Dear @Erhard-Henkes and C++/OSDev community members, good day and happy coming 2019 to you! I built the open source BIOS "coreboot+SeaBIOS" for my quadcore AMD A10-5750M based Lenovo G505S coreboot-supported laptop with 16 GB RAM ( for those who are interested, check this coreboot Supported Motherboards list - https://coreboot.org/status/board-status.html - maybe you already have a PC from this list or a real chance to get one ) . Then added a PrettyOS floppy image to coreboot.rom by using this command: (with LZMA compression 1440KB ---> 375KB to save some space inside the SPI flash BIOS chip for another cool stuff, by itself coreboot+SeaBIOS takes less than 1MB out of 4MB chip, much less than fat proprietary UEFI 3.5MB ) ./build/cbfstool ./build/coreboot.rom add -f ./prettyos.img -n floppyimg/prettyos.lzma -t raw -c lzma Flashed this coreboot.rom inside my laptop's BIOS chip and tried booting PrettyOS from SeaBIOS boot menu ! However I ran into the following problem: Loading Second Stage Bootloader XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX GTD installed Unreal Mode entered Loading Kernel... Floppy Disk Motor switched off Switching to Protected Mode (PM)..._ ^^^ and blinking _ cursor at the end of line above Also my font successfully changed to PrettyOS style. What might be the reason that PrettyOS got stuck at "Switching to Protected Mode" ? Sadly this problem isn't reproduced at QEMU or VirtualBox, but I could help you to debug it, waiting for your instructions Best regards, Ivan Ivanov