Hello, I'm trying to optimize a GRUB 2 core.img. I have made a custom minimal core.img for a x64_86 laptop with BIOS/GPT (with partition bios_grub) using grub-mkimage.- load required module - custom keyboard layout when typing passphase - decrypt the device- load /boot/grub/grub.cfg from decrypted deviceIt works fine and I can type my strong password without rebooting many times due to typos errors. But I would like to optimize my little core.img with some video(s) modules because characters which are printed on the screen at this 1st stage are very very big.
The grub which is on the encrypted /boot volume of the Ubuntu install called at 2nd stage are printed normaly (not so big). I'm not searching any theme or custom gfx just normal size. I have added some module to my little core.img for the 1st stage as these onse : normal gfxterm gfxterm_menu all_video videotest videoinfo vbe vga video_bochs video_cirrus. videotest and videoinfo are working and videotest give me a preferred resolution of 1200x800.I tried to load manually some modules and change video screen resolution at the grub console prompt: insmod all_videoinsmod gfxtermset gfxmode=auto terminal_output auto (tried too with terminal_output gfxterm) terminal_output gfxterm But nothing change (only one ... with pager=1 output from command as set is no more split per page) Standard video mode are working well on the 2nd stage grub which is controlled by ubuntu and grub scripts. I have read the generated grub.cfg from it and I don't not see any additional module which are loaded with insmod. I didn't add any value to GFX_ variable in /etc/default/grub so it is an "auto-mode" which is perfect and would be perfect for the 1st stage core.img. What are the default modules that a standard grub is loading by default when all modules are available inside the /boot/grub/plateform/*.mod for this laptop i386-pc ? What are the commands required to load and change video mode resolution from the grub console prompt (to test before adding it to the core-grub.cfg) ? I tried to find some references about the grub console prompt and video mode but it is always related to the /etc/default/grub variables. Minimal core.img insmod echo insmod gzio insmod part_gpt insmod cryptodisk insmod luks insmod gcry_rijndael insmod gcry_rijndael insmod gcry_sha256 insmod lvm insmod ext2 insmod keylayouts insmod at_keyboard echo "Starting GRUB..." set root=(memdisk) set prefix=($root)/ terminal_input at_keyboard keymap /fr.gkb cryptomount -u xyz123 set root='lvmid/aaaa-bbbb-cccc-xxxx/dddd-eeee-gggg-yyyy' set prefix=($root)/grub configfile grub.cfg Thanks you in advance for your help. Regards,Fabien
