux_kernel_mode_number = VESA_mode_number + 0x200

So the table for the Kernel mode numbers are:

| 640x480 800x600 1024x768 1280x1024
----+-------------------------------------
256 | 0x301 0x303 0x305 0x307
32k | 0x310 0x313 0x316 0x319
64k | 0x311 0x314 0x317 0x31A
16M | 0x312 0x315 0x318 0x31B